Introduction

The following are the events for the OpenJDK 17 (jdk-17.0.13+3, 15-August-2024), and Graal VM 23.0.3 (jdk-17.0.10) . The events are collected from the event configuration and the source code. Visit jfreventcollector for more information. this is also the place you can contribute additional event descriptions, if you don't want to contribute them directly to the OpenJDK. The site generator lives on GitHub too.

This page is maintained by Johannes Bechberger of the SapMachine team at SAP and contributors.

Some events have fake end times / durations, these are hidden in the event description here.

Flight Recorder

DumpReason

default profiling startTime 11 17 21 23 24

Category: Flight Recorder

Who requested the recording and why

Configuration	enabled
default	true
profiling	true

Field	Type	Description
reason	string	Reason Reason for writing recording data to disk
recordingId	int	Recording Id Id of the recording that triggered the dump, or -1 if it was not related to a recording

DataLoss

default profiling startTime 11 17 21 23 24 graal vm

Category: Flight Recorder

Data could not be copied out from a buffer, typically because of contention

Configuration	enabled
default	true
profiling	true

Field	Type	Description
amount	ulong: bytes	Amount Amount lost data
total	ulong: bytes	Total Total lost amount for thread

Flush

experimental startTime duration 14 17 21 23 24

Category: Flight Recorder

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	threshold
default	false	0 ns
profiling	false	0 ns

Field	Type	Description
flushId	ulong	Flush Identifier
elements	ulong	Elements Written
size	ulong: bytes	Size Written

Examples 3

elements	ulong	24766
flushId	ulong	79
size	ulong: bytes	4650622
startTime	long: millis	86771244083

elements	ulong	16521
flushId	ulong	29
size	ulong: bytes	2486665
startTime	long: millis	31336483083

elements	ulong	35
flushId	ulong	41
size	ulong: bytes	7714
startTime	long: millis	42777691250

ActiveRecording

default profiling startTime duration stackTrace 11 17 21 23 24

Source src/jdk.jfr/share/classes/jdk/jfr/events/ActiveRecordingEvent.java

Category: Flight Recorder

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled
default	true
profiling	true

Field	Type	Description
id	long	Id
name	string	Name Consider contributing a description to jfreventcollector.
destination	string	Destination Consider contributing a description to jfreventcollector.
maxAge	long: millis	Max Age
flushInterval	long: millis 14+	Flush Interval
maxSize	long: bytes	Max Size
recordingStart	long: epochmillis	Start Time
recordingDuration	long: millis	Recording Duration

Examples 3

destination	string	[...]/code/experiments/jfreventcollector/jfr/sample_UseSerialGC.jfr
flushInterval	long: millis	1000
id	long	1
maxAge	long: millis	9223372036854775807
maxSize	long: bytes	262144000
name	string	1
recordingDuration	long: millis	9223372036854775807
recordingStart	long: epochmillis	1702899981921
stackTrace	StackTrace	null
startTime	long: millis	96707998458

destination	string	[...]/code/experiments/jfreventcollector/jfr/sample_UseParallelGC.jfr
flushInterval	long: millis	1000
id	long	1
maxAge	long: millis	9223372036854775807
maxSize	long: bytes	0
name	string	1
recordingDuration	long: millis	9223372036854775807
recordingStart	long: epochmillis	1702899886817
stackTrace	StackTrace	null
startTime	long: millis	416785542

destination	string	[...]/code/experiments/jfreventcollector/jfr/sample_UseG1GC.jfr
flushInterval	long: millis	1000
id	long	1
maxAge	long: millis	9223372036854775807
maxSize	long: bytes	262144000
name	string	1
recordingDuration	long: millis	9223372036854775807
recordingStart	long: epochmillis	1702902685041
stackTrace	StackTrace	null
startTime	long: millis	36094290375

ActiveSetting

default profiling startTime duration stackTrace 11 17 21 23 24

Source src/jdk.jfr/share/classes/jdk/jfr/events/ActiveSettingEvent.java

Category: Flight Recorder

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled
default	true
profiling	true

Field	Type	Description
id	long	Event Id
name	string	Setting Name
value	string	Setting Value

Examples 3

id	long	33
name	string	enabled
stackTrace	StackTrace	null
startTime	long: millis	669832834
value	string	true

id	long	57
name	string	enabled
stackTrace	StackTrace	null
startTime	long: millis	360834042
value	string	true

id	long	26
name	string	enabled
stackTrace	StackTrace	null
startTime	long: millis	416785542
value	string	true

JVM

JVMInformation

default profiling startTime duration end of every chunk 11 17 21 23 24 graal vm

Category: Java Virtual Machine

Description of JVM and the Java application

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
jvmName	string	JVM Name
jvmVersion	string	JVM Version
jvmArguments	string	JVM Command Line Arguments
jvmFlags	string	JVM Settings File Arguments
javaArguments	string	Java Application Arguments
jvmStartTime	long: epochmillis	JVM Start Time
pid	long	Process Identifier

Examples 3

javaArguments	string	[...]/code/experiments/jfreventcollector/.cache/renaissance.jar -t 5 -r 1 all
jvmArguments	string	-XX:StartFlightRecording=filename=[...]/code/experiments/jfreventcollector/jfr/sample_UseParallelGC.jfr,settings=[...]/code/experiments/jfreventcollector/.cache/jfc.jfc -XX:+UseParallelGC
jvmFlags	string	null
jvmName	string	OpenJDK 64-Bit Server VM
jvmStartTime	long: epochmillis	1702899886436
jvmVersion	string	OpenJDK 64-Bit Server VM (21.0.1+12-LTS) for bsd-aarch64 JRE (21.0.1+12-LTS), built on 2023-10-17T00:00:00Z by "admin" with clang Apple LLVM 12.0.0 (clang-1200.0.32.29)
pid	long	13981
startTime	long: millis	17889793125

javaArguments	string	[...]/code/experiments/jfreventcollector/.cache/renaissance.jar -t 5 -r 1 all
jvmArguments	string	-XX:StartFlightRecording=filename=[...]/code/experiments/jfreventcollector/jfr/sample_UseG1GC.jfr,settings=[...]/code/experiments/jfreventcollector/.cache/jfc.jfc -XX:+UseG1GC
jvmFlags	string	null
jvmName	string	OpenJDK 64-Bit Server VM
jvmStartTime	long: epochmillis	1702902684442
jvmVersion	string	OpenJDK 64-Bit Server VM (21.0.1+12-LTS) for bsd-aarch64 JRE (21.0.1+12-LTS), built on 2023-10-17T00:00:00Z by "admin" with clang Apple LLVM 12.0.0 (clang-1200.0.32.29)
pid	long	21922
startTime	long: millis	75168554750

javaArguments	string	[...]/code/experiments/jfreventcollector/.cache/renaissance.jar -t 5 -r 1 all
jvmArguments	string	-XX:StartFlightRecording=filename=[...]/code/experiments/jfreventcollector/jfr/sample_UseSerialGC.jfr,settings=[...]/code/experiments/jfreventcollector/.cache/jfc.jfc -XX:+UseSerialGC
jvmFlags	string	null
jvmName	string	OpenJDK 64-Bit Server VM
jvmStartTime	long: epochmillis	1702899981604
jvmVersion	string	OpenJDK 64-Bit Server VM (21.0.1+12-LTS) for bsd-aarch64 JRE (21.0.1+12-LTS), built on 2023-10-17T00:00:00Z by "admin" with clang Apple LLVM 12.0.0 (clang-1200.0.32.29)
pid	long	14273
startTime	long: millis	75961227292

InitialSystemProperty

default profiling startTime end of every chunk 11 17 21 23 24 graal vm

Category: Java Virtual Machine

System Property at JVM start

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
key	string	Key
value	string	Value

Examples 3

key	string	java.vm.compressedOopsMode
startTime	long: millis	422632500
value	string	Zero based

key	string	jdk.debug
startTime	long: millis	52080831625
value	string	release

key	string	jdk.debug
startTime	long: millis	50916130834
value	string	release

JVM: Class Loading

ClassLoad

startTime duration eventThread stackTrace 11 17 21 23 24

Category: Java Virtual Machine / Class Loading

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	stackTrace	threshold
default	false	true	0 ms
profiling	false	true	0 ms

Field	Type	Description
loadedClass	Class	Loaded Class Consider contributing a description to jfreventcollector.
definingClassLoader	ClassLoader	Defining Class Loader Consider contributing a description to jfreventcollector.
initiatingClassLoader	ClassLoader	Initiating Class Loader Consider contributing a description to jfreventcollector.

Examples 3

definingClassLoader	ClassLoader
name	string	bootstrap
type	Class	null
initiatingClassLoader	ClassLoader
name	string	bootstrap
type	Class	null
loadedClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/regex/Pattern$Start
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/regex
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	425
lineNumber	int	1967
method	Method
descriptor	string	()V
hidden	boolean	false
modifiers	int	2
name	string	compile
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/util/regex/Pattern
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/regex
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	396515625

definingClassLoader	ClassLoader
name	string	bootstrap
type	Class	null
initiatingClassLoader	ClassLoader
name	string	bootstrap
type	Class	null
loadedClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/text/DecimalFormatSymbols
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/text
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	22
lineNumber	int	2032
method	Method
descriptor	string	(Ljava/util/Locale;)Ljava/text/DecimalFormatSymbols;
hidden	boolean	false
modifiers	int	10
name	string	getDecimalFormatSymbols
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/util/Formatter
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	725916750

definingClassLoader	ClassLoader
name	string	app
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	jdk/internal/loader/ClassLoaders$AppClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	jdk/internal/loader
initiatingClassLoader	ClassLoader
name	string	app
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	jdk/internal/loader/ClassLoaders$AppClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	jdk/internal/loader
loadedClass	Class
classLoader	ClassLoader
name	string	app
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	jdk/internal/loader/ClassLoaders$AppClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	jdk/internal/loader
hidden	boolean	false
modifiers	int	48
name	string	org/renaissance/core/ModuleLoader$ModuleLoadingException
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	app
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	jdk/internal/loader/ClassLoaders$AppClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	jdk/internal/loader
location	string	null
name	string	null
version	string	null
name	string	org/renaissance/core
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	(Z)[Ljava/lang/reflect/Method;
hidden	boolean	false
modifiers	int	258
name	string	getDeclaredMethods0
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/lang/Class
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	449148625

ClassDefine

startTime eventThread stackTrace 11 17 21 23 24

Category: Java Virtual Machine / Class Loading

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	stackTrace
default	false	true
profiling	false	true

Field	Type	Description
definedClass	Class	Defined Class Consider contributing a description to jfreventcollector.
definingClassLoader	ClassLoader	Defining Class Loader Consider contributing a description to jfreventcollector.

Examples 3

definedClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/ResourceBundle$Control
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util
definingClassLoader	ClassLoader
name	string	bootstrap
type	Class	null
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	70
method	Method
descriptor	string	()V
hidden	boolean	false
modifiers	int	8
name	string	<clinit>
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	sun/util/resources/LocaleData
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	sun/util/resources
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	736612750

definedClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	jdk/internal/module/ModulePatcher$PatchedModuleReader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	jdk/internal/module
definingClassLoader	ClassLoader
name	string	bootstrap
type	Class	null
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	35
lineNumber	int	802
method	Method
descriptor	string	(Ljava/lang/String;Ljdk/internal/loader/BuiltinClassLoader$LoadedModule;)Ljava/lang/Class;
hidden	boolean	false
modifiers	int	2
name	string	defineClass
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	jdk/internal/loader/BuiltinClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	jdk/internal/loader
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	401631125

definedClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	1537
name	string	sun/util/logging/PlatformLogger$ConfigurableBridge
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	sun/util/logging
definingClassLoader	ClassLoader
name	string	bootstrap
type	Class	null
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	10
lineNumber	int	66
method	Method
descriptor	string	()V
hidden	boolean	false
modifiers	int	1
name	string	<init>
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/logging/SimpleFormatter
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.logging
name	string	java.logging
version	string	21.0.1
name	string	java/util/logging
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	453813333

ClassRedefinition

default profiling startTime 15 17 21 23 24

Category: Java Virtual Machine / Class Loading

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled
default	true
profiling	true

Field	Type	Description
redefinedClass	Class	Redefined Class Consider contributing a description to jfreventcollector.
classModificationCount	int	Class Modification Count The number of times the class has changed
redefinitionId	ulong	Class Redefinition Id

RedefineClasses

default profiling startTime duration eventThread stackTrace 15 17 21 23 24

Category: Java Virtual Machine / Class Loading

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	stackTrace	threshold
default	true	true	0 ms
profiling	true	true	0 ms

Field	Type	Description
classCount	int	Class Count
redefinitionId	ulong	Class Redefinition Id

RetransformClasses

default profiling startTime duration eventThread stackTrace 15 17 21 23 24

Category: Java Virtual Machine / Class Loading

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	stackTrace	threshold
default	true	true	0 ms
profiling	true	true	0 ms

Field	Type	Description
classCount	int	Class Count
redefinitionId	ulong	Class Redefinition Id

ClassUnload

startTime eventThread 11 17 21 23 24

Category: Java Virtual Machine / Class Loading

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled
default	false
profiling	false

Field	Type	Description
unloadedClass	Class	Unloaded Class Consider contributing a description to jfreventcollector.
definingClassLoader	ClassLoader	Defining Class Loader Consider contributing a description to jfreventcollector.

Examples 3

definingClassLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
startTime	long: millis	4558702292
unloadedClass	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	false
modifiers	int	1537
name	string	scala/collection/immutable/SortedSet
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	scala/collection/immutable

definingClassLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
startTime	long: millis	5993964959
unloadedClass	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	false
modifiers	int	1056
name	string	org/sparkproject/guava/collect/AbstractMapEntry
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	org/sparkproject/guava/collect

definingClassLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
startTime	long: millis	3889393250
unloadedClass	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	true
modifiers	int	4144
name	string	org.apache.spark.internal.config.ConfigBuilder$$Lambda+0x0000000800373308/312565954
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	org/apache/spark/internal/config

JVM: Code Cache

CodeCacheFull

default profiling startTime eventThread 11 17 21 23 24

Category: Java Virtual Machine / Code Cache

A code heap is full, this leads to disabling the compiler

Configuration	enabled
default	true
profiling	true

Field	Type	Description
codeBlobType	CodeBlobType	Code Heap Consider contributing a description to jfreventcollector.
startAddress	ulong: address	Start Address
commitedTopAddress	ulong: address	Commited Top
reservedTopAddress	ulong: address	Reserved Top
entryCount	int	Entries
methodCount	int	Methods
adaptorCount	int	Adaptors
unallocatedCapacity	ulong: bytes	Unallocated
fullCount	int	Full Count
codeCacheMaxCapacity	ulong: bytes 17+	Code Cache Maximum Capacity

CodeCacheStatistics

default profiling startTime every chunk 11 17 21 23 24

Category: Java Virtual Machine / Code Cache

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	everyChunk
profiling	true	everyChunk

Field	Type	Description
codeBlobType	CodeBlobType	Code Heap Consider contributing a description to jfreventcollector.
startAddress	ulong: address	Start Address
reservedTopAddress	ulong: address	Reserved Top
entryCount	int	Entries
methodCount	int	Methods
adaptorCount	int	Adaptors
unallocatedCapacity	ulong: bytes	Unallocated
fullCount	int	Full Count

Examples 3

adaptorCount	int	642
codeBlobType	CodeBlobType	CodeHeap 'non-nmethods'
entryCount	int	734
fullCount	int	0
methodCount	int	0
reservedTopAddress	ulong: address	4610097152
startAddress	ulong: address	4604248064
startTime	long: millis	75962738000
unallocatedCapacity	ulong: bytes	4339072

adaptorCount	int	0
codeBlobType	CodeBlobType	CodeHeap 'non-profiled nmethods'
entryCount	int	4087
fullCount	int	0
methodCount	int	4087
reservedTopAddress	ulong: address	5217714176
startAddress	ulong: address	5094801408
startTime	long: millis	93747384250
unallocatedCapacity	ulong: bytes	114293504

adaptorCount	int	0
codeBlobType	CodeBlobType	CodeHeap 'non-profiled nmethods'
entryCount	int	3328
fullCount	int	0
methodCount	int	3328
reservedTopAddress	ulong: address	4771921920
startAddress	ulong: address	4649009152
startTime	long: millis	26911106542
unallocatedCapacity	ulong: bytes	116457728

CodeCacheConfiguration

default profiling startTime end of every chunk 11 17 21 23 24

Category: Java Virtual Machine / Code Cache

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
initialSize	ulong: bytes	Initial Size
reservedSize	ulong: bytes	Reserved Size
nonNMethodSize	ulong: bytes	Non-nmethod Size
profiledSize	ulong: bytes	Profiled Size
nonProfiledSize	ulong: bytes	Non-profiled Size
expansionSize	ulong: bytes	Expansion size
minBlockLength	ulong: bytes	Minimum Block Length
startAddress	ulong: address	Start Address
reservedTopAddress	ulong: address	Reserved Top

Examples 3

expansionSize	ulong: bytes	65536
initialSize	ulong: bytes	2555904
minBlockLength	ulong: bytes	6
nonNMethodSize	ulong: bytes	5839564
nonProfiledSize	ulong: bytes	122909338
profiledSize	ulong: bytes	122909338
reservedSize	ulong: bytes	251658240
reservedTopAddress	ulong: address	4733009920
startAddress	ulong: address	4481351680
startTime	long: millis	30519908542

expansionSize	ulong: bytes	65536
initialSize	ulong: bytes	2555904
minBlockLength	ulong: bytes	6
nonNMethodSize	ulong: bytes	5839564
nonProfiledSize	ulong: bytes	122909338
profiledSize	ulong: bytes	122909338
reservedSize	ulong: bytes	251658240
reservedTopAddress	ulong: address	4771921920
startAddress	ulong: address	4520263680
startTime	long: millis	22150019750

expansionSize	ulong: bytes	65536
initialSize	ulong: bytes	2555904
minBlockLength	ulong: bytes	6
nonNMethodSize	ulong: bytes	5839564
nonProfiledSize	ulong: bytes	122909338
profiledSize	ulong: bytes	122909338
reservedSize	ulong: bytes	251658240
reservedTopAddress	ulong: address	5217714176
startAddress	ulong: address	4966055936
startTime	long: millis	30586818958

JVM: Code Sweeper

SweepCodeCache

default profiling startTime duration eventThread 11 17 until JDK 20

Category: Java Virtual Machine / Code Sweeper

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	threshold
default	true	100 ms
profiling	true	100 ms

Field	Type	Description
sweepId	int	Sweep Identifier
sweptCount	uint	Methods Swept
flushedCount	uint	Methods Flushed
zombifiedCount	uint	Methods Zombified

CodeSweeperStatistics

default profiling startTime every chunk 11 17 until JDK 20

Category: Java Virtual Machine / Code Sweeper

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	everyChunk
profiling	true	everyChunk

Field	Type	Description
sweepCount	int	Sweeps
methodReclaimedCount	int	Methods Reclaimed
totalSweepTime	Tickspan	Time Spent Sweeping
peakFractionTime	Tickspan	Peak Time Fraction Sweep
peakSweepTime	Tickspan	Peak Time Full Sweep

CodeSweeperConfiguration

default profiling startTime end of every chunk 11 17 until JDK 20

Category: Java Virtual Machine / Code Sweeper

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
sweeperEnabled	boolean	Code Sweeper Enabled
flushingEnabled	boolean	Code Cache Flushing Enabled
sweepThreshold	ulong: bytes 17 until JDK 20	Sweep Threshold

JVM: Compiler

JITRestart

default profiling startTime eventThread 17 21 23 24

Category: Java Virtual Machine / Compiler

Restart of the JIT compilers after they were stopped

Configuration	enabled
default	true
profiling	true

Field	Type	Description
freedMemory	int: bytes	Freed Memory
codeCacheMaxCapacity	ulong: bytes	Code Cache Maximum Capacity

Compilation

default profiling startTime duration eventThread 11 17 21 23 24

Category: Java Virtual Machine / Compiler

Results of method compilation attempts

Configuration	enabled	threshold
default	true	1000 ms
profiling	true	100 ms

Field	Type	Description
compileId	uint	Compilation Identifier
compiler	CompilerType 14+	Compiler Consider contributing a description to jfreventcollector.
method	Method	Method Consider contributing a description to jfreventcollector.
compileLevel	ushort	Compilation Level
succeded	boolean	Succeeded
isOsr	boolean	On Stack Replacement
codeSize	ulong: bytes	Compiled Code Size
inlinedBytes	ulong: bytes	Inlined Code Size

Examples 3

codeSize	ulong: bytes	7112
compileId	uint	6538
compileLevel	ushort	4
compiler	CompilerType	c2
inlinedBytes	ulong: bytes	160
isOsr	boolean	false
method	Method
descriptor	string	()V
hidden	boolean	false
modifiers	int	17
name	string	run
type	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	false
modifiers	int	49
name	string	scala/concurrent/impl/Promise$Transformation
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	scala/concurrent/impl
startTime	long: millis	11664503083
succeded	boolean	true

codeSize	ulong: bytes	16088
compileId	uint	16348
compileLevel	ushort	4
compiler	CompilerType	c2
inlinedBytes	ulong: bytes	2123
isOsr	boolean	false
method	Method
descriptor	string	(Lio/netty/handler/codec/http/HttpHeaders;Lcom/twitter/finagle/http/HeaderMap;)V
hidden	boolean	false
modifiers	int	1
name	string	writeNettyHeadersToFinagle
type	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	false
modifiers	int	33
name	string	com/twitter/finagle/netty4/http/Bijections$netty$
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	com/twitter/finagle/netty4/http
startTime	long: millis	34328890000
succeded	boolean	true

codeSize	ulong: bytes	11616
compileId	uint	15474
compileLevel	ushort	4
compiler	CompilerType	c2
inlinedBytes	ulong: bytes	1651
isOsr	boolean	false
method	Method
descriptor	string	(Lcom/twitter/util/Try;)Z
hidden	boolean	false
modifiers	int	17
name	string	updateIfEmpty
type	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	false
modifiers	int	33
name	string	com/twitter/util/Promise
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	com/twitter/util
startTime	long: millis	37050561167
succeded	boolean	true

CompilerPhase

default profiling startTime duration eventThread 11 17 21 23 24

Category: Java Virtual Machine / Compiler

Describes various phases of the compilation process like inlining or string optimization related phases

Configuration	enabled	threshold
default	true	60 s
profiling	true	10 s

Field	Type	Description
phase	CompilerPhaseType	Compile Phase
compileId	uint	Compilation Identifier
phaseLevel	ushort	Phase Level

CompilationFailure

profiling startTime eventThread 11 17 21 23 24

Category: Java Virtual Machine / Compiler

In case a JIT compilation failed, a compilation failure is triggered, reporting the reason

Configuration	enabled
default	false
profiling	true

Field	Type	Description
failureMessage	string	Failure Message
compileId	uint	Compilation Identifier

Examples 3

compileId	uint	22930
failureMessage	string	concurrent class loading
startTime	long: millis	74091028458

compileId	uint	23630
failureMessage	string	concurrent class loading
startTime	long: millis	58021071125

compileId	uint	23245
failureMessage	string	concurrent class loading
startTime	long: millis	82998780708

CompilerInlining

startTime eventThread 11 17 21 23 24

Category: Java Virtual Machine / Compiler / Optimization

Describes the result of a method inlining attempt

Configuration	enabled
default	false
profiling	false

Field	Type	Description
compileId	uint	Compilation Identifier
caller	Method	Caller Method
callee	CalleeMethod struct	Callee Method
succeeded	boolean	Succeeded
message	string	Message
bci	int	Bytecode Index

Examples 3

bci	int	150
callee	CalleeMethod
descriptor	string	(B)V
name	string	putUncheckedByte
type	string	jdk/jfr/internal/event/EventWriter
caller	Method
descriptor	string	(J)V
hidden	boolean	false
modifiers	int	2
name	string	putUncheckedLong
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	jdk/jfr/internal/event/EventWriter
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/jdk.jfr
name	string	jdk.jfr
version	string	21.0.1
name	string	jdk/jfr/internal/event
compileId	uint	1446
message	string	callee uses too much stack
startTime	long: millis	361744875
succeeded	boolean	false

bci	int	16
callee	CalleeMethod
descriptor	string	()V
name	string	<init>
type	string	java/lang/StringBuilder
caller	Method
descriptor	string	(IF)V
hidden	boolean	false
modifiers	int	1
name	string	<init>
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/HashMap
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util
compileId	uint	1455
message	string	inline
startTime	long: millis	414338083
succeeded	boolean	true

bci	int	196
callee	CalleeMethod
descriptor	string	(B)V
name	string	putUncheckedByte
type	string	jdk/jfr/internal/event/EventWriter
caller	Method
descriptor	string	(J)V
hidden	boolean	false
modifiers	int	2
name	string	putUncheckedLong
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	jdk/jfr/internal/event/EventWriter
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/jdk.jfr
name	string	jdk.jfr
version	string	21.0.1
name	string	jdk/jfr/internal/event
compileId	uint	1496
message	string	callee uses too much stack
startTime	long: millis	671266709
succeeded	boolean	false

Deoptimization

default profiling startTime eventThread stackTrace 14 17 21 23 24

Category: Java Virtual Machine / Compiler

Describes the detection of an uncommon situation in a compiled method which may lead to deoptimization of the method

Configuration	enabled	stackTrace
default	true	false
profiling	true	true

Field	Type	Description
compileId	uint	Compilation Identifier
compiler	CompilerType	Compiler Consider contributing a description to jfreventcollector.
method	Method	Method Consider contributing a description to jfreventcollector.
lineNumber	int	Line Number
bci	int	Bytecode Index
instruction	Bytecode	Instruction Consider contributing a description to jfreventcollector.
reason	DeoptimizationReason	Reason Consider contributing a description to jfreventcollector.
action	DeoptimizationAction	Action Consider contributing a description to jfreventcollector.

Examples 3

action	DeoptimizationAction	maybe_recompile
bci	int	5
compileId	uint	3090
compiler	CompilerType	c2
instruction	Bytecode	invokeinterface
lineNumber	int	164
method	Method
descriptor	string	(J)V
hidden	boolean	false
modifiers	int	1
name	string	begin
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/stream/ReduceOps$3ReducingSink
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/stream
reason	DeoptimizationReason	class_check
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	5
lineNumber	int	164
method	Method
descriptor	string	(J)V
hidden	boolean	false
modifiers	int	1
name	string	begin
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/stream/ReduceOps$3ReducingSink
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/stream
type	FrameType	JIT compiled
		…
truncated	boolean	false
startTime	long: millis	1829953708

action	DeoptimizationAction	maybe_recompile
bci	int	242
compileId	uint	2128
compiler	CompilerType	c2
instruction	Bytecode	invokevirtual
lineNumber	int	1039
method	Method
descriptor	string	(Ljava/lang/Object;Ljava/lang/Object;Z)Ljava/lang/Object;
hidden	boolean	false
modifiers	int	16
name	string	putVal
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/concurrent/ConcurrentHashMap
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/concurrent
reason	DeoptimizationReason	class_check
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	242
lineNumber	int	1039
method	Method
descriptor	string	(Ljava/lang/Object;Ljava/lang/Object;Z)Ljava/lang/Object;
hidden	boolean	false
modifiers	int	16
name	string	putVal
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/concurrent/ConcurrentHashMap
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/concurrent
type	FrameType	JIT compiled
		…
truncated	boolean	false
startTime	long: millis	2032711125

action	DeoptimizationAction	reinterpret
bci	int	13
compileId	uint	3007
compiler	CompilerType	c2
instruction	Bytecode	ifnonnull
lineNumber	int	592
method	Method
descriptor	string	(Ljava/lang/Object;Ljava/util/function/Function;)Ljava/lang/Object;
hidden	boolean	false
modifiers	int	1
name	string	computeIfAbsent
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/TreeMap
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util
reason	DeoptimizationReason	unstable_if
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	13
lineNumber	int	592
method	Method
descriptor	string	(Ljava/lang/Object;Ljava/util/function/Function;)Ljava/lang/Object;
hidden	boolean	false
modifiers	int	1
name	string	computeIfAbsent
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/TreeMap
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util
type	FrameType	Inlined
		…
truncated	boolean	false
startTime	long: millis	1821054333

CompilerStatistics

default profiling startTime every chunk 11 17 21 23 24

Category: Java Virtual Machine / Compiler

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	1000 ms
profiling	true	1000 ms

Field	Type	Description
compileCount	int	Compiled Methods
bailoutCount	int	Bailouts
invalidatedCount	int	Invalidated Compilations
osrCompileCount	int	OSR Compilations
standardCompileCount	int	Standard Compilations
osrBytesCompiled	ulong: bytes	OSR Bytes Compiled
standardBytesCompiled	ulong: bytes	Standard Bytes Compiled
nmethodsSize	ulong: bytes	Compilation Resulting Size
nmethodCodeSize	ulong: bytes	Compilation Resulting Code Size
peakTimeSpent	long: millis	Peak Time
totalTimeSpent	long: millis	Total time

Examples 3

bailoutCount	int	2
compileCount	int	6434
invalidatedCount	int	0
nmethodCodeSize	ulong: bytes	7923288
nmethodsSize	ulong: bytes	12405648
osrBytesCompiled	ulong: bytes	0
osrCompileCount	int	59
peakTimeSpent	long: millis	1099
standardBytesCompiled	ulong: bytes	0
standardCompileCount	int	6375
startTime	long: millis	22893174333
totalTimeSpent	long: millis	25503

bailoutCount	int	2
compileCount	int	17010
invalidatedCount	int	0
nmethodCodeSize	ulong: bytes	22346872
nmethodsSize	ulong: bytes	34301280
osrBytesCompiled	ulong: bytes	0
osrCompileCount	int	128
peakTimeSpent	long: millis	1103
standardBytesCompiled	ulong: bytes	0
standardCompileCount	int	16882
startTime	long: millis	40757657084
totalTimeSpent	long: millis	55360

bailoutCount	int	4
compileCount	int	29592
invalidatedCount	int	0
nmethodCodeSize	ulong: bytes	38505448
nmethodsSize	ulong: bytes	59296168
osrBytesCompiled	ulong: bytes	0
osrCompileCount	int	225
peakTimeSpent	long: millis	953
standardBytesCompiled	ulong: bytes	0
standardCompileCount	int	29367
startTime	long: millis	79065169583
totalTimeSpent	long: millis	57018

CompilerConfiguration

default profiling startTime end of every chunk 11 17 21 23 24

Category: Java Virtual Machine / Compiler

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
threadCount	int	Thread Count
tieredCompilation	boolean	Tiered Compilation

Examples 3

startTime	long: millis	78960104208
threadCount	int	4
tieredCompilation	boolean	true

startTime	long: millis	676032042
threadCount	int	4
tieredCompilation	boolean	true

startTime	long: millis	40031136208
threadCount	int	4
tieredCompilation	boolean	true

JVM: Diagnostics

SyncOnValueBasedClass

experimental default profiling startTime eventThread stackTrace 16 17 21 23 24

Category: Java Virtual Machine / Diagnostics

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	stackTrace
default	true	true
profiling	true	true

Field	Type	Description
valueBasedClass	Class	Value Based Class Consider contributing a description to jfreventcollector.

HeapDump

default profiling startTime duration eventThread stackTrace 15 17 21 23 24

Category: Java Virtual Machine / Diagnostics

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	stackTrace	threshold
default	true	true	0 ns
profiling	true	true	0 ns

Field	Type	Description
destination	string	Destination
size	long	Size
gcBeforeDump	boolean	GC Before Dump
onOutOfMemoryError	boolean	On Out of Memory Error

JVM: Flag

IntFlagChanged

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled
default	true
profiling	true

Field	Type	Description
name	string	Name
oldValue	int	Old Value
newValue	int	New Value
origin	FlagValueOrigin	Origin Consider contributing a description to jfreventcollector.

UnsignedIntFlagChanged

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled
default	true
profiling	true

Field	Type	Description
name	string	Name
oldValue	uint	Old Value
newValue	uint	New Value
origin	FlagValueOrigin	Origin Consider contributing a description to jfreventcollector.

LongFlagChanged

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled
default	true
profiling	true

Field	Type	Description
name	string	Name
oldValue	long	Old Value
newValue	long	New Value
origin	FlagValueOrigin	Origin Consider contributing a description to jfreventcollector.

UnsignedLongFlagChanged

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled
default	true
profiling	true

Field	Type	Description
name	string	Name
oldValue	ulong	Old Value
newValue	ulong	New Value
origin	FlagValueOrigin	Origin Consider contributing a description to jfreventcollector.

DoubleFlagChanged

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled
default	true
profiling	true

Field	Type	Description
name	string	Name
oldValue	double	Old Value
newValue	double	New Value
origin	FlagValueOrigin	Origin Consider contributing a description to jfreventcollector.

BooleanFlagChanged

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled
default	true
profiling	true

Field	Type	Description
name	string	Name
oldValue	boolean	Old Value
newValue	boolean	New Value
origin	FlagValueOrigin	Origin Consider contributing a description to jfreventcollector.

StringFlagChanged

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled
default	true
profiling	true

Field	Type	Description
name	string	Name
oldValue	string	Old Value
newValue	string	New Value
origin	FlagValueOrigin	Origin Consider contributing a description to jfreventcollector.

IntFlag

default profiling startTime duration end of every chunk 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
name	string	Name
value	int	Value
origin	FlagValueOrigin	Origin Consider contributing a description to jfreventcollector.

Examples 3

name	string	CompilerThreadPriority
origin	FlagValueOrigin	Default
startTime	long: millis	30519911125
value	int	-1

name	string	PerfDataMemorySize
origin	FlagValueOrigin	Default
startTime	long: millis	22150023250
value	int	32768

name	string	JavaPriority10_To_OSPriority
origin	FlagValueOrigin	Default
startTime	long: millis	30586822708
value	int	-1

UnsignedIntFlag

default profiling startTime duration end of every chunk 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
name	string	Name
value	uint	Value
origin	FlagValueOrigin	Origin Consider contributing a description to jfreventcollector.

Examples 3

name	string	UseSVE
origin	FlagValueOrigin	Default
startTime	long: millis	52082153208
value	uint	0

name	string	G1ConcRefinementThreads
origin	FlagValueOrigin	Ergonomic
startTime	long: millis	676055292
value	uint	8

name	string	MarkSweepAlwaysCompactCount
origin	FlagValueOrigin	Default
startTime	long: millis	75087036792
value	uint	4

LongFlag

default profiling startTime duration end of every chunk 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
name	string	Name
value	long	Value
origin	FlagValueOrigin	Origin Consider contributing a description to jfreventcollector.

Examples 3

name	string	ValueMapMaxLoopSize
origin	FlagValueOrigin	Default
startTime	long: millis	676073417
value	long	8

name	string	MultiArrayExpandLimit
origin	FlagValueOrigin	Default
startTime	long: millis	423469833
value	long	6

name	string	C1MaxInlineSize
origin	FlagValueOrigin	Default
startTime	long: millis	364805083
value	long	35

UnsignedLongFlag

default profiling startTime duration end of every chunk 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
name	string	Name
value	ulong	Value
origin	FlagValueOrigin	Origin Consider contributing a description to jfreventcollector.

Examples 3

name	string	NUMAInterleaveGranularity
origin	FlagValueOrigin	Default
startTime	long: millis	364828500
value	ulong	2097152

name	string	StartAggressiveSweepingAt
origin	FlagValueOrigin	Default
startTime	long: millis	676109417
value	ulong	10

name	string	MaxVirtMemFraction
origin	FlagValueOrigin	Default
startTime	long: millis	423580833
value	ulong	2

DoubleFlag

default profiling startTime duration end of every chunk 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
name	string	Name
value	double	Value
origin	FlagValueOrigin	Origin Consider contributing a description to jfreventcollector.

Examples 3

name	string	ZCollectionInterval
origin	FlagValueOrigin	Default
startTime	long: millis	15845390458
value	double	0.0

name	string	ZCollectionInterval
origin	FlagValueOrigin	Default
startTime	long: millis	60345456583
value	double	0.0

name	string	G1PeriodicGCSystemLoadThreshold
origin	FlagValueOrigin	Default
startTime	long: millis	22150057667
value	double	0.0

BooleanFlag

default profiling startTime duration end of every chunk 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
name	string	Name
value	boolean	Value
origin	FlagValueOrigin	Origin Consider contributing a description to jfreventcollector.

Examples 3

name	string	TraceTraps
origin	FlagValueOrigin	Default
startTime	long: millis	676141750
value	boolean	false

name	string	PrintIR0
origin	FlagValueOrigin	Default
startTime	long: millis	423596708
value	boolean	false

name	string	C1ProfileCheckcasts
origin	FlagValueOrigin	Default
startTime	long: millis	364843083
value	boolean	true

StringFlag

default profiling startTime duration end of every chunk 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
name	string	Name
value	string	Value
origin	FlagValueOrigin	Origin Consider contributing a description to jfreventcollector.

Examples 3

name	string	OnOutOfMemoryError
origin	FlagValueOrigin	Default
startTime	long: millis	30586898792
value	string

name	string	DeoptimizeOnlyAt
origin	FlagValueOrigin	Default
startTime	long: millis	40031307125
value	string

name	string	StartFlightRecording
origin	FlagValueOrigin	Command line
startTime	long: millis	676243792
value	string	filename=[...]/code/experiments/jfreventcollector/jfr/sample_UseG1GC.jfr,settings=[...]/code/experiments/jfreventcollector/.cache/jfc.jfc

JVM: GC: Collector

GarbageCollection

default profiling startTime duration 11 17 21 23 24 graal vm

Category: Java Virtual Machine / GC / Collector

Garbage collection performed by the JVM

Configuration	enabled	threshold
default	true	0 ms
profiling	true	0 ms

Field	Type	Description
gcId	uint	GC Identifier
name	GCName	Name The name of the Garbage Collector
cause	GCCause	Cause The reason for triggering this Garbage Collection
sumOfPauses	Tickspan	Sum of Pauses Sum of all the times in which Java execution was paused during the garbage collection
longestPause	Tickspan	Longest Pause Longest individual pause during the garbage collection

Examples 3

cause	GCCause	Allocation Failure
gcId	uint	48
longestPause	Tickspan	626709
name	GCName	ParallelScavenge
startTime	long: millis	28324881833
sumOfPauses	Tickspan	626709

cause	GCCause	Allocation Failure
gcId	uint	54
longestPause	Tickspan	747084
name	GCName	DefNew
startTime	long: millis	5489961333
sumOfPauses	Tickspan	747084

cause	GCCause	G1 Evacuation Pause
gcId	uint	36
longestPause	Tickspan	21154750
name	GCName	G1New
startTime	long: millis	9097943542
sumOfPauses	Tickspan	21154750

SystemGC

default profiling startTime duration eventThread stackTrace 17 21 23 24

Category: Java Virtual Machine / GC / Collector

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	stackTrace	threshold
default	true	true	0 ms
profiling	true	true	0 ms

Field	Type	Description
invokedConcurrent	boolean	Invoked Concurrent

Examples 3

invokedConcurrent	boolean	false
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	()V
hidden	boolean	false
modifiers	int	257
name	string	gc
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/lang/Runtime
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	32283999125

invokedConcurrent	boolean	false
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	()V
hidden	boolean	false
modifiers	int	257
name	string	gc
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/lang/Runtime
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	51429326792

invokedConcurrent	boolean	false
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	()V
hidden	boolean	false
modifiers	int	257
name	string	gc
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/lang/Runtime
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	64382500042

ParallelOldGarbageCollection

default profiling startTime duration 11 17 21 23 24

Category: Java Virtual Machine / GC / Collector

Appearing in: ParallelGC

Missing in: G1GC, SerialGC, ShenandoahGC, ZGC

Extra information specific to Parallel Old Garbage Collections

Configuration	enabled	threshold
default	true	0 ms
profiling	true	0 ms

Field	Type	Description
gcId	uint	GC Identifier
densePrefix	ulong: address	Dense Prefix The address of the dense prefix, used when compacting

Examples 1

ParallelGC

densePrefix	ulong: address	30160715776
gcId	uint	114
startTime	long: millis	78961539167

YoungGarbageCollection

default profiling startTime duration 11 17 21 23 24

Category: Java Virtual Machine / GC / Collector

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

Extra information specific to Young Garbage Collections

Configuration	enabled	threshold
default	true	0 ms
profiling	true	0 ms

Field	Type	Description
gcId	uint	GC Identifier
tenuringThreshold	uint	Tenuring Threshold

Examples 3

gcId	uint	13
startTime	long: millis	2072697250
tenuringThreshold	uint	1

gcId	uint	91
startTime	long: millis	31957969042
tenuringThreshold	uint	15

gcId	uint	81
startTime	long: millis	12475301917
tenuringThreshold	uint	1

OldGarbageCollection

default profiling startTime duration 11 17 21 23 24

Category: Java Virtual Machine / GC / Collector

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

Extra information specific to Old Garbage Collections

Configuration	enabled	threshold
default	true	0 ms
profiling	true	0 ms

Field	Type	Description
gcId	uint	GC Identifier

Examples 3

gcId	uint	168
startTime	long: millis	52449403792

gcId	uint	249
startTime	long: millis	52082303708

gcId	uint	121
startTime	long: millis	93759582875

G1GarbageCollection

default profiling startTime duration 11 17 21 23 24

Category: Java Virtual Machine / GC / Collector

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Extra information specific to G1 Young Garbage Collections

Configuration	enabled	threshold
default	true	0 ms
profiling	true	0 ms

Field	Type	Description
gcId	uint	GC Identifier
type	G1YCType	Type Consider contributing a description to jfreventcollector.

Examples 1

G1GC

gcId	uint	9
startTime	long: millis	1605757334
type	G1YCType	Mixed

JVM: GC: Configuration

GCConfiguration

default profiling startTime duration end of every chunk 11 17 21 23 24

Category: Java Virtual Machine / GC / Configuration

The configuration of the garbage collector

Configuration	enabled	period
default	true	everyChunk
profiling	true	everyChunk

Field	Type	Description
youngCollector	GCName	Young Garbage Collector The garbage collector used for the young generation
oldCollector	GCName	Old Garbage Collector The garbage collector used for the old generation
parallelGCThreads	uint	Parallel GC Threads Number of parallel threads to use for garbage collection
concurrentGCThreads	uint	Concurrent GC Threads Number of concurrent threads to use for garbage collection
usesDynamicGCThreads	boolean	Uses Dynamic GC Threads Whether a dynamic number of GC threads are used or not
isExplicitGCConcurrent	boolean	Concurrent Explicit GC Whether System.gc() is concurrent or not
isExplicitGCDisabled	boolean	Disabled Explicit GC Whether System.gc() will cause a garbage collection or not
pauseTarget	long: millis	Pause Target Target for GC pauses
gcTimeRatio	uint	GC Time Ratio Target for runtime vs garbage collection time

Examples 3

concurrentGCThreads	uint	0
gcTimeRatio	uint	99
isExplicitGCConcurrent	boolean	false
isExplicitGCDisabled	boolean	false
oldCollector	GCName	SerialOld
parallelGCThreads	uint	0
pauseTarget	long: millis	-9223372036854775808
startTime	long: millis	52241832208
usesDynamicGCThreads	boolean	true
youngCollector	GCName	DefNew

concurrentGCThreads	uint	0
gcTimeRatio	uint	99
isExplicitGCConcurrent	boolean	false
isExplicitGCDisabled	boolean	false
oldCollector	GCName	ParallelOld
parallelGCThreads	uint	8
pauseTarget	long: millis	-9223372036854775808
startTime	long: millis	94256843625
usesDynamicGCThreads	boolean	true
youngCollector	GCName	ParallelScavenge

concurrentGCThreads	uint	2
gcTimeRatio	uint	12
isExplicitGCConcurrent	boolean	false
isExplicitGCDisabled	boolean	false
oldCollector	GCName	G1Old
parallelGCThreads	uint	8
pauseTarget	long: millis	-9223372036854775808
startTime	long: millis	50890273459
usesDynamicGCThreads	boolean	true
youngCollector	GCName	G1New

GCSurvivorConfiguration

default profiling startTime duration end of every chunk 11 17 21 23 24

Category: Java Virtual Machine / GC / Configuration

The configuration of the survivors of garbage collection

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
maxTenuringThreshold	ubyte	Maximum Tenuring Threshold Upper limit for the age of how old objects to keep in the survivor area
initialTenuringThreshold	ubyte	Initial Tenuring Threshold Initial age limit for how old objects to keep in survivor area

Examples 3

initialTenuringThreshold	ubyte	7
maxTenuringThreshold	ubyte	15
startTime	long: millis	75290926875

initialTenuringThreshold	ubyte	7
maxTenuringThreshold	ubyte	15
startTime	long: millis	39413197708

initialTenuringThreshold	ubyte	7
maxTenuringThreshold	ubyte	15
startTime	long: millis	52241833167

GCTLABConfiguration

default profiling startTime duration end of every chunk 11 17 21 23 24

Category: Java Virtual Machine / GC / Configuration

The configuration of the Thread Local Allocation Buffers (TLABs)

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
usesTLABs	boolean	TLABs Used If Thread Local Allocation Buffers (TLABs) are in use
minTLABSize	ulong: bytes	Minimum TLAB Size
tlabRefillWasteLimit	ulong: bytes	TLAB Refill Waste Limit

Examples 3

minTLABSize	ulong: bytes	2048
startTime	long: millis	378404667
tlabRefillWasteLimit	ulong: bytes	64
usesTLABs	boolean	true

minTLABSize	ulong: bytes	2048
startTime	long: millis	436497958
tlabRefillWasteLimit	ulong: bytes	64
usesTLABs	boolean	true

minTLABSize	ulong: bytes	2048
startTime	long: millis	75290927459
tlabRefillWasteLimit	ulong: bytes	64
usesTLABs	boolean	true

GCHeapConfiguration

default profiling startTime duration end of every chunk 11 17 21 23 24

Category: Java Virtual Machine / GC / Configuration

The configuration of the garbage collected heap

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
minSize	ulong: bytes	Minimum Heap Size
maxSize	ulong: bytes	Maximum Heap Size
initialSize	ulong: bytes	Initial Heap Size
usesCompressedOops	boolean	If Compressed Oops Are Used If compressed Oops (Ordinary Object Pointers) are enabled
compressedOopsMode	NarrowOopMode	Compressed Oops Mode The kind of compressed oops being used
objectAlignment	ulong: bytes	Object Alignment Object alignment (in bytes) on the heap
heapAddressBits	ubyte	Heap Address Size Heap Address Size (in bits)

Examples 3

compressedOopsMode	NarrowOopMode	Zero based
heapAddressBits	ubyte	32
initialSize	ulong: bytes	268435456
maxSize	ulong: bytes	4294967296
minSize	ulong: bytes	8388608
objectAlignment	ulong: bytes	8
startTime	long: millis	75290927875
usesCompressedOops	boolean	true

compressedOopsMode	NarrowOopMode	Zero based
heapAddressBits	ubyte	32
initialSize	ulong: bytes	268435456
maxSize	ulong: bytes	4294967296
minSize	ulong: bytes	8388608
objectAlignment	ulong: bytes	8
startTime	long: millis	18250637583
usesCompressedOops	boolean	true

compressedOopsMode	NarrowOopMode	Zero based
heapAddressBits	ubyte	32
initialSize	ulong: bytes	268435456
maxSize	ulong: bytes	4294967296
minSize	ulong: bytes	8388608
objectAlignment	ulong: bytes	8
startTime	long: millis	30690534667
usesCompressedOops	boolean	true

YoungGenerationConfiguration

default profiling startTime duration end of every chunk 11 17 21 23 24

Category: Java Virtual Machine / GC / Configuration

The configuration of the young generation of the garbage collected heap

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
minSize	ulong: bytes	Minimum Young Generation Size
maxSize	ulong: bytes	Maximum Young Generation Size
newRatio	uint	New Ratio The size of the young generation relative to the tenured generation

Examples 3

maxSize	ulong: bytes	1431633920
minSize	ulong: bytes	89456640
newRatio	uint	2
startTime	long: millis	16561213250

maxSize	ulong: bytes	1431306240
minSize	ulong: bytes	89128960
newRatio	uint	2
startTime	long: millis	93887425708

maxSize	ulong: bytes	2575302656
minSize	ulong: bytes	1363144
newRatio	uint	2
startTime	long: millis	13055587417

JVM: GC: Detailed

G1MMU

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled
default	true
profiling	true

Field	Type	Description
gcId	uint	GC Identifier
timeSlice	long: millis	Time Slice Time slice used to calculate MMU
gcTime	long: millis	GC Time Time stopped because of GC during last time slice
pauseTarget	long: millis	Pause Target Max time allowed to be spent on GC during last time slice

Examples 1

G1GC

gcId	uint	109
gcTime	long: millis	5
pauseTarget	long: millis	200
startTime	long: millis	39626396084
timeSlice	long: millis	201

EvacuationInformation

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled
default	true
profiling	true

Field	Type	Description
gcId	uint	GC Identifier
cSetRegions	uint	Collection Set Regions
cSetUsedBefore	ulong: bytes	Collection Set Before Memory usage before GC in the collection set regions
cSetUsedAfter	ulong: bytes	Collection Set After Memory usage after GC in the collection set regions
allocationRegions	uint	Allocation Regions Regions chosen as allocation regions during evacuation (includes survivors and old space regions)
allocationRegionsUsedBefore	ulong: bytes	Allocation Regions Before Memory usage before GC in allocation regions
allocationRegionsUsedAfter	ulong: bytes	Allocation Regions After Memory usage after GC in allocation regions
bytesCopied	ulong: bytes	Bytes Copied
regionsFreed	uint	Regions Freed

Examples 1

G1GC

allocationRegions	uint	7
allocationRegionsUsedAfter	ulong: bytes	12834336
allocationRegionsUsedBefore	ulong: bytes	0
bytesCopied	ulong: bytes	12834336
cSetRegions	uint	367
cSetUsedAfter	ulong: bytes	0
cSetUsedBefore	ulong: bytes	767858392
gcId	uint	76
regionsFreed	uint	367
startTime	long: millis	23687698667

ObjectCountAfterGC

startTime 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled
default	false
profiling	false

Field	Type	Description
gcId	uint	GC Identifier
objectClass	Class	Object Class Consider contributing a description to jfreventcollector.
count	long	Count
totalSize	ulong: bytes	Total Size

Examples 3

count	long	958
gcId	uint	1
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	0
name	string	[Ljava/lang/String;
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
startTime	long: millis	865943958
totalSize	ulong: bytes	36664

count	long	45
gcId	uint	1
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	0
name	string	[Ljava/util/concurrent/ConcurrentHashMap$Node;
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/concurrent
startTime	long: millis	431274583
totalSize	ulong: bytes	27728

count	long	192
gcId	uint	7
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	0
name	string	[I
package	Package	null
startTime	long: millis	1447281875
totalSize	ulong: bytes	112224

G1EvacuationYoungStatistics

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Memory related evacuation statistics during GC for the young generation

Configuration	enabled
default	true
profiling	true

Field	Type	Description
statistics	G1EvacuationStatistics struct	Evacuation Statistics

Examples 1

G1GC

startTime	long: millis	9995446459
statistics	G1EvacuationStatistics
allocated	ulong: bytes	44040192
directAllocated	ulong: bytes	0
failureUsed	ulong: bytes	0
failureWaste	ulong: bytes	0
gcId	uint	39
numDirectAllocated	ulong	5
numPlabsFilled	ulong	7504122885671534260
regionEndWaste	ulong: bytes	0
regionsRefilled	uint	21
undoWaste	ulong: bytes	0
used	ulong: bytes	44038320
wasted	ulong: bytes	1872

G1EvacuationOldStatistics

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Memory related evacuation statistics during GC for the old generation

Configuration	enabled
default	true
profiling	true

Field	Type	Description
statistics	G1EvacuationStatistics struct	Evacuation Statistics

Examples 1

G1GC

startTime	long: millis	2325131709
statistics	G1EvacuationStatistics
allocated	ulong: bytes	0
directAllocated	ulong: bytes	0
failureUsed	ulong: bytes	0
failureWaste	ulong: bytes	0
gcId	uint	17
numDirectAllocated	ulong	6147041496
numPlabsFilled	ulong	0
regionEndWaste	ulong: bytes	0
regionsRefilled	uint	0
undoWaste	ulong: bytes	0
used	ulong: bytes	0
wasted	ulong: bytes	0

G1BasicIHOP

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Basic statistics related to current IHOP calculation

Configuration	enabled
default	true
profiling	true

Field	Type	Description
gcId	uint	GC Identifier
threshold	ulong: bytes	Current IHOP Threshold Current IHOP threshold
thresholdPercentage	float: percentage	Current IHOP Threshold Current IHOP threshold in percent of old generation
targetOccupancy	ulong: bytes	Target Occupancy Target old generation occupancy to reach at the start of mixed GC
currentOccupancy	ulong: bytes	Current Occupancy Current old generation occupancy
recentMutatorAllocationSize	ulong: bytes	Recent Mutator Allocation Size Mutator allocation during mutator operation in the most recent interval
recentMutatorDuration	long: millis	Recent Mutator Duration Time the mutator ran in the most recent interval
recentAllocationRate	double: bytes-per-second	Recent Allocation Rate Allocation rate of the mutator in the most recent interval in bytes/second
lastMarkingDuration	long: millis	Last Marking Duration Last time from the end of the last concurrent start to the first mixed GC

Examples 1

G1GC

currentOccupancy	ulong: bytes	777327304
gcId	uint	120
lastMarkingDuration	long: millis	880
recentAllocationRate	double: bytes-per-second	6.647098700594988E7
recentMutatorAllocationSize	ulong: bytes	152043520
recentMutatorDuration	long: millis	2287
startTime	long: millis	43224599250
targetOccupancy	ulong: bytes	1684013056
threshold	ulong: bytes	757805875
thresholdPercentage	float: percentage	0.45

G1AdaptiveIHOP

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Statistics related to current adaptive IHOP calculation

Configuration	enabled
default	true
profiling	true

Field	Type	Description
gcId	uint	GC Identifier
threshold	ulong: bytes	Threshold Current IHOP Threshold
thresholdPercentage	float: percentage	Threshold Current IHOP threshold in percent of the internal target occupancy
ihopTargetOccupancy	ulong: bytes	IHOP Target Occupancy Internal target old generation occupancy to reach at the start of mixed GC
currentOccupancy	ulong: bytes	Current Occupancy Current old generation occupancy
additionalBufferSize	ulong: bytes	Additional Buffer Additional buffer size
predictedAllocationRate	double: bytes-per-second	Predicted Allocation Rate Current predicted allocation rate for the mutator in bytes/second
predictedMarkingDuration	long: millis	Predicted Marking Duration Current predicted time from the end of the last concurrent start to the first mixed GC
predictionActive	boolean	Prediction Active Indicates whether the adaptive IHOP prediction is active

Examples 1

G1GC

additionalBufferSize	ulong: bytes	390070272
currentOccupancy	ulong: bytes	186580592
gcId	uint	61
ihopTargetOccupancy	ulong: bytes	617611264
predictedAllocationRate	double: bytes-per-second	1.9214995359726005E9
predictedMarkingDuration	long: millis	338
predictionActive	boolean	false
startTime	long: millis	21815314459
threshold	ulong: bytes	292552704
thresholdPercentage	float: percentage	0.47368422

PromoteObjectInNewPLAB

profiling startTime eventThread 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC

Missing in: SerialGC, ShenandoahGC, ZGC

Object survived scavenge and was copied to a new Promotion Local Allocation Buffer (PLAB). Supported GCs are Parallel Scavange, G1 and CMS with Parallel New. Due to promotion being done in parallel an object might be reported multiple times as the GC threads race to copy all objects.

Configuration	enabled
default	false
profiling	true

Field	Type	Description
gcId	uint	GC Identifier Identifier signifying GC during which the object was promoted
objectClass	Class	Object Class Class of promoted object
objectSize	ulong: bytes	Object Size Size of promoted object
tenuringAge	uint	Object Tenuring Age Tenuring age of a surviving object before being copied. The tenuring age of an object is a value between 0-15 and is incremented each scavange the object survives. Newly allocated objects have tenuring age 0.
tenured	boolean	Tenured True if object was promoted to Old space, otherwise the object was aged and copied to a Survivor space
plabSize	ulong: bytes	PLAB Size Size of the allocated PLAB to which the object was copied

Examples 2

ParallelGC
G1GC

gcId	uint	5
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	0
name	string	[B
package	Package	null
objectSize	ulong: bytes	24
plabSize	ulong: bytes	32752
startTime	long: millis	1161659417
tenured	boolean	false
tenuringAge	uint	1

gcId	uint	4
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/lang/Object
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
objectSize	ulong: bytes	16
plabSize	ulong: bytes	56672
startTime	long: millis	977531292
tenured	boolean	false
tenuringAge	uint	0

PromoteObjectOutsidePLAB

profiling startTime eventThread 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC

Missing in: SerialGC, ShenandoahGC, ZGC

Object survived scavenge and was copied directly to the heap. Supported GCs are Parallel Scavange, G1 and CMS with Parallel New. Due to promotion being done in parallel an object might be reported multiple times as the GC threads race to copy all objects.

Configuration	enabled
default	false
profiling	true

Field	Type	Description
gcId	uint	GC Identifier Identifier signifying GC during which the object was promoted
objectClass	Class	Object Class Class of promoted object
objectSize	ulong: bytes	Object Size Size of promoted object
tenuringAge	uint	Object Tenuring Age Tenuring age of a surviving object before being copied. The tenuring age of an object is a value between 0-15 and is incremented each scavange the object survives. Newly allocated objects have tenuring age 0.
tenured	boolean	Tenured True if object was promoted to Old space, otherwise the object was aged and copied to a Survivor space

Examples 2

G1GC
ParallelGC

gcId	uint	58
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	0
name	string	[Ljava/lang/Object;
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
objectSize	ulong: bytes	50352
startTime	long: millis	21580228167
tenured	boolean	false
tenuringAge	uint	0

gcId	uint	6
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	0
name	string	[Ljava/lang/Object;
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
objectSize	ulong: bytes	65552
startTime	long: millis	1246384375
tenured	boolean	false
tenuringAge	uint	0

PromotionFailed

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Promotion of an object failed

Configuration	enabled
default	true
profiling	true

Field	Type	Description
gcId	uint	GC Identifier
promotionFailed	CopyFailed struct	Promotion Failed Data
thread	Thread	Running thread

EvacuationFailed

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Evacuation of an object failed

Configuration	enabled
default	true
profiling	true

Field	Type	Description
gcId	uint	GC Identifier
evacuationFailed	CopyFailed struct	Evacuation Failed Data

ConcurrentModeFailure

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Concurrent Mode failed

Configuration	enabled
default	true
profiling	true

Field	Type	Description
gcId	uint	GC Identifier

GCCPUTime

default profiling startTime 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

GC CPU Time information. Supported: G1GC, ParallelGC and SerialGC

Configuration	enabled
default	true
profiling	true

Field	Type	Description
gcId	uint	GC Identifier
userTime	ulong: nanos	User Time
systemTime	ulong: nanos	System Time
realTime	ulong: nanos	Real Time

Examples 3

gcId	uint	49
realTime	ulong: nanos	90000152
startTime	long: millis	16020848917
systemTime	ulong: nanos	30000000
userTime	ulong: nanos	500000000

gcId	uint	94
realTime	ulong: nanos	69999933
startTime	long: millis	15735632333
systemTime	ulong: nanos	0
userTime	ulong: nanos	59999999

gcId	uint	26
realTime	ulong: nanos	220000028
startTime	long: millis	16980481875
systemTime	ulong: nanos	209999999
userTime	ulong: nanos	309999999

AllocationRequiringGC

startTime eventThread stackTrace 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	stackTrace
default	false	true
profiling	false	true

Field	Type	Description
gcId	uint	Pending GC Identifier
size	ulong: bytes	Allocation Size

Examples 3

gcId	uint	101
size	ulong: bytes	56
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	5
lineNumber	int	69
method	Method
descriptor	string	(Ljava/util/Spliterator;Z)Ljava/util/stream/Stream;
hidden	boolean	false
modifiers	int	9
name	string	stream
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/util/stream/StreamSupport
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/stream
type	FrameType	Inlined
		…
truncated	boolean	true
startTime	long: millis	71227040375

gcId	uint	19
size	ulong: bytes	2048
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	1909
method	Method
descriptor	string	(ILjava/lang/Object;Ljava/lang/Object;Ljava/util/HashMap$Node;)Ljava/util/HashMap$Node;
hidden	boolean	false
modifiers	int	0
name	string	newNode
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/HashMap
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util
type	FrameType	Inlined
		…
truncated	boolean	false
startTime	long: millis	2468017875

gcId	uint	87
size	ulong: bytes	24
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	10
lineNumber	int	83
method	Method
descriptor	string	(Lscala/collection/immutable/RedBlackTree$Tree;)Lscala/collection/immutable/TreeMap;
hidden	boolean	false
modifiers	int	2
name	string	newMapOrSelf
type	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	false
modifiers	int	49
name	string	scala/collection/immutable/TreeMap
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	scala/collection/immutable
type	FrameType	Inlined
		…
truncated	boolean	false
startTime	long: millis	13957355375

TenuringDistribution

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, SerialGC

Missing in: ParallelGC, ShenandoahGC, ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled
default	true
profiling	true

Field	Type	Description
gcId	uint	GC Identifier
age	uint	Age
size	ulong: bytes	Size

Examples 2

G1GC
SerialGC

age	uint	11
gcId	uint	1
size	ulong: bytes	0
startTime	long: millis	690879834

age	uint	11
gcId	uint	17
size	ulong: bytes	0
startTime	long: millis	1795047750

G1HeapRegionTypeChange

startTime 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Information about a G1 heap region type change

Configuration	enabled
default	false
profiling	false

Field	Type	Description
index	uint	Index
from	G1HeapRegionType	From Consider contributing a description to jfreventcollector.
to	G1HeapRegionType	To Consider contributing a description to jfreventcollector.
start	ulong: address	Start
used	ulong: bytes	Used

Examples 1

G1GC

from	G1HeapRegionType	Free
index	uint	29
start	ulong: address	30125588480
startTime	long: millis	690146250
to	G1HeapRegionType	Free
used	ulong: bytes	0

ObjectCount

startTime every chunk 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	false	everyChunk
profiling	false	everyChunk

Field	Type	Description
gcId	uint	GC Identifier
objectClass	Class	Object Class Consider contributing a description to jfreventcollector.
count	long	Count
totalSize	ulong: bytes	Total Size

Examples 3

count	long	207454
gcId	uint	22
objectClass	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	false
modifiers	int	33
name	string	akka/actor/ActorCell
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	akka/actor
startTime	long: millis	9266401125
totalSize	ulong: bytes	18255952

count	long	199990
gcId	uint	34
objectClass	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	true
modifiers	int	4144
name	string	edu.rice.habanero.benchmarks.uct.UctAkkaActorBenchmark$NodeActor$$$Lambda+0x0000000800444b90/767881025
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	edu/rice/habanero/benchmarks/uct
startTime	long: millis	8979422834
totalSize	ulong: bytes	7999600

count	long	5794
gcId	uint	1
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/jar/Attributes
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/jar
startTime	long: millis	865943958
totalSize	ulong: bytes	92704

G1HeapRegionInformation

startTime duration every chunk 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Information about a specific heap region in the G1 GC

Configuration	enabled	period
default	false	everyChunk
profiling	false	everyChunk

Field	Type	Description
index	uint	Index
type	G1HeapRegionType	Type Consider contributing a description to jfreventcollector.
start	ulong: address	Start
used	ulong: bytes	Used

Examples 1

G1GC

index	uint	33
start	ulong: address	30133977088
startTime	long: millis	12822303584
type	G1HeapRegionType	Old
used	ulong: bytes	2097152

ZAllocationStall

default profiling startTime duration eventThread 15 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Time spent waiting for memory to become available

Configuration	enabled	threshold
default	true	0 ms
profiling	true	0 ms

Field	Type	Description
type	ZPageTypeType	Type Consider contributing a description to jfreventcollector.
size	ulong: bytes	Size

Examples 1

size	ulong: bytes	2097152
startTime	long: millis	25102007000
type	ZPageTypeType	Small

ZPageAllocation

default profiling startTime duration eventThread stackTrace 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Allocation of a ZPage

Configuration	enabled	stackTrace	threshold
default	true	true 15+	1 ms
profiling	true	true 15+	1 ms

Field	Type	Description
type	ZPageTypeType 15+	Type Consider contributing a description to jfreventcollector.
size	ulong: bytes 15+	Size
flushed	ulong: bytes 15+	Flushed
committed	ulong: bytes 15+	Committed
segments	uint 15+	Segments
nonBlocking	boolean	Non-blocking

Examples 1

committed	ulong: bytes	0
flushed	ulong: bytes	0
nonBlocking	boolean	false
segments	uint	1
size	ulong: bytes	2097152
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	5
lineNumber	int	153
method	Method
descriptor	string	(Ljava/lang/Object;)V
hidden	boolean	false
modifiers	int	0
name	string	linkLast
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/LinkedList
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util
type	FrameType	Inlined
		…
truncated	boolean	false
startTime	long: millis	15127121625
type	ZPageTypeType	Small

ZRelocationSet

default profiling startTime duration eventThread 15 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	threshold
default	true	0 ms
profiling	true	0 ms

Field	Type	Description
total	ulong: bytes	Total
empty	ulong: bytes	Empty
relocate	ulong: bytes 16+	Relocate

Examples 1

empty	ulong: bytes	0
relocate	ulong: bytes	3483048
startTime	long: millis	755952125
total	ulong: bytes	67108864

ZRelocationSetGroup

default profiling startTime duration eventThread 15 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	threshold
default	true	0 ms
profiling	true	0 ms

Field	Type	Description
type	ZPageTypeType	Type Consider contributing a description to jfreventcollector.
pages	ulong 17 until JDK 21	Pages
total	ulong: bytes	Total
empty	ulong: bytes	Empty
relocate	ulong: bytes 16+	Relocate

Examples 1

empty	ulong: bytes	778043392
relocate	ulong: bytes	1138680
startTime	long: millis	36947940041
total	ulong: bytes	985661440
type	ZPageTypeType	Small

ZStatisticsCounter

experimental startTime duration eventThread 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	threshold
default	false	0 ms
profiling	false	0 ms

Field	Type	Description
id	ZStatisticsCounterType	Id Consider contributing a description to jfreventcollector.
increment	ulong	Increment
value	ulong	Value

Examples 1

id	ZStatisticsCounterType	Allocation Rate
increment	ulong	2097152
startTime	long: millis	1047771833
value	ulong	92274688

ZStatisticsSampler

experimental startTime duration eventThread 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	threshold
default	false	0 ms
profiling	false	0 ms

Field	Type	Description
id	ZStatisticsSamplerType	Id Consider contributing a description to jfreventcollector.
value	ulong	Value

Examples 1

id	ZStatisticsSamplerType	Concurrent Roots ClassLoaderDataGraph
startTime	long: millis	331486208
value	ulong	625

ZThreadPhase

experimental startTime duration eventThread 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	threshold
default	false	0 ms
profiling	false	0 ms

Field	Type	Description
gcId	uint	GC Identifier
name	string	Name

Examples 1

gcId	uint	0
name	string	Concurrent Roots JavaThreads
startTime	long: millis	331553583

ZUncommit

default profiling startTime duration eventThread 15 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Uncommitting of memory

Configuration	enabled	threshold
default	true	0 ms
profiling	true	0 ms

Field	Type	Description
uncommitted	ulong: bytes	Uncommitted

ZUnmap

default profiling startTime duration eventThread 15 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Unmapping of memory

Configuration	enabled	threshold
default	true	0 ms
profiling	true	0 ms

Field	Type	Description
unmapped	ulong: bytes	Unmapped

Examples 1

startTime	long: millis	30472706291
unmapped	ulong: bytes	2097152

ShenandoahHeapRegionStateChange

startTime 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: ShenandoahGC

Missing in: G1GC, ParallelGC, SerialGC, ZGC

Information about a Shenandoah heap region state change

Configuration	enabled
default	false
profiling	false

Field	Type	Description
index	uint	Index
from	ShenandoahHeapRegionState	From Consider contributing a description to jfreventcollector.
to	ShenandoahHeapRegionState	To Consider contributing a description to jfreventcollector.
start	ulong: address	Start
used	ulong: bytes	Used

Examples 1

ShenandoahGC

from	ShenandoahHeapRegionState	Trash
index	uint	12
start	ulong: address	30089936896
startTime	long: millis	817496667
to	ShenandoahHeapRegionState	Empty Committed
used	ulong: bytes	0

ShenandoahHeapRegionInformation

startTime duration every chunk 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: ShenandoahGC

Missing in: G1GC, ParallelGC, SerialGC, ZGC

Information about a specific heap region in the Shenandoah GC

Configuration	enabled	period
default	false	everyChunk
profiling	false	everyChunk

Field	Type	Description
index	uint	Index
state	ShenandoahHeapRegionState	State Consider contributing a description to jfreventcollector.
start	ulong: address	Start
used	ulong: bytes	Used

Examples 1

ShenandoahGC

index	uint	20
start	ulong: address	30106714112
startTime	long: millis	363233958
state	ShenandoahHeapRegionState	Empty Committed
used	ulong: bytes	0

GCLocker

default profiling startTime eventThread stackTrace 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	stackTrace	threshold
default	true	true	1 s
profiling	true	true	100 ms

Field	Type	Description
lockCount	uint	Lock Count The number of Java threads in a critical section when the GC locker is started
stallCount	uint	Stall Count The number of Java threads stalled by the GC locker

JVM: GC: Heap

GCHeapSummary

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / GC / Heap

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled
default	true
profiling	true

Field	Type	Description
gcId	uint	GC Identifier
when	GCWhen	When Consider contributing a description to jfreventcollector.
heapSpace	VirtualSpace struct	Heap Space Consider contributing a description to jfreventcollector.
heapUsed	ulong: bytes	Heap Used Bytes allocated by objects in the heap

Examples 3

gcId	uint	5
heapSpace	VirtualSpace
committedEnd	ulong: address	30389305344
committedSize	ulong: bytes	324534272
reservedEnd	ulong: address	34359738368
reservedSize	ulong: bytes	4294967296
start	ulong: address	30064771072
heapUsed	ulong: bytes	44501240
startTime	long: millis	1175872458
when	GCWhen	After GC

gcId	uint	42
heapSpace	VirtualSpace
committedEnd	ulong: address	31811698688
committedSize	ulong: bytes	1746927616
reservedEnd	ulong: address	34359738368
reservedSize	ulong: bytes	4294967296
start	ulong: address	30064771072
heapUsed	ulong: bytes	605115040
startTime	long: millis	12094130875
when	GCWhen	After GC

gcId	uint	52
heapSpace	VirtualSpace
committedEnd	ulong: address	30324359168
committedSize	ulong: bytes	259588096
reservedEnd	ulong: address	34359738368
reservedSize	ulong: bytes	4294967296
start	ulong: address	30064771072
heapUsed	ulong: bytes	93403336
startTime	long: millis	5355450042
when	GCWhen	After GC

MetaspaceSummary

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / GC / Heap

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled
default	true
profiling	true

Field	Type	Description
gcId	uint	GC Identifier
when	GCWhen	When Consider contributing a description to jfreventcollector.
gcThreshold	ulong: bytes	GC Threshold
metaspace	MetaspaceSizes struct	Total Consider contributing a description to jfreventcollector.
dataSpace	MetaspaceSizes struct	Data Consider contributing a description to jfreventcollector.
classSpace	MetaspaceSizes struct	Class Consider contributing a description to jfreventcollector.

Examples 3

classSpace	MetaspaceSizes
committed	ulong: bytes	2490368
reserved	ulong: bytes	1073741824
used	ulong: bytes	2421352
dataSpace	MetaspaceSizes
committed	ulong: bytes	20512768
reserved	ulong: bytes	67108864
used	ulong: bytes	20385288
gcId	uint	3
gcThreshold	ulong: bytes	36700160
metaspace	MetaspaceSizes
committed	ulong: bytes	23003136
reserved	ulong: bytes	1140850688
used	ulong: bytes	22806640
startTime	long: millis	1087489208
when	GCWhen	After GC

classSpace	MetaspaceSizes
committed	ulong: bytes	3080192
reserved	ulong: bytes	1073741824
used	ulong: bytes	2830240
dataSpace	MetaspaceSizes
committed	ulong: bytes	23396352
reserved	ulong: bytes	67108864
used	ulong: bytes	23220816
gcId	uint	28
gcThreshold	ulong: bytes	42729472
metaspace	MetaspaceSizes
committed	ulong: bytes	26476544
reserved	ulong: bytes	1140850688
used	ulong: bytes	26051056
startTime	long: millis	7657987042
when	GCWhen	After GC

classSpace	MetaspaceSizes
committed	ulong: bytes	2686976
reserved	ulong: bytes	1073741824
used	ulong: bytes	2521952
dataSpace	MetaspaceSizes
committed	ulong: bytes	21168128
reserved	ulong: bytes	67108864
used	ulong: bytes	21010016
gcId	uint	14
gcThreshold	ulong: bytes	38338560
metaspace	MetaspaceSizes
committed	ulong: bytes	23855104
reserved	ulong: bytes	1140850688
used	ulong: bytes	23531968
startTime	long: millis	2190589292
when	GCWhen	After GC

PSHeapSummary

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / GC / Heap

Appearing in: ParallelGC

Missing in: G1GC, SerialGC, ShenandoahGC, ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled
default	true
profiling	true

Field	Type	Description
gcId	uint	GC Identifier
when	GCWhen	When Consider contributing a description to jfreventcollector.
oldSpace	VirtualSpace struct	Old Space Consider contributing a description to jfreventcollector.
oldObjectSpace	ObjectSpace struct	Old Object Space Consider contributing a description to jfreventcollector.
youngSpace	VirtualSpace struct	Young Space Consider contributing a description to jfreventcollector.
edenSpace	ObjectSpace struct	Eden Space Consider contributing a description to jfreventcollector.
fromSpace	ObjectSpace struct	From Space Consider contributing a description to jfreventcollector.
toSpace	ObjectSpace struct	To Space Consider contributing a description to jfreventcollector.

Examples 1

ParallelGC

edenSpace	ObjectSpace
end	ulong: address	33919860736
size	ulong: bytes	991428608
start	ulong: address	32928432128
used	ulong: bytes	991428608
fromSpace	ObjectSpace
end	ulong: address	34353971200
size	ulong: bytes	213909504
start	ulong: address	34140061696
used	ulong: bytes	3695728
gcId	uint	44
oldObjectSpace	ObjectSpace
end	ulong: address	30407131136
size	ulong: bytes	342360064
start	ulong: address	30064771072
used	ulong: bytes	176957048
oldSpace	VirtualSpace
committedEnd	ulong: address	30407131136
committedSize	ulong: bytes	342360064
reservedEnd	ulong: address	32928432128
reservedSize	ulong: bytes	2863661056
start	ulong: address	30064771072
startTime	long: millis	27186597542
toSpace	ObjectSpace
end	ulong: address	34136915968
size	ulong: bytes	217055232
start	ulong: address	33919860736
used	ulong: bytes	0
when	GCWhen	Before GC
youngSpace	VirtualSpace
committedEnd	ulong: address	34353971200
committedSize	ulong: bytes	1425539072
reservedEnd	ulong: address	34359738368
reservedSize	ulong: bytes	1431306240
start	ulong: address	32928432128

G1HeapSummary

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / GC / Heap

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled
default	true
profiling	true

Field	Type	Description
gcId	uint	GC Identifier
when	GCWhen	When Consider contributing a description to jfreventcollector.
edenUsedSize	ulong: bytes	Eden Used Size
edenTotalSize	ulong: bytes	Eden Total Size
survivorUsedSize	ulong: bytes	Survivor Used Size
numberOfRegions	uint	Number of Regions

Examples 1

G1GC

edenTotalSize	ulong: bytes	54847368
edenUsedSize	ulong: bytes	54525952
gcId	uint	14
numberOfRegions	uint	76
startTime	long: millis	1876266292
survivorUsedSize	ulong: bytes	3872888
when	GCWhen	Before GC

JVM: GC: Metaspace

MetaspaceGCThreshold

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / GC / Metaspace

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled
default	true
profiling	true

Field	Type	Description
oldValue	ulong: bytes	Old Value
newValue	ulong: bytes	New Value
updater	GCThresholdUpdater	Updater Consider contributing a description to jfreventcollector.

Examples 3

newValue	ulong: bytes	42729472
oldValue	ulong: bytes	38469632
startTime	long: millis	6122275834
updater	GCThresholdUpdater	compute_new_size

newValue	ulong: bytes	155123712
oldValue	ulong: bytes	143196160
startTime	long: millis	60301725000
updater	GCThresholdUpdater	compute_new_size

newValue	ulong: bytes	50397184
oldValue	ulong: bytes	42860544
startTime	long: millis	6574879375
updater	GCThresholdUpdater	compute_new_size

MetaspaceAllocationFailure

default profiling startTime stackTrace 11 17 21 23 24

Category: Java Virtual Machine / GC / Metaspace

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	stackTrace
default	true	true
profiling	true	true

Field	Type	Description
classLoader	ClassLoader	Class Loader Consider contributing a description to jfreventcollector.
hiddenClassLoader	boolean 15+	Hidden Class Loader
size	ulong: bytes	Size
metadataType	MetadataType	Metadata Type Consider contributing a description to jfreventcollector.
metaspaceObjectType	MetaspaceObjectType	Metaspace Object Type Consider contributing a description to jfreventcollector.

Examples 3

classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hiddenClassLoader	boolean	false
metadataType	MetadataType	Metadata
metaspaceObjectType	MetaspaceObjectType	ConstantPool
size	ulong: bytes	2440
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	(Ljava/lang/ClassLoader;Ljava/lang/String;[BIILjava/security/ProtectionDomain;Ljava/lang/String;)Ljava/lang/Class;
hidden	boolean	false
modifiers	int	264
name	string	defineClass1
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	1057
name	string	java/lang/ClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	967526042

classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hiddenClassLoader	boolean	false
metadataType	MetadataType	Metadata
metaspaceObjectType	MetaspaceObjectType	Method
size	ulong: bytes	88
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	(Ljava/lang/ClassLoader;Ljava/lang/String;[BIILjava/security/ProtectionDomain;Ljava/lang/String;)Ljava/lang/Class;
hidden	boolean	false
modifiers	int	264
name	string	defineClass1
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	1057
name	string	java/lang/ClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	858453667

classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hiddenClassLoader	boolean	false
metadataType	MetadataType	Metadata
metaspaceObjectType	MetaspaceObjectType	ConstMethod
size	ulong: bytes	104
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	(Ljava/lang/ClassLoader;Ljava/lang/String;[BIILjava/security/ProtectionDomain;Ljava/lang/String;)Ljava/lang/Class;
hidden	boolean	false
modifiers	int	264
name	string	defineClass1
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	1057
name	string	java/lang/ClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	1430932917

MetaspaceOOM

default profiling startTime stackTrace 11 17 21 23 24

Category: Java Virtual Machine / GC / Metaspace

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	stackTrace
default	true	true
profiling	true	true

Field	Type	Description
classLoader	ClassLoader	Class Loader Consider contributing a description to jfreventcollector.
hiddenClassLoader	boolean 15+	Hidden Class Loader
size	ulong: bytes	Size
metadataType	MetadataType	Metadata Type Consider contributing a description to jfreventcollector.
metaspaceObjectType	MetaspaceObjectType	Metaspace Object Type Consider contributing a description to jfreventcollector.

MetaspaceChunkFreeListSummary

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / GC / Metaspace

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled
default	true
profiling	true

Field	Type	Description
gcId	uint	GC Identifier
when	GCWhen	When Consider contributing a description to jfreventcollector.
metadataType	MetadataType	Metadata Type Consider contributing a description to jfreventcollector.
specializedChunks	ulong	Specialized Chunks
specializedChunksTotalSize	ulong: bytes	Specialized Chunks Total Size
smallChunks	ulong	Small Chunks
smallChunksTotalSize	ulong: bytes	Small Chunks Total Size
mediumChunks	ulong	Medium Chunks
mediumChunksTotalSize	ulong: bytes	Medium Chunks Total Size
humongousChunks	ulong	Humongous Chunks
humongousChunksTotalSize	ulong: bytes	Humongous Chunks Total Size

Examples 3

gcId	uint	11
humongousChunks	ulong	0
humongousChunksTotalSize	ulong: bytes	0
mediumChunks	ulong	0
mediumChunksTotalSize	ulong: bytes	0
metadataType	MetadataType	Class
smallChunks	ulong	0
smallChunksTotalSize	ulong: bytes	0
specializedChunks	ulong	0
specializedChunksTotalSize	ulong: bytes	0
startTime	long: millis	1775255667
when	GCWhen	Before GC

gcId	uint	8
humongousChunks	ulong	0
humongousChunksTotalSize	ulong: bytes	0
mediumChunks	ulong	0
mediumChunksTotalSize	ulong: bytes	0
metadataType	MetadataType	Class
smallChunks	ulong	0
smallChunksTotalSize	ulong: bytes	0
specializedChunks	ulong	0
specializedChunksTotalSize	ulong: bytes	0
startTime	long: millis	1335274250
when	GCWhen	Before GC

gcId	uint	19
humongousChunks	ulong	0
humongousChunksTotalSize	ulong: bytes	0
mediumChunks	ulong	0
mediumChunksTotalSize	ulong: bytes	0
metadataType	MetadataType	Class
smallChunks	ulong	0
smallChunksTotalSize	ulong: bytes	0
specializedChunks	ulong	0
specializedChunksTotalSize	ulong: bytes	0
startTime	long: millis	1820947000
when	GCWhen	Before GC

JVM: GC: Phases

GCPhasePause

default profiling startTime duration eventThread 11 17 21 23 24 graal vm

Category: Java Virtual Machine / GC / Phases

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	threshold
default	true	0 ms
profiling	true	0 ms

Field	Type	Description
gcId	uint	GC Identifier
name	string	Name

Examples 3

gcId	uint	24
name	string	GC Pause
startTime	long: millis	6415161375

gcId	uint	38
name	string	GC Pause
startTime	long: millis	22934919875

gcId	uint	43
name	string	GC Pause
startTime	long: millis	4697268250

GCPhasePauseLevel1

default profiling startTime duration eventThread 11 17 21 23 24 graal vm

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Missing in: ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	threshold
default	true	0 ms
profiling	true	0 ms

Field	Type	Description
gcId	uint	GC Identifier
name	string	Name

Examples 3

gcId	uint	29
name	string	Notify Soft/WeakReferences
startTime	long: millis	1953472875

gcId	uint	23
name	string	Phase 2: Prepare compaction
startTime	long: millis	6098202834

gcId	uint	22
name	string	Pre Compact
startTime	long: millis	9077608042

GCPhasePauseLevel2

default profiling startTime duration eventThread 11 17 21 23 24 graal vm

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	threshold
default	true	0 ms
profiling	true	0 ms

Field	Type	Description
gcId	uint	GC Identifier
name	string	Name

Examples 3

gcId	uint	43
name	string	Phase 2: Determine work lists
startTime	long: millis	12692416417

gcId	uint	16
name	string	Weak Processing
startTime	long: millis	4558157375

gcId	uint	147
name	string	Class Unloading
startTime	long: millis	30299137583

GCPhasePauseLevel3

startTime duration eventThread 11 17 21 23 24 graal vm

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	threshold
default	false	0 ms
profiling	false	0 ms

Field	Type	Description
gcId	uint	GC Identifier
name	string	Name

Examples 3

gcId	uint	76
name	string	Trigger cleanups
startTime	long: millis	60228661542

gcId	uint	8
name	string	Notify and keep alive finalizable
startTime	long: millis	1333295250

gcId	uint	78
name	string	Notify Soft/WeakReferences
startTime	long: millis	24725653625

GCPhasePauseLevel4

startTime duration eventThread 11 17 21 23 24 graal vm

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ParallelGC

Missing in: SerialGC, ShenandoahGC, ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	threshold
default	false	0 ms
profiling	false	0 ms

Field	Type	Description
gcId	uint	GC Identifier
name	string	Name

Examples 2

ParallelGC
G1GC

gcId	uint	60
name	string	Balance queues
startTime	long: millis	39102642917

gcId	uint	161
name	string	Balance queues
startTime	long: millis	51172097625

GCPhaseConcurrent

default profiling startTime duration eventThread 11 17 21 23 24

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ShenandoahGC, ZGC

Missing in: ParallelGC, SerialGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	threshold
default	true	0 ms
profiling	true	0 ms

Field	Type	Description
gcId	uint	GC Identifier
name	string	Name

Examples 3

gcId	uint	14
name	string	Concurrent Mark
startTime	long: millis	20846453000

gcId	uint	3
name	string	Concurrent Mark Roots
startTime	long: millis	4504408292

gcId	uint	130
name	string	Concurrent Clear Claimed Marks
startTime	long: millis	46154430084

GCPhaseConcurrentLevel1

default profiling startTime duration eventThread 15 17 21 23 24

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ShenandoahGC, ZGC

Missing in: ParallelGC, SerialGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	threshold
default	true	0 ms
profiling	true	0 ms

Field	Type	Description
gcId	uint	GC Identifier
name	string	Name

Examples 3

gcId	uint	32
name	string	ClassLoaderData
startTime	long: millis	52654364542

gcId	uint	29
name	string	ClassLoaderData
startTime	long: millis	39412916250

gcId	uint	130
name	string	Preclean SoftReferences
startTime	long: millis	46108917125

GCPhaseParallel

default profiling startTime duration eventThread 12 17 21 23 24

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ShenandoahGC

Missing in: ParallelGC, SerialGC, ZGC

GC phases for parallel workers

Configuration	enabled	threshold
default	true	0 ms
profiling	true	0 ms

Field	Type	Description
gcId	uint	GC Identifier
gcWorkerId	uint	GC Worker Identifier
name	string	Name

Examples 2

G1GC
ShenandoahGC

gcId	uint	3
gcWorkerId	uint	0
name	string	ObjCopy
startTime	long: millis	940675625

gcId	uint	5
gcWorkerId	uint	2
name	string	Update Region States
startTime	long: millis	6826722833

JVM: GC: Reference

GCReferenceStatistics

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / GC / Reference

Total count of processed references during GC

Configuration	enabled
default	true
profiling	true

Field	Type	Description
gcId	uint	GC Identifier
type	ReferenceType	Type Consider contributing a description to jfreventcollector.
count	ulong	Total Count

Examples 3

count	ulong	0
gcId	uint	22
startTime	long: millis	2837824167
type	ReferenceType	Soft reference

count	ulong	0
gcId	uint	31
startTime	long: millis	1976006625
type	ReferenceType	Soft reference

count	ulong	15
gcId	uint	23
startTime	long: millis	11102771250
type	ReferenceType	Phantom reference

JVM: Profiling

OldObjectSample

cutoff default profiling startTime eventThread stackTrace 11 17 21 23 24

Category: Java Virtual Machine / Profiling

A potential memory leak

Configuration	cutoff	enabled	stackTrace
default	0 ns	true	false
profiling	0 ns	true	true

Field	Type	Description
allocationTime	Ticks	Allocation Time Consider contributing a description to jfreventcollector.
objectAge	Tickspan 14+	Object Age Consider contributing a description to jfreventcollector.
lastKnownHeapUsage	ulong: bytes	Last Known Heap Usage
object	OldObject	Object Consider contributing a description to jfreventcollector.
arrayElements	int	Array Elements If the object is an array, the number of elements, or minimum value for the type int if it is not an array
root	OldObjectGcRoot	GC Root Consider contributing a description to jfreventcollector.

Examples 3

allocationTime	Ticks	93744122083
arrayElements	int	-2147483648
lastKnownHeapUsage	ulong: bytes	117658120
object	OldObject
address	ulong: address	30180806312
description	string	null
referrer	Reference	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	48
name	string	java/util/concurrent/SynchronousQueue$TransferStack$SNode
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/concurrent
objectAge	Tickspan	322788167
root	OldObjectGcRoot	null
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	4
lineNumber	int	328
method	Method
descriptor	string	(Ljava/util/concurrent/SynchronousQueue$TransferStack$SNode;Ljava/lang/Object;Ljava/util/concurrent/SynchronousQueue$TransferStack$SNode;I)Ljava/util/concurrent/SynchronousQueue$TransferStack$SNode;
hidden	boolean	false
modifiers	int	8
name	string	snode
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	48
name	string	java/util/concurrent/SynchronousQueue$TransferStack
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/concurrent
type	FrameType	Inlined
		…
truncated	boolean	false
startTime	long: millis	94066910250

allocationTime	Ticks	6649468250
arrayElements	int	-2147483648
lastKnownHeapUsage	ulong: bytes	81595784
object	OldObject
address	ulong: address	31577641576
description	string	null
referrer	Reference	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/lang/Class
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
objectAge	Tickspan	92318529458
root	OldObjectGcRoot	null
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	(Ljava/lang/ClassLoader;Ljava/lang/Class;Ljava/lang/String;[BIILjava/security/ProtectionDomain;ZILjava/lang/Object;)Ljava/lang/Class;
hidden	boolean	false
modifiers	int	264
name	string	defineClass0
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	1057
name	string	java/lang/ClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	98967997708

allocationTime	Ticks	61966638875
arrayElements	int	64
lastKnownHeapUsage	ulong: bytes	111141904
object	OldObject
address	ulong: address	30176358424
description	string	null
referrer	Reference	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	0
name	string	[Ljava/util/concurrent/ForkJoinTask;
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/concurrent
objectAge	Tickspan	16033886334
root	OldObjectGcRoot	null
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	32
lineNumber	int	1607
method	Method
descriptor	string	(Ljava/util/concurrent/ForkJoinPool$WorkQueue;)V
hidden	boolean	false
modifiers	int	16
name	string	registerWorker
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/concurrent/ForkJoinPool
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/concurrent
type	FrameType	Interpreted
truncated	boolean	false
startTime	long: millis	78000525209

ExecutionSample

default profiling startTime every chunk 11 17 21 23 24 graal vm

Category: Java Virtual Machine / Profiling

Snapshot of a threads state

Configuration	enabled	period
default	true	20 ms
profiling	true	10 ms

Field	Type	Description
sampledThread	Thread	Thread Consider contributing a description to jfreventcollector.
stackTrace	StackTrace	Stack Trace Consider contributing a description to jfreventcollector.
state	ThreadState	Thread State

Examples 3

sampledThread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	ForkJoinPool.commonPool-worker-5
javaThreadId	long	27
osName	string	ForkJoinPool.commonPool-worker-5
osThreadId	long	26627
virtual	boolean	false
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	12
lineNumber	int	50
method	Method
descriptor	string	()Ljava/lang/Object;
hidden	boolean	false
modifiers	int	0
name	string	get
type	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	false
modifiers	int	48
name	string	io/jenetics/util/Context
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	io/jenetics/util
type	FrameType	Inlined
		…
truncated	boolean	false
startTime	long: millis	4268090125
state	ThreadState	STATE_RUNNABLE

sampledThread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	ForkJoinPool.commonPool-worker-4
javaThreadId	long	34
osName	string	ForkJoinPool.commonPool-worker-4
osThreadId	long	26115
virtual	boolean	false
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	5
lineNumber	int	54
method	Method
descriptor	string	(I)Ljava/lang/Object;
hidden	boolean	false
modifiers	int	1
name	string	get
type	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	false
modifiers	int	49
name	string	io/jenetics/internal/collection/ObjectStore
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	io/jenetics/internal/collection
type	FrameType	Inlined
		…
truncated	boolean	false
startTime	long: millis	4976860542
state	ThreadState	STATE_RUNNABLE

sampledThread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	ForkJoinPool.commonPool-worker-1
javaThreadId	long	36
osName	string	ForkJoinPool.commonPool-worker-1
osThreadId	long	43015
virtual	boolean	false
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	5
lineNumber	int	164
method	Method
descriptor	string	(J)V
hidden	boolean	false
modifiers	int	1
name	string	begin
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/stream/ReduceOps$3ReducingSink
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/stream
type	FrameType	JIT compiled
		…
truncated	boolean	false
startTime	long: millis	2335476500
state	ThreadState	STATE_RUNNABLE

NativeMethodSample

default profiling startTime every chunk 11 17 21 23 24 graal vm

Category: Java Virtual Machine / Profiling

Snapshot of a threads state when in native

Configuration	enabled	period
default	true	20 ms
profiling	true	20 ms

Field	Type	Description
sampledThread	Thread	Thread Consider contributing a description to jfreventcollector.
stackTrace	StackTrace	Stack Trace Consider contributing a description to jfreventcollector.
state	ThreadState	Thread State

Examples 3

sampledThread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	ForkJoinPool-1-worker-2
javaThreadId	long	32
osName	string	ForkJoinPool-1-worker-2
osThreadId	long	26891
virtual	boolean	false
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	(Ljava/lang/Class;)Ljava/lang/Object;
hidden	boolean	false
modifiers	int	257
name	string	allocateInstance
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	jdk/internal/misc/Unsafe
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	jdk/internal/misc
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	4382789167
state	ThreadState	STATE_RUNNABLE

sampledThread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	main
javaThreadId	long	1
osName	string	main
osThreadId	long	8451
virtual	boolean	false
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	(Ljava/io/FileDescriptor;JI)I
hidden	boolean	false
modifiers	int	264
name	string	write0
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	sun/nio/ch/UnixFileDispatcherImpl
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	sun/nio/ch
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	3224319792
state	ThreadState	STATE_RUNNABLE

sampledThread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	main
javaThreadId	long	1
osName	string	main
osThreadId	long	10499
virtual	boolean	false
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	(J[BII[BII)J
hidden	boolean	false
modifiers	int	258
name	string	inflateBytesBytes
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/zip/Inflater
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/zip
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	2711858625
state	ThreadState	STATE_RUNNABLE

JVM: Runtime

BiasedLockRevocation

default profiling startTime duration eventThread stackTrace 11 17 until JDK 18

Category: Java Virtual Machine / Runtime

Revoked bias of object

Configuration	enabled	stackTrace	threshold
default	true	true	0 ms
profiling	true	true	0 ms

Field	Type	Description
lockClass	Class	Lock Class Class of object whose biased lock was revoked
safepointId	ulong	Safepoint Identifier
previousOwner	Thread	Previous Owner Thread owning the bias before revocation

BiasedLockSelfRevocation

default profiling startTime duration eventThread stackTrace 11 17 until JDK 18

Category: Java Virtual Machine / Runtime

Revoked bias of object biased towards own thread

Configuration	enabled	stackTrace	threshold
default	true	true	0 ms
profiling	true	true	0 ms

Field	Type	Description
lockClass	Class	Lock Class Class of object whose biased lock was revoked

BiasedLockClassRevocation

default profiling startTime duration eventThread stackTrace 11 17 until JDK 18

Category: Java Virtual Machine / Runtime

Revoked biases for all instances of a class

Configuration	enabled	stackTrace	threshold
default	true	true	0 ms
profiling	true	true	0 ms

Field	Type	Description
revokedClass	Class	Revoked Class Class whose biased locks were revoked
disableBiasing	boolean	Disable Further Biasing Whether further biasing for instances of this class will be allowed
safepointId	ulong	Safepoint Identifier

ReservedStackActivation

default profiling startTime eventThread stackTrace 11 17 21 23 24

Category: Java Virtual Machine / Runtime

Activation of Reserved Stack Area caused by stack overflow with ReservedStackAccess annotated method in call stack

Configuration	enabled	stackTrace
default	true	true
profiling	true	true

Field	Type	Description
method	Method	Java Method

SafepointBegin

default profiling startTime duration eventThread 11 17 21 23 24 graal vm

Category: Java Virtual Machine / Runtime / Safepoint

Safepointing begin

Configuration	enabled	threshold
default	true	10 ms
profiling	true	0 ms

Field	Type	Description
safepointId	ulong	Safepoint Identifier
totalThreadCount	int	Total Threads The total number of threads at the start of safe point
jniCriticalThreadCount	int	JNI Critical Threads The number of threads in JNI critical sections

Examples 3

jniCriticalThreadCount	int	0
safepointId	ulong	39
startTime	long: millis	1871350458
totalThreadCount	int	21

jniCriticalThreadCount	int	0
safepointId	ulong	60
startTime	long: millis	8705424583
totalThreadCount	int	47

jniCriticalThreadCount	int	0
safepointId	ulong	104
startTime	long: millis	18976616667
totalThreadCount	int	27

SafepointStateSynchronization

startTime duration eventThread 11 17 21 23 24

Category: Java Virtual Machine / Runtime / Safepoint

Synchronize run state of threads

Configuration	enabled	threshold
default	false	10 ms
profiling	false	0 ms

Field	Type	Description
safepointId	ulong	Safepoint Identifier
initialThreadCount	int	Initial Threads The number of threads running at the beginning of state check
runningThreadCount	int	Running Threads The number of threads still running
iterations	int	Iterations Number of state check iterations

Examples 3

initialThreadCount	int	0
iterations	int	1
runningThreadCount	int	0
safepointId	ulong	104
startTime	long: millis	25683246042

initialThreadCount	int	0
iterations	int	1
runningThreadCount	int	0
safepointId	ulong	82
startTime	long: millis	6402579333

initialThreadCount	int	12
iterations	int	5
runningThreadCount	int	0
safepointId	ulong	68
startTime	long: millis	8240749792

SafepointCleanup

startTime duration eventThread 11 17 21 until JDK 23

Category: Java Virtual Machine / Runtime / Safepoint

Safepointing begin running cleanup tasks

Configuration	enabled	threshold
default	false	10 ms
profiling	false	0 ms

Field	Type	Description
safepointId	ulong	Safepoint Identifier

Examples 3

safepointId	ulong	53
startTime	long: millis	3668307417

safepointId	ulong	51
startTime	long: millis	7952474833

safepointId	ulong	90
startTime	long: millis	12862302625

SafepointCleanupTask

startTime duration eventThread 11 17 21 until JDK 23

Category: Java Virtual Machine / Runtime / Safepoint

Safepointing begin running cleanup tasks

Configuration	enabled	threshold
default	false	10 ms
profiling	false	0 ms

Field	Type	Description
safepointId	ulong	Safepoint Identifier
name	string	Task Name The task name

Examples 3

name	string	updating inline caches
safepointId	ulong	43
startTime	long: millis	5929672834

name	string	updating inline caches
safepointId	ulong	62
startTime	long: millis	8751950333

name	string	updating inline caches
safepointId	ulong	76
startTime	long: millis	5564933875

SafepointEnd

startTime duration eventThread 11 17 21 23 24 graal vm

Category: Java Virtual Machine / Runtime / Safepoint

Safepointing end

Configuration	enabled	threshold
default	false	10 ms
profiling	false	0 ms

Field	Type	Description
safepointId	ulong	Safepoint Identifier

Examples 3

safepointId	ulong	21
startTime	long: millis	1498600250

safepointId	ulong	64
startTime	long: millis	8754194833

safepointId	ulong	37
startTime	long: millis	2611074000

ExecuteVMOperation

default profiling startTime duration eventThread 11 17 21 23 24 graal vm

Category: Java Virtual Machine / Runtime

Execution of a VM Operation

Configuration	enabled	threshold
default	true	10 ms
profiling	true	0 ms

Field	Type	Description
operation	VMOperationType	Operation Consider contributing a description to jfreventcollector.
safepoint	boolean	At Safepoint If the operation occured at a safepoint
blocking	boolean	Caller Blocked If the calling thread was blocked until the operation was complete
caller	Thread	Caller Thread requesting operation. If non-blocking, will be set to 0 indicating thread is unknown
safepointId	ulong	Safepoint Identifier The safepoint (if any) under which this operation was completed

Examples 3

blocking	boolean	true
caller	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	ForkJoinPool.commonPool-worker-1
javaThreadId	long	23
osName	string	ForkJoinPool.commonPool-worker-1
osThreadId	long	31751
virtual	boolean	false
operation	VMOperationType	GenCollectForAllocation
safepoint	boolean	true
safepointId	ulong	37
startTime	long: millis	1844098125

blocking	boolean	true
caller	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	main
javaThreadId	long	1
osName	string	main
osThreadId	long	8451
virtual	boolean	false
operation	VMOperationType	G1CollectForAllocation
safepoint	boolean	true
safepointId	ulong	21
startTime	long: millis	1775242167

blocking	boolean	true
caller	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	main
javaThreadId	long	1
osName	string	main
osThreadId	long	10499
virtual	boolean	false
operation	VMOperationType	GC_HeapInspection
safepoint	boolean	true
safepointId	ulong	8
startTime	long: millis	423750458

Shutdown

default profiling startTime eventThread stackTrace 11 17 21 23 24

Category: Java Virtual Machine / Runtime

JVM shutting down

Configuration	enabled	stackTrace
default	true	true
profiling	true	true

Field	Type	Description
reason	string	Reason Reason for JVM shutdown

Examples 3

reason	string	Shutdown requested from Java
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	()V
hidden	boolean	false
modifiers	int	264
name	string	beforeHalt
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/lang/Shutdown
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	94066455250

reason	string	Shutdown requested from Java
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	()V
hidden	boolean	false
modifiers	int	264
name	string	beforeHalt
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/lang/Shutdown
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	98967385458

reason	string	Shutdown requested from Java
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	()V
hidden	boolean	false
modifiers	int	264
name	string	beforeHalt
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/lang/Shutdown
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	77999546542

SymbolTableStatistics

default profiling startTime duration every chunk 13 17 21 23 24

Category: Java Virtual Machine / Runtime / Tables

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	10 s
profiling	true	10 s

Field	Type	Description
bucketCount	ulong	Bucket Count Number of buckets
entryCount	ulong	Entry Count Number of all entries
totalFootprint	ulong: bytes	Total Footprint Total memory footprint (the table itself plus all of the entries)
bucketCountMaximum	ulong	Maximum Bucket Count The maximum bucket length (entries in a single bucket)
bucketCountAverage	float	Average Bucket Count The average bucket length
bucketCountVariance	float	Bucket Count Variance How far bucket lengths are spread out from their average value
bucketCountStandardDeviation	float	Bucket Count Standard Deviation How far bucket lengths are spread out from their mean (expected) value
insertionRate	float	Insertion Rate How many items were added since last event (per second)
removalRate	float	Removal Rate How many items were removed since last event (per second)

Examples 3

bucketCount	ulong	32768
bucketCountAverage	float	4.830597
bucketCountMaximum	ulong	17
bucketCountStandardDeviation	float	2.2189333
bucketCountVariance	float	4.9236646
entryCount	ulong	158289
insertionRate	float	596.0924
removalRate	float	39.040924
startTime	long: millis	67209831250
totalFootprint	ulong: bytes	13549664

bucketCount	ulong	32768
bucketCountAverage	float	2.5381775
bucketCountMaximum	ulong	11
bucketCountStandardDeviation	float	1.6117458
bucketCountVariance	float	2.5977247
entryCount	ulong	83171
insertionRate	float	54640.0
removalRate	float	11848.0
startTime	long: millis	10764493125
totalFootprint	ulong: bytes	6189624

bucketCount	ulong	32768
bucketCountAverage	float	2.541809
bucketCountMaximum	ulong	11
bucketCountStandardDeviation	float	1.6120155
bucketCountVariance	float	2.5985937
entryCount	ulong	83290
insertionRate	float	12.549684
removalRate	float	0.08595674
startTime	long: millis	22284224375
totalFootprint	ulong: bytes	6201080

StringTableStatistics

default profiling startTime duration every chunk 13 17 21 23 24

Category: Java Virtual Machine / Runtime / Tables

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	10 s
profiling	true	10 s

Field	Type	Description
bucketCount	ulong	Bucket Count Number of buckets
entryCount	ulong	Entry Count Number of all entries
totalFootprint	ulong: bytes	Total Footprint Total memory footprint (the table itself plus all of the entries)
bucketCountMaximum	ulong	Maximum Bucket Count The maximum bucket length (entries in a single bucket)
bucketCountAverage	float	Average Bucket Count The average bucket length
bucketCountVariance	float	Bucket Count Variance How far bucket lengths are spread out from their average value
bucketCountStandardDeviation	float	Bucket Count Standard Deviation How far bucket lengths are spread out from their mean (expected) value
insertionRate	float	Insertion Rate How many items were added since last event (per second)
removalRate	float	Removal Rate How many items were removed since last event (per second)

Examples 3

bucketCount	ulong	65536
bucketCountAverage	float	0.34371948
bucketCountMaximum	ulong	6
bucketCountStandardDeviation	float	0.5813279
bucketCountVariance	float	0.33794212
entryCount	ulong	22526
insertionRate	float	1223.0361
removalRate	float	193.10052
startTime	long: millis	32373892667
totalFootprint	ulong: bytes	2499552

bucketCount	ulong	65536
bucketCountAverage	float	0.5464325
bucketCountMaximum	ulong	6
bucketCountStandardDeviation	float	0.7264649
bucketCountVariance	float	0.52775127
entryCount	ulong	35811
insertionRate	float	1141.8413
removalRate	float	140.4388
startTime	long: millis	62136716959
totalFootprint	ulong: bytes	3004792

bucketCount	ulong	65536
bucketCountAverage	float	0.3635559
bucketCountMaximum	ulong	6
bucketCountStandardDeviation	float	0.5964412
bucketCountVariance	float	0.35574213
entryCount	ulong	23826
insertionRate	float	85.65229
removalRate	float	3.1796675
startTime	long: millis	55378510000
totalFootprint	ulong: bytes	2640712

PlaceholderTableStatistics

default profiling startTime duration every chunk 17 until JDK 20

Category: Java Virtual Machine / Runtime / Tables

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	10 s
profiling	true	10 s

Field	Type	Description
bucketCount	ulong	Bucket Count Number of buckets
entryCount	ulong	Entry Count Number of all entries
totalFootprint	ulong: bytes	Total Footprint Total memory footprint (the table itself plus all of the entries)
bucketCountMaximum	ulong	Maximum Bucket Count The maximum bucket length (entries in a single bucket)
bucketCountAverage	float	Average Bucket Count The average bucket length
bucketCountVariance	float	Bucket Count Variance How far bucket lengths are spread out from their average value
bucketCountStandardDeviation	float	Bucket Count Standard Deviation How far bucket lengths are spread out from their mean (expected) value
insertionRate	float	Insertion Rate How many items were added since last event (per second)
removalRate	float	Removal Rate How many items were removed since last event (per second)

LoaderConstraintsTableStatistics

default profiling startTime duration every chunk 17 until JDK 20

Category: Java Virtual Machine / Runtime / Tables

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	10 s
profiling	true	10 s

Field	Type	Description
bucketCount	ulong	Bucket Count
entryCount	ulong	Entry Count Number of all entries
totalFootprint	ulong: bytes	Total Footprint Total memory footprint (the table itself plus all of the entries)
bucketCountMaximum	ulong	Maximum Bucket Count The maximum bucket length (entries in a single bucket)
bucketCountAverage	float	Average Bucket Count The average bucket length
bucketCountVariance	float	Bucket Count Variance How far bucket lengths are spread out from their average value
bucketCountStandardDeviation	float	Bucket Count Standard Deviation How far bucket lengths are spread out from their mean (expected) value
insertionRate	float	Insertion Rate How many items were added since last event (per second)
removalRate	float	Removal Rate How many items were removed since last event (per second)

ProtectionDomainCacheTableStatistics

default profiling startTime duration every chunk 17 until JDK 20

Category: Java Virtual Machine / Runtime / Tables

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	10 s
profiling	true	10 s

Field	Type	Description
bucketCount	ulong	Bucket Count Number of buckets
entryCount	ulong	Entry Count Number of all entries
totalFootprint	ulong: bytes	Total Footprint Total memory footprint (the table itself plus all of the entries)
bucketCountMaximum	ulong	Maximum Bucket Count The maximum bucket length (entries in a single bucket)
bucketCountAverage	float	Average Bucket Count The average bucket length
bucketCountVariance	float	Bucket Count Variance How far bucket lengths are spread out from their average value
bucketCountStandardDeviation	float	Bucket Count Standard Deviation How far bucket lengths are spread out from their mean (expected) value
insertionRate	float	Insertion Rate How many items were added since last event (per second)
removalRate	float	Removal Rate How many items were removed since last event (per second)

ThreadDump

default profiling startTime duration every chunk 11 17 21 23 24

Category: Java Virtual Machine / Runtime

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	everyChunk
profiling	true	60 s

Field	Type	Description
result	string	Thread Dump

Examples 3

result	string	2023-12-18 12:45:49 Full thread dump OpenJDK 64-Bit Server VM (21.0.1+12-LTS mixed mode): Threads class SMR info: _java_thread_list=0x00006000003cd500, length=77, elements={ 0x000000011f00f200, 0x000000010e038800, 0x000000010e03b200, 0x000000011f80ec00, 0x000000011f80c800, 0x000000011f811600, 0x000…
startTime	long: millis	63501309417

result	string	2023-12-18 13:32:26 Full thread dump OpenJDK 64-Bit Server VM (21.0.1+12-LTS mixed mode): Threads class SMR info: _java_thread_list=0x00006000017c1400, length=143, elements={ 0x000000014200b400, 0x0000000144010800, 0x000000013200aa00, 0x0000000144044800, 0x0000000144041800, 0x0000000142009800, 0x00…
startTime	long: millis	62136723709

result	string	2023-12-18 12:47:28 Full thread dump OpenJDK 64-Bit Server VM (21.0.1+12-LTS mixed mode): Threads class SMR info: _java_thread_list=0x000060000092cca0, length=77, elements={ 0x0000000132812000, 0x0000000131017000, 0x0000000131014c00, 0x000000013203b200, 0x0000000132008200, 0x0000000132009600, 0x000…
startTime	long: millis	67214999000

NativeLibrary

default profiling startTime every chunk 11 17 21 23 24

Category: Java Virtual Machine / Runtime

Information about a dynamic library or other native image loaded by the JVM process

Configuration	enabled	period
default	true	everyChunk
profiling	true	everyChunk

Field	Type	Description
name	string	Name
baseAddress	ulong: address	Base Address Starting address of the module
topAddress	ulong: address	Top Address Ending address of the module, if available

Examples 3

baseAddress	ulong: address	8558223360
name	string	/System/Library/PrivateFrameworks/CollectionViewCore.framework/Versions/A/CollectionViewCore
startTime	long: millis	675848959
topAddress	ulong: address	0

baseAddress	ulong: address	6707646464
name	string	/System/Library/PrivateFrameworks/CoreUI.framework/Versions/A/CoreUI
startTime	long: millis	364596583
topAddress	ulong: address	0

baseAddress	ulong: address	6766358528
name	string	/usr/lib/system/libquarantine.dylib
startTime	long: millis	423214667
topAddress	ulong: address	0

ModuleRequire

default profiling startTime every chunk 11 17 21 23 24

Category: Java Virtual Machine / Runtime / Modules

A directed edge representing a dependency

Configuration	enabled	period
default	true	endChunk
profiling	true	endChunk

Field	Type	Description
source	Module	Source Module
requiredModule	Module	Required Module Consider contributing a description to jfreventcollector.

Examples 3

requiredModule	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.management
name	string	java.management
version	string	21.0.1
source	Module
classLoader	ClassLoader
name	string	app
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	jdk/internal/loader/ClassLoaders$AppClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	jdk/internal/loader
location	string	jrt:/jdk.jconsole
name	string	jdk.jconsole
version	string	21.0.1
startTime	long: millis	16763952708

requiredModule	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.naming
name	string	java.naming
version	string	21.0.1
source	Module
classLoader	ClassLoader
name	string	platform
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	jdk/internal/loader/ClassLoaders$PlatformClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	jdk/internal/loader
location	string	jrt:/jdk.security.auth
name	string	jdk.security.auth
version	string	21.0.1
startTime	long: millis	14998474333

requiredModule	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.datatransfer
name	string	java.datatransfer
version	string	21.0.1
source	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.desktop
name	string	java.desktop
version	string	21.0.1
startTime	long: millis	12401797959

ModuleExport

default profiling startTime every chunk 11 17 21 23 24

Category: Java Virtual Machine / Runtime / Modules

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	endChunk
profiling	true	endChunk

Field	Type	Description
exportedPackage	Package	Exported Package Consider contributing a description to jfreventcollector.
targetModule	Module	Target Module Module to which the package is qualifiedly exported. If null or N/A, the package is unqualifiedly exported

Examples 3

exportedPackage	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	app
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	jdk/internal/loader/ClassLoaders$AppClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	jdk/internal/loader
location	string	jrt:/jdk.internal.ed
name	string	jdk.internal.ed
version	string	21.0.1
name	string	jdk/internal/editor/spi
startTime	long: millis	14998523917
targetModule	Module
classLoader	ClassLoader
name	string	app
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	jdk/internal/loader/ClassLoaders$AppClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	jdk/internal/loader
location	string	jrt:/jdk.editpad
name	string	jdk.editpad
version	string	21.0.1

exportedPackage	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	scala/collection/concurrent
startTime	long: millis	12401834834
targetModule	Module	null

exportedPackage	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	scala/collection/concurrent
startTime	long: millis	16764024625
targetModule	Module	null

Java Application

ThreadStart

default profiling startTime eventThread stackTrace 11 17 21 23 24 graal vm

Category: Java Application

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	stackTrace
default	true	true
profiling	true	true

Field	Type	Description
thread	Thread	New Java Thread
parentThread	Thread	Parent Java Thread

Examples 3

parentThread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	ForkJoinPool-1-worker-2
javaThreadId	long	32
osName	string	ForkJoinPool-1-worker-2
osThreadId	long	26891
virtual	boolean	false
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	2
lineNumber	int	2573
method	Method
descriptor	string	(Ljava/lang/Thread;Ljdk/internal/vm/ThreadContainer;)V
hidden	boolean	false
modifiers	int	1
name	string	start
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/lang/System$2
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	5081114583
thread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	ForkJoinPool-1-worker-7
javaThreadId	long	37
osName	string	ForkJoinPool-1-worker-7
osThreadId	long	33283
virtual	boolean	false

parentThread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	UCT-akka.actor.default-dispatcher-5
javaThreadId	long	79
osName	string	UCT-akka.actor.default-dispatcher-5
osThreadId	long	47619
virtual	boolean	false
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	2
lineNumber	int	2573
method	Method
descriptor	string	(Ljava/lang/Thread;Ljdk/internal/vm/ThreadContainer;)V
hidden	boolean	false
modifiers	int	1
name	string	start
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/lang/System$2
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	8721945833
thread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	UCT-akka.actor.default-dispatcher-14
javaThreadId	long	88
osName	string	UCT-akka.actor.default-dispatcher-14
osThreadId	long	61443
virtual	boolean	false

parentThread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	UCT-akka.actor.default-dispatcher-11
javaThreadId	long	133
osName	string	UCT-akka.actor.default-dispatcher-11
osThreadId	long	45063
virtual	boolean	false
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	2
lineNumber	int	2573
method	Method
descriptor	string	(Ljava/lang/Thread;Ljdk/internal/vm/ThreadContainer;)V
hidden	boolean	false
modifiers	int	1
name	string	start
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/lang/System$2
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	11758672750
thread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	UCT-akka.actor.default-dispatcher-16
javaThreadId	long	138
osName	string	UCT-akka.actor.default-dispatcher-16
osThreadId	long	82955
virtual	boolean	false

ThreadEnd

default profiling startTime eventThread 11 17 21 23 24 graal vm

Category: Java Application

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled
default	true
profiling	true

Field	Type	Description
thread	Thread	Java Thread

Examples 3

startTime	long: millis	1413234542
thread	Thread
group	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	C2 CompilerThread2
javaThreadId	long	11
osName	string	C2 CompilerThread2
osThreadId	long	31747
virtual	boolean	false

startTime	long: millis	11457724875
thread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	UCT-akka.actor.internal-dispatcher-20
javaThreadId	long	120
osName	string	UCT-akka.actor.internal-dispatcher-20
osThreadId	long	82947
virtual	boolean	false

startTime	long: millis	10752787708
thread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	UCT-akka.actor.default-dispatcher-10
javaThreadId	long	58
osName	string	UCT-akka.actor.default-dispatcher-10
osThreadId	long	40963
virtual	boolean	false

ThreadSleep

default profiling startTime duration eventThread stackTrace 11 17 21 until JDK 23

Category: Java Application

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	stackTrace	threshold
default	true	true	20 ms
profiling	true	true	10 ms

Field	Type	Description
time	long: millis	Sleep Time

Examples 3

stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	5
lineNumber	int	474
method	Method
descriptor	string	(Ljdk/internal/event/ThreadSleepEvent;)V
hidden	boolean	false
modifiers	int	10
name	string	afterSleep
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/lang/Thread
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	8314002958
time	long: millis	8000000

stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	5
lineNumber	int	474
method	Method
descriptor	string	(Ljdk/internal/event/ThreadSleepEvent;)V
hidden	boolean	false
modifiers	int	10
name	string	afterSleep
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/lang/Thread
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	8867219250
time	long: millis	9000000

stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	5
lineNumber	int	474
method	Method
descriptor	string	(Ljdk/internal/event/ThreadSleepEvent;)V
hidden	boolean	false
modifiers	int	10
name	string	afterSleep
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/lang/Thread
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	8795922292
time	long: millis	9000000

ThreadPark

default profiling startTime duration eventThread stackTrace 11 17 21 23 24 graal vm

Category: Java Application

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	stackTrace	threshold
default	true	true	20 ms
profiling	true	true	10 ms

Field	Type	Description
parkedClass	Class	Class Parked On
timeout	long: nanos	Park Timeout
until	long: epochmillis	Park Until
address	ulong: address	Address of Object Parked

Examples 3

address	ulong: address	31586136128
parkedClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/concurrent/ForkJoinPool
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/concurrent
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	(ZJ)V
hidden	boolean	false
modifiers	int	257
name	string	park
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	jdk/internal/misc/Unsafe
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	jdk/internal/misc
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	4295443000
timeout	long: nanos	-9223372036854775808
until	long: epochmillis	-9223372036854775808

address	ulong: address	30352314792
parkedClass	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	false
modifiers	int	49
name	string	scala/concurrent/impl/ExecutionContextImpl$$anon$3
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	scala/concurrent/impl
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	(ZJ)V
hidden	boolean	false
modifiers	int	257
name	string	park
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	jdk/internal/misc/Unsafe
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	jdk/internal/misc
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	8123247667
timeout	long: nanos	-9223372036854775808
until	long: epochmillis	-9223372036854775808

address	ulong: address	30156597904
parkedClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/concurrent/ForkJoinPool
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/concurrent
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	(ZJ)V
hidden	boolean	false
modifiers	int	257
name	string	park
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	jdk/internal/misc/Unsafe
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	jdk/internal/misc
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	5665590667
timeout	long: nanos	-9223372036854775808
until	long: epochmillis	-9223372036854775808

JavaMonitorEnter

default profiling startTime duration eventThread stackTrace 11 17 21 23 24 graal vm

Category: Java Application

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	stackTrace	threshold
default	true	true	20 ms
profiling	true	true	10 ms

Field	Type	Description
monitorClass	Class	Monitor Class Consider contributing a description to jfreventcollector.
previousOwner	Thread	Previous Monitor Owner
address	ulong: address	Monitor Address

Examples 3

address	ulong: address	105553170730032
monitorClass	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	false
modifiers	int	33
name	string	edu/rice/habanero/actors/AkkaActorState$actorLatch$
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	edu/rice/habanero/actors
previousOwner	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	UCT-akka.actor.default-dispatcher-5
javaThreadId	long	45
osName	string	UCT-akka.actor.default-dispatcher-5
osThreadId	long	28167
virtual	boolean	false
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	-1
lineNumber	int	115
method	Method
descriptor	string	()V
hidden	boolean	false
modifiers	int	33
name	string	countUp
type	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	false
modifiers	int	33
name	string	edu/rice/habanero/actors/AkkaActorState$actorLatch$
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	edu/rice/habanero/actors
type	FrameType	Inlined
		…
truncated	boolean	false
startTime	long: millis	7569123250

address	ulong: address	105553162252064
monitorClass	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	false
modifiers	int	33
name	string	edu/rice/habanero/actors/AkkaActorState$actorLatch$
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	edu/rice/habanero/actors
previousOwner	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	UCT-akka.actor.default-dispatcher-7
javaThreadId	long	57
osName	string	UCT-akka.actor.default-dispatcher-7
osThreadId	long	38403
virtual	boolean	false
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	-1
lineNumber	int	109
method	Method
descriptor	string	()V
hidden	boolean	false
modifiers	int	33
name	string	countDown
type	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	false
modifiers	int	33
name	string	edu/rice/habanero/actors/AkkaActorState$actorLatch$
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	edu/rice/habanero/actors
type	FrameType	Inlined
		…
truncated	boolean	false
startTime	long: millis	9265720417

address	ulong: address	105553176308912
monitorClass	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	false
modifiers	int	33
name	string	edu/rice/habanero/actors/AkkaActorState$actorLatch$
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	edu/rice/habanero/actors
previousOwner	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	UCT-akka.actor.default-dispatcher-9
javaThreadId	long	56
osName	string	UCT-akka.actor.default-dispatcher-9
osThreadId	long	36355
virtual	boolean	false
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	-1
lineNumber	int	109
method	Method
descriptor	string	()V
hidden	boolean	false
modifiers	int	33
name	string	countDown
type	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	false
modifiers	int	33
name	string	edu/rice/habanero/actors/AkkaActorState$actorLatch$
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	edu/rice/habanero/actors
type	FrameType	Inlined
		…
truncated	boolean	false
startTime	long: millis	8188014958

JavaMonitorWait

default profiling startTime duration eventThread stackTrace 11 17 21 23 24 graal vm

Category: Java Application

Waiting on a Java monitor

Configuration	enabled	stackTrace	threshold
default	true	true	20 ms
profiling	true	true	10 ms

Field	Type	Description
monitorClass	Class	Monitor Class Class of object waited on
notifier	Thread	Notifier Thread Notifying Thread
timeout	long: millis	Timeout Maximum wait time
timedOut	boolean	Timed Out Wait has been timed out
address	ulong: address	Monitor Address Address of object waited on

Examples 3

address	ulong: address	105553435798496
monitorClass	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	false
modifiers	int	33
name	string	scala/concurrent/stm/ccstm/TxnLevelImpl
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	scala/concurrent/stm/ccstm
notifier	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	Thread-38
javaThreadId	long	367
osName	string	Thread-38
osThreadId	long	56587
virtual	boolean	false
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	(J)V
hidden	boolean	false
modifiers	int	274
name	string	wait0
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/lang/Object
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	76185669542
timedOut	boolean	false
timeout	long: millis	0

address	ulong: address	105553176813696
monitorClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/TaskQueue
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util
notifier	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	main
javaThreadId	long	1
osName	string	main
osThreadId	long	10499
virtual	boolean	false
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	(J)V
hidden	boolean	false
modifiers	int	274
name	string	wait0
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/lang/Object
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	45181072292
timedOut	boolean	false
timeout	long: millis	0

address	ulong: address	105553161718208
monitorClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/TaskQueue
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util
notifier	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	main
javaThreadId	long	1
osName	string	main
osThreadId	long	8451
virtual	boolean	false
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	(J)V
hidden	boolean	false
modifiers	int	274
name	string	wait0
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/lang/Object
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	36506844792
timedOut	boolean	false
timeout	long: millis	0

JavaMonitorInflate

profiling startTime duration eventThread stackTrace 11 17 21 23 24 graal vm

Category: Java Application

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	stackTrace	threshold
default	false	true	20 ms
profiling	true	true	10 ms

Field	Type	Description
monitorClass	Class	Monitor Class Consider contributing a description to jfreventcollector.
address	ulong: address	Monitor Address
cause	InflateCause	Monitor Inflation Cause Cause of inflation

ObjectAllocationInNewTLAB

startTime eventThread stackTrace 11 17 21 23 24 graal vm

Category: Java Application

Allocation in new Thread Local Allocation Buffer

Configuration	enabled	stackTrace
default	false	true
profiling	false	true

Field	Type	Description
objectClass	Class	Object Class Class of allocated object
allocationSize	ulong: bytes	Allocation Size
tlabSize	ulong: bytes	TLAB Size

Examples 3

allocationSize	ulong: bytes	144
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	0
name	string	[I
package	Package	null
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	143
lineNumber	int	1934
method	Method
descriptor	string	()V
hidden	boolean	false
modifiers	int	2
name	string	compile
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/util/regex/Pattern
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/regex
type	FrameType	JIT compiled
		…
truncated	boolean	false
startTime	long: millis	1031470958
tlabSize	ulong: bytes	1394656

allocationSize	ulong: bytes	88
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/util/regex/Pattern
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/regex
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	1101
method	Method
descriptor	string	(Ljava/lang/String;)Ljava/util/regex/Pattern;
hidden	boolean	false
modifiers	int	9
name	string	compile
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/util/regex/Pattern
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/regex
type	FrameType	Inlined
		…
truncated	boolean	false
startTime	long: millis	1040037333
tlabSize	ulong: bytes	1342264

allocationSize	ulong: bytes	120
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/lang/Class
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	(Ljava/lang/ClassLoader;Ljava/lang/String;[BIILjava/security/ProtectionDomain;Ljava/lang/String;)Ljava/lang/Class;
hidden	boolean	false
modifiers	int	264
name	string	defineClass1
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	1057
name	string	java/lang/ClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	948848209
tlabSize	ulong: bytes	39456

ObjectAllocationOutsideTLAB

startTime eventThread stackTrace 11 17 21 23 24

Category: Java Application

Allocation outside Thread Local Allocation Buffers

Configuration	enabled	stackTrace
default	false	true
profiling	false	true

Field	Type	Description
objectClass	Class	Object Class Class of allocated object
allocationSize	ulong: bytes	Allocation Size

Examples 3

allocationSize	ulong: bytes	23416
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	0
name	string	[Ljava/lang/Object;
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	6
lineNumber	int	3482
method	Method
descriptor	string	([Ljava/lang/Object;I)[Ljava/lang/Object;
hidden	boolean	false
modifiers	int	9
name	string	copyOf
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/util/Arrays
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util
type	FrameType	Inlined
		…
truncated	boolean	false
startTime	long: millis	2020420833

allocationSize	ulong: bytes	10960
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	0
name	string	[B
package	Package	null
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	64
lineNumber	int	89
method	Method
descriptor	string	(Ljava/io/InputStream;Ljava/util/zip/Inflater;I)V
hidden	boolean	false
modifiers	int	1
name	string	<init>
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/zip/InflaterInputStream
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/zip
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	955517417

allocationSize	ulong: bytes	24
objectClass	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	false
modifiers	int	49
name	string	io/jenetics/MutatorResult
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	io/jenetics
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	142
method	Method
descriptor	string	(Ljava/lang/Object;)Lio/jenetics/MutatorResult;
hidden	boolean	false
modifiers	int	9
name	string	of
type	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	false
modifiers	int	49
name	string	io/jenetics/MutatorResult
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	io/jenetics
type	FrameType	Inlined
		…
truncated	boolean	false
startTime	long: millis	5545005083

ObjectAllocationSample

throttle default profiling startTime eventThread stackTrace 16 17 21 23 24

Category: Java Application

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	stackTrace	throttle
default	true	true	150/s
profiling	true	true	300/s

Field	Type	Description
objectClass	Class	Object Class Class of allocated object
weight	long: bytes	Sample Weight The relative weight of the sample. Aggregating the weights for a large number of samples, for a particular class, thread or stack trace, gives a statistically accurate representation of the allocation pressure

Examples 3

objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	0
name	string	[Ljava/lang/Object;
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	93
lineNumber	int	143
method	Method
descriptor	string	(J)V
hidden	boolean	false
modifiers	int	20
name	string	ensureCapacity
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/stream/SpinedBuffer
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/stream
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	1500694084
weight	long: bytes	1104608

objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/lang/String
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	7
lineNumber	int	752
method	Method
descriptor	string	([BII)Ljava/lang/String;
hidden	boolean	false
modifiers	int	9
name	string	newString
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	48
name	string	java/lang/StringLatin1
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Inlined
		…
truncated	boolean	false
startTime	long: millis	909920167
weight	long: bytes	1432920

objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/lang/String
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	7
lineNumber	int	752
method	Method
descriptor	string	([BII)Ljava/lang/String;
hidden	boolean	false
modifiers	int	9
name	string	newString
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	48
name	string	java/lang/StringLatin1
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Inlined
		…
truncated	boolean	false
startTime	long: millis	1045025125
weight	long: bytes	1341160

JavaErrorThrow

default profiling startTime duration stackTrace 11 17 21 until JDK 23

Source src/jdk.jfr/share/classes/jdk/jfr/events/ErrorThrownEvent.java

Category: Java Application

An object derived from java.lang.Error has been created. OutOfMemoryErrors are ignored

Configuration	enabled	stackTrace
default	true	true
profiling	true	true

Field	Type	Description
message	string	Message Consider contributing a description to jfreventcollector.
thrownClass	Class	Class Consider contributing a description to jfreventcollector.

Examples 3

message	string	'java.lang.Object java.lang.invoke.DirectMethodHandle$Holder.newInvokeSpecial(java.lang.Object, java.lang.Object, int, java.lang.Object)'
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	7
lineNumber	int	68
method	Method
descriptor	string	(Ljava/lang/String;)V
hidden	boolean	false
modifiers	int	1
name	string	<init>
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/lang/Error
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	4036698833
thrownClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/lang/NoSuchMethodError
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang

message	string	Exception java.lang.ExceptionInInitializerError [in thread "main"]
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	8
lineNumber	int	86
method	Method
descriptor	string	(Ljava/lang/String;Ljava/lang/Throwable;)V
hidden	boolean	false
modifiers	int	1
name	string	<init>
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/lang/Error
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	5833800917
thrownClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/lang/ExceptionInInitializerError
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang

message	string	Found class java.lang.Object, but interface was expected
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	7
lineNumber	int	68
method	Method
descriptor	string	(Ljava/lang/String;)V
hidden	boolean	false
modifiers	int	1
name	string	<init>
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/lang/Error
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	1512448250
thrownClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/lang/IncompatibleClassChangeError
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang

FileForce

default profiling startTime duration stackTrace 11 17 21 until JDK 23

Source src/jdk.jfr/share/classes/jdk/jfr/events/FileForceEvent.java

Category: Java Application

Force updates to be written to file

Configuration	enabled	stackTrace	threshold
default	true	true	20 ms
profiling	true	true	10 ms

Field	Type	Description
path	string	Path Full path of the file
metaData	boolean	Update Metadata Whether the file metadata is updated

SocketWrite

default profiling startTime duration stackTrace 11 17 21 until JDK 23

Source src/jdk.jfr/share/classes/jdk/jfr/events/SocketWriteEvent.java

Category: Java Application

Writing data to a socket

Configuration	enabled	stackTrace	threshold
default	true	true	20 ms
profiling	true	true	10 ms

Field	Type	Description
host	string	Remote Host
address	string	Remote Address
port	int	Remote Port
bytesWritten	long: bytes	Bytes Written Number of bytes written to the socket

Examples 3

address	string	127.0.0.1
bytesWritten	long: bytes	91
host	string	localhost
port	int	56559
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	584
lineNumber	int	191
method	Method
descriptor	string	([Ljava/nio/ByteBuffer;II)J
hidden	boolean	false
modifiers	int	1
name	string	write
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	sun/nio/ch/SocketChannelImpl
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	sun/nio/ch
type	FrameType	JIT compiled
		…
truncated	boolean	false
startTime	long: millis	63730556375

address	string	127.0.0.1
bytesWritten	long: bytes	50
host	string
port	int	52660
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	584
lineNumber	int	191
method	Method
descriptor	string	([Ljava/nio/ByteBuffer;II)J
hidden	boolean	false
modifiers	int	1
name	string	write
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	sun/nio/ch/SocketChannelImpl
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	sun/nio/ch
type	FrameType	JIT compiled
		…
truncated	boolean	true
startTime	long: millis	40857771375

address	string	127.0.0.1
bytesWritten	long: bytes	50
host	string
port	int	52294
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	584
lineNumber	int	191
method	Method
descriptor	string	([Ljava/nio/ByteBuffer;II)J
hidden	boolean	false
modifiers	int	1
name	string	write
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	sun/nio/ch/SocketChannelImpl
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	sun/nio/ch
type	FrameType	JIT compiled
		…
truncated	boolean	true
startTime	long: millis	34356472417

JavaExceptionThrow

startTime duration stackTrace 11 17 21 until JDK 23

Source src/jdk.jfr/share/classes/jdk/jfr/events/ExceptionThrownEvent.java

Category: Java Application

An object derived from java.lang.Exception has been created

Configuration	enabled	stackTrace
default	false	true
profiling	false	true

Field	Type	Description
message	string	Message Consider contributing a description to jfreventcollector.
thrownClass	Class	Class Consider contributing a description to jfreventcollector.

Examples 3

message	string	scala.collection.IndexedSeq
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	40
lineNumber	int	298
method	Method
descriptor	string	(Ljava/lang/String;Ljava/lang/Throwable;)V
hidden	boolean	false
modifiers	int	1
name	string	<init>
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/lang/Throwable
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	687401833
thrownClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/lang/ClassNotFoundException
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang

message	string	scala.collection.AbstractIterable
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	40
lineNumber	int	298
method	Method
descriptor	string	(Ljava/lang/String;Ljava/lang/Throwable;)V
hidden	boolean	false
modifiers	int	1
name	string	<init>
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/lang/Throwable
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	568750250
thrownClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/lang/ClassNotFoundException
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang

message	string	scala.collection.immutable.Seq
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	40
lineNumber	int	298
method	Method
descriptor	string	(Ljava/lang/String;Ljava/lang/Throwable;)V
hidden	boolean	false
modifiers	int	1
name	string	<init>
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/lang/Throwable
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	901245042
thrownClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/lang/ClassNotFoundException
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang

FileWrite

default profiling startTime duration stackTrace 11 17 21 until JDK 23

Source src/jdk.jfr/share/classes/jdk/jfr/events/FileWriteEvent.java

Category: Java Application

Appearing in: G1GC, ParallelGC, ShenandoahGC, ZGC

Missing in: SerialGC

Writing data to a file

Configuration	enabled	stackTrace	threshold
default	true	true	20 ms
profiling	true	true	10 ms

Field	Type	Description
path	string	Path Full path of the file
bytesWritten	long: bytes	Bytes Written Number of bytes written to the file

Examples 3

bytesWritten	long: bytes	120
path	string	null
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	171
lineNumber	int	103
method	Method
descriptor	string	([BII)V
hidden	boolean	false
modifiers	int	1
name	string	write
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/io/FileOutputStream
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/io
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	56404662458

bytesWritten	long: bytes	16384
path	string	harness-124802-11372319207631724376/apache-spark/lib/spark-sql_2.13-3.2.0.jar
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	678
lineNumber	int	154
method	Method
descriptor	string	(Ljava/nio/ByteBuffer;)I
hidden	boolean	false
modifiers	int	1
name	string	write
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	sun/nio/ch/FileChannelImpl
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	sun/nio/ch
type	FrameType	JIT compiled
		…
truncated	boolean	false
startTime	long: millis	2721627083

bytesWritten	long: bytes	8980
path	string	harness-133125-7262456833842592188/apache-spark/lib/hadoop-client-api-3.3.1.jar
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	678
lineNumber	int	154
method	Method
descriptor	string	(Ljava/nio/ByteBuffer;)I
hidden	boolean	false
modifiers	int	1
name	string	write
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	sun/nio/ch/FileChannelImpl
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	sun/nio/ch
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	3346476750

SocketRead

default profiling startTime duration stackTrace 11 17 21 until JDK 23

Source src/jdk.jfr/share/classes/jdk/jfr/events/SocketReadEvent.java

Category: Java Application

Reading data from a socket

Configuration	enabled	stackTrace	threshold
default	true	true	20 ms
profiling	true	true	10 ms

Field	Type	Description
host	string	Remote Host
address	string	Remote Address
port	int	Remote Port
timeout	long: millis	Timeout Value
bytesRead	long: bytes	Bytes Read Number of bytes read from the socket
endOfStream	boolean	End of Stream If end of stream was reached

Examples 3

address	string	127.0.0.1
bytesRead	long: bytes	65
endOfStream	boolean	false
host	string
port	int	52655
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	846
lineNumber	int	72
method	Method
descriptor	string	(Ljava/nio/ByteBuffer;)I
hidden	boolean	false
modifiers	int	1
name	string	read
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	sun/nio/ch/SocketChannelImpl
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	sun/nio/ch
type	FrameType	JIT compiled
		…
truncated	boolean	false
startTime	long: millis	40501067417
timeout	long: millis	0

address	string	127.0.0.1
bytesRead	long: bytes	1
endOfStream	boolean	false
host	string
port	int	56509
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	846
lineNumber	int	72
method	Method
descriptor	string	(Ljava/nio/ByteBuffer;)I
hidden	boolean	false
modifiers	int	1
name	string	read
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	sun/nio/ch/SocketChannelImpl
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	sun/nio/ch
type	FrameType	JIT compiled
		…
truncated	boolean	false
startTime	long: millis	27866042250
timeout	long: millis	0

address	string	127.0.0.1
bytesRead	long: bytes	39
endOfStream	boolean	false
host	string
port	int	52475
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	846
lineNumber	int	72
method	Method
descriptor	string	(Ljava/nio/ByteBuffer;)I
hidden	boolean	false
modifiers	int	1
name	string	read
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	sun/nio/ch/SocketChannelImpl
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	sun/nio/ch
type	FrameType	JIT compiled
		…
truncated	boolean	false
startTime	long: millis	86479423500
timeout	long: millis	0

FileRead

default profiling startTime duration stackTrace 11 17 21 until JDK 23

Source src/jdk.jfr/share/classes/jdk/jfr/events/FileReadEvent.java

Category: Java Application

Appearing in: SerialGC, ZGC

Missing in: G1GC, ParallelGC, ShenandoahGC

Reading data from a file

Configuration	enabled	stackTrace	threshold
default	true	true	20 ms
profiling	true	true	10 ms

Field	Type	Description
path	string	Path Full path of the file
bytesRead	long: bytes	Bytes Read Number of bytes read from the file (possibly 0)
endOfFile	boolean	End of File If end of file was reached

Examples 2

SerialGC
ZGC

bytesRead	long: bytes	4
endOfFile	boolean	false
path	string	[...]/code/experiments/jfreventcollector/harness-124622-12434569844652140370/apache-spark/lib/avro-ipc-1.10.2.jar
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	114
lineNumber	int	114
method	Method
descriptor	string	([BII)I
hidden	boolean	false
modifiers	int	1
name	string	read
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/io/RandomAccessFile
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/io
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	28227785042

bytesRead	long: bytes	4
endOfFile	boolean	false
path	string	[...]/code/experiments/jfreventcollector/harness-124931-6974251686310067154/apache-spark/lib/curator-recipes-2.13.0.jar
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	114
lineNumber	int	114
method	Method
descriptor	string	([BII)I
hidden	boolean	false
modifiers	int	1
name	string	read
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/io/RandomAccessFile
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/io
type	FrameType	Inlined
		…
truncated	boolean	false
startTime	long: millis	30635721500

Java Application Statistics

JavaThreadStatistics

default profiling startTime duration every chunk 11 17 21 23 24 graal vm

Category: Java Application / Statistics

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	1000 ms
profiling	true	1000 ms

Field	Type	Description
activeCount	long	Active Threads Number of live active threads including both daemon and non-daemon threads
daemonCount	long	Daemon Threads Number of live daemon threads
accumulatedCount	long	Accumulated Threads Number of threads created and also started since JVM start
peakCount	long	Peak Threads Peak live thread count since JVM start or when peak count was reset

Examples 3

accumulatedCount	long	115
activeCount	long	63
daemonCount	long	22
peakCount	long	63
startTime	long: millis	12666264500

accumulatedCount	long	411
activeCount	long	138
daemonCount	long	129
peakCount	long	138
startTime	long: millis	71224045250

accumulatedCount	long	349
activeCount	long	74
daemonCount	long	73
peakCount	long	84
startTime	long: millis	85643545667

ClassLoadingStatistics

default profiling startTime duration every chunk 11 17 21 23 24 graal vm

Category: Java Application / Statistics

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	1000 ms
profiling	true	1000 ms

Field	Type	Description
loadedClassCount	long	Loaded Class Count Number of classes loaded since JVM start
unloadedClassCount	long	Unloaded Class Count Number of classes unloaded since JVM start

Examples 3

loadedClassCount	long	13323
startTime	long: millis	26541793209
unloadedClassCount	long	3168

loadedClassCount	long	19242
startTime	long: millis	65511483958
unloadedClassCount	long	6341

loadedClassCount	long	28579
startTime	long: millis	98617493625
unloadedClassCount	long	11828

ClassLoaderStatistics

default profiling startTime duration every chunk 11 17 21 23 24

Category: Java Application / Statistics

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	everyChunk
profiling	true	everyChunk

Field	Type	Description
classLoader	ClassLoader	Class Loader Consider contributing a description to jfreventcollector.
parentClassLoader	ClassLoader	Parent Class Loader Consider contributing a description to jfreventcollector.
classLoaderData	ulong: address	ClassLoaderData Pointer Pointer to the ClassLoaderData structure in the JVM
classCount	long	Classes Number of loaded classes
chunkSize	ulong: bytes	Total Chunk Size Total size of all allocated metaspace chunks (each chunk has several blocks)
blockSize	ulong: bytes	Total Block Size Total size of all allocated metaspace blocks (each chunk has several blocks)
hiddenClassCount	long 15+	Hidden Classes Number of hidden classes
hiddenChunkSize	ulong: bytes 15+	Total Hidden Classes Chunk Size Total size of all allocated metaspace chunks for hidden classes (each chunk has several blocks)
hiddenBlockSize	ulong: bytes 15+	Total Hidden Classes Block Size Total size of all allocated metaspace blocks for hidden classes (each chunk has several blocks)

Examples 3

blockSize	ulong: bytes	20697504
chunkSize	ulong: bytes	21160960
classCount	long	2973
classLoader	ClassLoader	null
classLoaderData	ulong: address	105553176969696
hiddenBlockSize	ulong: bytes	424880
hiddenChunkSize	ulong: bytes	700416
hiddenClassCount	long	229
parentClassLoader	ClassLoader	null
startTime	long: millis	52082024167

blockSize	ulong: bytes	5510728
chunkSize	ulong: bytes	5530624
classCount	long	579
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
classLoaderData	ulong: address	105553170208224
hiddenBlockSize	ulong: bytes	0
hiddenChunkSize	ulong: bytes	0
hiddenClassCount	long	0
parentClassLoader	ClassLoader
name	string	app
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	jdk/internal/loader/ClassLoaders$AppClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	jdk/internal/loader
startTime	long: millis	60131977875

blockSize	ulong: bytes	301248
chunkSize	ulong: bytes	314368
classCount	long	119
classLoader	ClassLoader
name	string	app
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	jdk/internal/loader/ClassLoaders$AppClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	jdk/internal/loader
classLoaderData	ulong: address	105553151822496
hiddenBlockSize	ulong: bytes	0
hiddenChunkSize	ulong: bytes	0
hiddenClassCount	long	0
parentClassLoader	ClassLoader
name	string	platform
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	jdk/internal/loader/ClassLoaders$PlatformClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	jdk/internal/loader
startTime	long: millis	27600650667

ThreadAllocationStatistics

default profiling startTime every chunk 11 17 21 23 24

Category: Java Application / Statistics

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	everyChunk
profiling	true	everyChunk

Field	Type	Description
allocated	ulong: bytes	Allocated Approximate number of bytes allocated since thread start
thread	Thread	Thread Consider contributing a description to jfreventcollector.

Examples 3

allocated	ulong: bytes	272
startTime	long: millis	14906032000
thread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	scala-execution-context-global-65
javaThreadId	long	65
osName	string	scala-execution-context-global-65
osThreadId	long	37379
virtual	boolean	false

allocated	ulong: bytes	0
startTime	long: millis	12401705334
thread	Thread
group	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	Service Thread
javaThreadId	long	12
osName	string	Service Thread
osThreadId	long	23043
virtual	boolean	false

allocated	ulong: bytes	22031600
startTime	long: millis	423203583
thread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	main
javaThreadId	long	1
osName	string	main
osThreadId	long	10499
virtual	boolean	false

ExceptionStatistics

default profiling startTime duration stackTrace 11 17 21 until JDK 23

Source src/jdk.jfr/share/classes/jdk/jfr/events/ExceptionStatisticsEvent.java

Category: Java Application / Statistics

Number of objects derived from java.lang.Throwable that have been created

Configuration	enabled	period
default	true	1000 ms
profiling	true	1000 ms

Field	Type	Description
throwables	long	Exceptions Created

Examples 3

stackTrace	StackTrace	null
startTime	long: millis	31336457750
throwables	long	7192

stackTrace	StackTrace	null
startTime	long: millis	9914518750
throwables	long	2706

stackTrace	StackTrace	null
startTime	long: millis	3626960875
throwables	long	725

DirectBufferStatistics

default profiling startTime duration stackTrace 15 17 21 23 24

Source src/jdk.jfr/share/classes/jdk/jfr/events/DirectBufferStatisticsEvent.java

Category: Java Application / Statistics

Statistics of direct buffer

Configuration	enabled	period
default	true	5 s
profiling	true	5 s

Examples 3

stackTrace	StackTrace	null
startTime	long: millis	77328776625

stackTrace	StackTrace	null
startTime	long: millis	63488245750

stackTrace	StackTrace	null
startTime	long: millis	98617570792

Java Development Kit

X509Certificate

startTime duration stackTrace 11 17 21 until JDK 23

Source src/jdk.jfr/share/classes/jdk/jfr/events/X509CertificateEvent.java

Category: Java Development Kit / Security

Details of X.509 Certificate parsed by JDK

Configuration	enabled	stackTrace
default	false	true
profiling	false	true

Field	Type	Description
algorithm	string	Signature Algorithm
serialNumber	string	Serial Number Consider contributing a description to jfreventcollector.
subject	string	Subject Consider contributing a description to jfreventcollector.
issuer	string	Issuer Consider contributing a description to jfreventcollector.
keyType	string	Key Type Consider contributing a description to jfreventcollector.
keyLength	int	Key Length
certificateId	long: certificateId	Certificate Id
validFrom	long: epochmillis	Valid From
validUntil	long: epochmillis	Valid Until

Deserialization

startTime duration stackTrace 11 17 21 until JDK 23

Source src/jdk.jfr/share/classes/jdk/jfr/events/DeserializationEvent.java

Category: Java Development Kit / Serialization

Results of deserialization and ObjectInputFilter checks

Configuration	enabled	stackTrace
default	false	true
profiling	false	true

Field	Type	Description
filterConfigured	boolean	Filter Configured
filterStatus	string	Filter Status Consider contributing a description to jfreventcollector.
type	Class	Type Consider contributing a description to jfreventcollector.
arrayLength	int	Array Length
objectReferences	long	Object References
depth	long	Depth
bytesRead	long	Bytes Read
exceptionType	Class	Exception Type Consider contributing a description to jfreventcollector.
exceptionMessage	string	Exception Message Consider contributing a description to jfreventcollector.

TLSHandshake

startTime duration stackTrace 11 17 21 until JDK 23

Source src/jdk.jfr/share/classes/jdk/jfr/events/TLSHandshakeEvent.java

Category: Java Development Kit / Security

Parameters used in TLS Handshake

Configuration	enabled	stackTrace
default	false	true
profiling	false	true

Field	Type	Description
peerHost	string	Peer Host Consider contributing a description to jfreventcollector.
peerPort	int	Peer Port
protocolVersion	string	Protocol Version Consider contributing a description to jfreventcollector.
cipherSuite	string	Cipher Suite Consider contributing a description to jfreventcollector.
certificateId	long: certificateId	Certificate Id Peer Certificate Id

X509Validation

startTime duration stackTrace 11 17 21 until JDK 23

Source src/jdk.jfr/share/classes/jdk/jfr/events/X509ValidationEvent.java

Category: Java Development Kit / Security

Serial numbers from X.509 Certificates forming chain of trust

Configuration	enabled	stackTrace
default	false	true
profiling	false	true

Field	Type	Description
certificateId	long: certificateId	Certificate Id
certificatePosition	int	Certificate Position Certificate position in chain of trust, 1 = trust anchor
validationCounter	long	Validation Counter

SecurityProviderService

startTime duration stackTrace 11 17 21 until JDK 23

Source src/jdk.jfr/share/classes/jdk/jfr/events/SecurityProviderServiceEvent.java

Category: Java Development Kit / Security

Details of Provider.getInstance(String type, String algorithm) calls

Configuration	enabled	stackTrace
default	false	true
profiling	false	true

Field	Type	Description
type	string	Type of Service
algorithm	string	Algorithm Name
provider	string	Security Provider

Examples 3

algorithm	string	NativePRNG
provider	string	SUN
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	136
lineNumber	int	1298
method	Method
descriptor	string	(Ljava/lang/String;Ljava/lang/String;)Ljava/security/Provider$Service;
hidden	boolean	false
modifiers	int	1
name	string	getService
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	1057
name	string	java/security/Provider
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/security
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	783480000
type	string	SecureRandom

algorithm	string	NativePRNG
provider	string	SUN
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	136
lineNumber	int	1298
method	Method
descriptor	string	(Ljava/lang/String;Ljava/lang/String;)Ljava/security/Provider$Service;
hidden	boolean	false
modifiers	int	1
name	string	getService
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	1057
name	string	java/security/Provider
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/security
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	462983542
type	string	SecureRandom

algorithm	string	NativePRNG
provider	string	SUN
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	136
lineNumber	int	1298
method	Method
descriptor	string	(Ljava/lang/String;Ljava/lang/String;)Ljava/security/Provider$Service;
hidden	boolean	false
modifiers	int	1
name	string	getService
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	1057
name	string	java/security/Provider
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/security
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	537709583
type	string	SecureRandom

SecurityPropertyModification

startTime duration stackTrace 11 17 21 until JDK 23

Source src/jdk.jfr/share/classes/jdk/jfr/events/SecurityPropertyModificationEvent.java

Category: Java Development Kit / Security

Modification of Security property

Configuration	enabled	stackTrace
default	false	true
profiling	false	true

Field	Type	Description
key	string	Key Consider contributing a description to jfreventcollector.
value	string	Value Consider contributing a description to jfreventcollector.

InitialSecurityProperty

default profiling startTime duration stackTrace 17 21 23 24

Source src/jdk.jfr/share/classes/jdk/jfr/events/InitialSecurityPropertyEvent.java

Category: Java Development Kit / Security

Initial Security Properties

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
key	string	Key Consider contributing a description to jfreventcollector.
value	string	Value Consider contributing a description to jfreventcollector.

Examples 3

key	string	keystore.type.compat
stackTrace	StackTrace	null
startTime	long: millis	18250938375
value	string	true

key	string	keystore.type.compat
stackTrace	StackTrace	null
startTime	long: millis	13056830417
value	string	true

key	string	jceks.key.serialFilter
stackTrace	StackTrace	null
startTime	long: millis	379048875
value	string	java.base/java.lang.Enum;java.base/java.security.KeyRep;java.base/java.security.KeyRep$Type;java.base/javax.crypto.spec.SecretKeySpec;!*

Operating System

OSInformation

default profiling startTime duration end of every chunk 11 17 21 23 24 graal vm

Category: Operating System

Description of the OS the JVM runs on, for example, a uname-like output

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
osVersion	string	OS Version

Examples 3

osVersion	string	uname: Darwin 23.2.0 Darwin Kernel Version 23.2.0: Wed Nov 15 21:53:34 PST 2023; root:xnu-10002.61.3~2/RELEASE_ARM64_T8103 arm64
startTime	long: millis	30518969542

osVersion	string	uname: Darwin 23.2.0 Darwin Kernel Version 23.2.0: Wed Nov 15 21:53:34 PST 2023; root:xnu-10002.61.3~2/RELEASE_ARM64_T8103 arm64
startTime	long: millis	58733069667

osVersion	string	uname: Darwin 23.2.0 Darwin Kernel Version 23.2.0: Wed Nov 15 21:53:34 PST 2023; root:xnu-10002.61.3~2/RELEASE_ARM64_T8103 arm64
startTime	long: millis	39218559875

VirtualizationInformation

default profiling startTime duration end of every chunk 11 17 21 23 24

Category: Operating System

Description of the virtualization technology the JVM runs on

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
name	string	Name

Examples 3

name	string	No virtualization detected
startTime	long: millis	36095834834

name	string	No virtualization detected
startTime	long: millis	52080831083

name	string	No virtualization detected
startTime	long: millis	39218560708

InitialEnvironmentVariable

default profiling startTime end of every chunk 11 17 21 23 24 graal vm

Category: Operating System

Key-value pairs for environment variables at JVM startup

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
key	string	Key
value	string	Value

Examples 3

key	string	IDEA_INITIAL_DIRECTORY
startTime	long: millis	17889813583
value	string	/

key	string	SDKMAN_CANDIDATES_API
startTime	long: millis	15755091500
value	string	https://api.sdkman.io/2

key	string	GPG_TTY
startTime	long: millis	672949625
value	string	/dev/ttys004

SystemProcess

default profiling startTime duration end of every chunk 11 17 21 23 24

Category: Operating System

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	endChunk
profiling	true	endChunk

Field	Type	Description
pid	string	Process Identifier
commandLine	string	Command Line

Examples 3

commandLine	string	/usr/libexec/UserEventAgent
pid	string	535
startTime	long: millis	16726490792

commandLine	string	/usr/libexec/TouchBarServer
pid	string	784
startTime	long: millis	14787855958

commandLine	string	/System/Library/PrivateFrameworks/CoreAnalytics.framework/Support/analyticsd
pid	string	621
startTime	long: millis	12397004584

CPUInformation

default profiling startTime duration end of every chunk 11 17 21 23 24

Category: Operating System / Processor

Characteristics and descriptions of the processor(s) the JVM is running on

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
cpu	string	Type
description	string	Description
sockets	uint	Sockets
cores	uint	Cores
hwThreads	uint	Hardware Threads

Examples 3

cores	uint	8
cpu	string	AArch64
description	string	AArch64 0x61:0x0:0x1b588bb3:0, fp, asimd, aes, pmull, sha1, sha256, crc32, lse, sha3, sha512
hwThreads	uint	8
sockets	uint	8
startTime	long: millis	93733088958

cores	uint	8
cpu	string	AArch64
description	string	AArch64 0x61:0x0:0x1b588bb3:0, fp, asimd, aes, pmull, sha1, sha256, crc32, lse, sha3, sha512
hwThreads	uint	8
sockets	uint	8
startTime	long: millis	36095848750

cores	uint	8
cpu	string	AArch64
description	string	AArch64 0x61:0x0:0x1b588bb3:0, fp, asimd, aes, pmull, sha1, sha256, crc32, lse, sha3, sha512
hwThreads	uint	8
sockets	uint	8
startTime	long: millis	88121865833

CPUTimeStampCounter

default profiling startTime duration end of every chunk 11 17 21 23 24

Category: Operating System / Processor

Information about the CPU time stamp mechanism / (RD)TSC

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
fastTimeEnabled	boolean	Fast Time
fastTimeAutoEnabled	boolean	Trusted Platform
osFrequency	long: hertz	OS Frequency
fastTimeFrequency	long: hertz	Fast Time Frequency

Examples 3

fastTimeAutoEnabled	boolean	false
fastTimeEnabled	boolean	false
fastTimeFrequency	long: hertz	1000000000
osFrequency	long: hertz	1000000000
startTime	long: millis	12862208375

fastTimeAutoEnabled	boolean	false
fastTimeEnabled	boolean	false
fastTimeFrequency	long: hertz	1000000000
osFrequency	long: hertz	1000000000
startTime	long: millis	17889821333

fastTimeAutoEnabled	boolean	false
fastTimeEnabled	boolean	false
fastTimeFrequency	long: hertz	1000000000
osFrequency	long: hertz	1000000000
startTime	long: millis	364265167

CPULoad

default profiling startTime duration every chunk 11 17 21 23 24

Category: Operating System / Processor

Information about the recent CPU usage of the JVM process

Configuration	enabled	period
default	true	1000 ms
profiling	true	1000 ms

Field	Type	Description
jvmUser	float: percentage	JVM User
jvmSystem	float: percentage	JVM System
machineTotal	float: percentage	Machine Total

Examples 3

jvmSystem	float: percentage	0.0010660964
jvmUser	float: percentage	0.008008963
machineTotal	float: percentage	1.0
startTime	long: millis	92191498125

jvmSystem	float: percentage	4.632044E-4
jvmUser	float: percentage	0.008122506
machineTotal	float: percentage	0.86725664
startTime	long: millis	2415511500

jvmSystem	float: percentage	1.1073186E-4
jvmUser	float: percentage	0.0058880956
machineTotal	float: percentage	0.570529
startTime	long: millis	54020870917

ThreadCPULoad

default profiling startTime duration eventThread every chunk 11 17 21 23 24

Category: Operating System / Processor

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	10 s
profiling	true	10 s

Field	Type	Description
user	float: percentage	User Mode CPU Load User mode thread CPU load
system	float: percentage	System Mode CPU Load System mode thread CPU load

Examples 3

startTime	long: millis	10643453375
system	float: percentage	0.0060064374
user	float: percentage	0.029799215

startTime	long: millis	10760177417
system	float: percentage	0.0011801149
user	float: percentage	0.012981966

startTime	long: millis	11595339875
system	float: percentage	1.851332E-5
user	float: percentage	2.641097E-4

ThreadContextSwitchRate

default profiling startTime duration every chunk 11 17 21 23 24

Category: Operating System / Processor

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	10 s
profiling	true	10 s

Field	Type	Description
switchRate	float: hertz	Switch Rate Number of context switches per second

Examples 3

startTime	long: millis	32358574500
switchRate	float: hertz	11796.922

startTime	long: millis	88355022583
switchRate	float: hertz	5764.792

startTime	long: millis	72229818792
switchRate	float: hertz	33222.207

NetworkUtilization

default profiling startTime every chunk 11 17 21 23 24

Category: Operating System / Network

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration	enabled	period
default	true	5 s
profiling	true	5 s

Field	Type	Description
networkInterface	NetworkInterfaceName	Network Interface Network Interface Name
readRate	long: bits-per-second	Read Rate Number of incoming bits per second
writeRate	long: bits-per-second	Write Rate Number of outgoing bits per second

Examples 3

networkInterface	NetworkInterfaceName	lo0
readRate	long: bits-per-second	10730984
startTime	long: millis	72229156459
writeRate	long: bits-per-second	10730984

networkInterface	NetworkInterfaceName	en0
readRate	long: bits-per-second	3912400
startTime	long: millis	15714751750
writeRate	long: bits-per-second	2403656

networkInterface	NetworkInterfaceName	lo0
readRate	long: bits-per-second	113120
startTime	long: millis	61736952167
writeRate	long: bits-per-second	113120

PhysicalMemory

default profiling startTime duration every chunk 11 17 21 23 24 graal vm

Category: Operating System / Memory

OS Physical Memory

Configuration	enabled	period
default	true	everyChunk
profiling	true	everyChunk

Field	Type	Description
totalSize	ulong: bytes	Total Size Total amount of physical memory available to OS
usedSize	ulong: bytes	Used Size Total amount of physical memory in use

Examples 3

startTime	long: millis	15844342792
totalSize	ulong: bytes	17179869184
usedSize	ulong: bytes	17098588160

startTime	long: millis	423206667
totalSize	ulong: bytes	17179869184
usedSize	ulong: bytes	16631234560

startTime	long: millis	22149949500
totalSize	ulong: bytes	17179869184
usedSize	ulong: bytes	16003137536

ContainerConfiguration

default profiling startTime duration stackTrace 17 21 23 24

Source src/jdk.jfr/share/classes/jdk/jfr/events/ContainerConfigurationEvent.java

Category: Operating System

A set of container specific attributes

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
containerType	string	Container Type Container type information
cpuSlicePeriod	long: microseconds	CPU Slice Period Length of the scheduling period for processes within the container
cpuQuota	long: microseconds	CPU Quota Total available run-time allowed during each scheduling period for all tasks in the container
cpuShares	long	CPU Shares Relative weighting of processes with the container used for prioritizing the scheduling of processes across all containers running on a host
effectiveCpuCount	long	Effective CPU Count Number of effective processors that this container has available to it
memorySoftLimit	long: bytes	Memory Soft Limit Hint to the operating system that allows groups to specify the minimum required amount of physical memory
memoryLimit	long: bytes	Memory Limit Maximum amount of physical memory that can be allocated in the container
swapMemoryLimit	long: bytes	Memory and Swap Limit Maximum amount of physical memory and swap space, in bytes, that can be allocated in the container

ContainerCPUThrottling

default profiling startTime duration stackTrace 17 21 23 24

Source src/jdk.jfr/share/classes/jdk/jfr/events/ContainerCPUThrottlingEvent.java

Category: Operating System / Processor

Container CPU throttling related information

Configuration	enabled	period
default	true	30 s
profiling	true	30 s

Field	Type	Description
cpuElapsedSlices	long	CPU Elapsed Slices Number of time-slice periods that have elapsed if a CPU quota has been setup for the container
cpuThrottledSlices	long	CPU Throttled Slices Number of time-slice periods that the CPU has been throttled or limited due to exceeding CPU quota
cpuThrottledTime	long: nanos	CPU Throttled Time Total time duration, in nanoseconds, that the CPU has been throttled or limited due to exceeding CPU quota

ContainerMemoryUsage

default profiling startTime duration stackTrace 17 21 23 24

Source src/jdk.jfr/share/classes/jdk/jfr/events/ContainerMemoryUsageEvent.java

Category: Operating System / Memory

Container memory usage related information

Configuration	enabled	period
default	true	30 s
profiling	true	30 s

Field	Type	Description
memoryFailCount	long	Memory Fail Count Number of times that user memory requests in the container have exceeded the memory limit
memoryUsage	long: bytes	Memory Usage Amount of physical memory, in bytes, that is currently allocated in the current container
swapMemoryUsage	long: bytes	Memory and Swap Usage Amount of physical memory and swap space, in bytes, that is currently allocated in the current container

ContainerCPUUsage

default profiling startTime duration stackTrace 17 21 23 24

Source src/jdk.jfr/share/classes/jdk/jfr/events/ContainerCPUUsageEvent.java

Category: Operating System / Processor

Container CPU usage related information

Configuration	enabled	period
default	true	30 s
profiling	true	30 s

Field	Type	Description
cpuTime	long: nanos	CPU Time Aggregate time consumed by all tasks in the container
cpuUserTime	long: nanos	CPU User Time Aggregate user time consumed by all tasks in the container
cpuSystemTime	long: nanos	CPU System Time Aggregate system time consumed by all tasks in the container

ContainerIOUsage

default profiling startTime duration stackTrace 17 21 23 24

Source src/jdk.jfr/share/classes/jdk/jfr/events/ContainerIOUsageEvent.java

Category: Operating System / File System

Container IO usage related information

Configuration	enabled	period
default	true	30 s
profiling	true	30 s

Field	Type	Description
serviceRequests	long	Block IO Request Count Number of block IO requests to the disk that have been issued by the container
dataTransferred	long: bytes	Block IO Transfer Number of block IO bytes that have been transferred to/from the disk by the container

ProcessStart

default profiling startTime duration stackTrace 17 21 until JDK 23

Source src/jdk.jfr/share/classes/jdk/jfr/events/ProcessStartEvent.java

Category: Operating System

Operating system process started

Configuration	enabled	stackTrace
default	true	true
profiling	true	true

Field	Type	Description
pid	long	Process Id
directory	string	Directory Consider contributing a description to jfreventcollector.
command	string	Command Consider contributing a description to jfreventcollector.

Truffle Compiler

org.graalvm.compiler.truffle.CompilerStatistics

startTime duration every 1s graal vm only

Category: Truffle Compiler

Truffe Compiler Statistics

Field	Type	Description
compiledMethods	ulong	Compiled Methods Compiled Methods
bailouts	ulong	Bailouts Bailouts
invalidations	ulong	Invalidated Compilations Invalidated Compilations
compiledCodeSize	ulong: bytes	Compilation Resulting Size Compilation Resulting Size
totalTime	long: millis	Total Time Total Time
peakTime	long: millis	Peak Time Peak Time

org.graalvm.compiler.truffle.Deoptimization

startTime duration graal vm only

Category: Truffle Compiler

Truffle Call Target Deoptimization

Field	Type	Description
source	string	Source Compiled Source
language	string	Language Guest Language
rootFunction	string	Root Function Root Function

org.graalvm.compiler.truffle.AssumptionInvalidation

startTime duration stackTrace graal vm only

Category: Truffle Compiler

Truffle Assumption Invalidation

Field	Type	Description
source	string	Source Compiled Source
language	string	Language Guest Language
rootFunction	string	Root Function Root Function
reason	string	Reason Invalidation Reason

org.graalvm.compiler.truffle.CompilationFailure

startTime duration graal vm only

Category: Truffle Compiler

Truffe Compilation Failures

Field	Type	Description
source	string	Source Compiled Source
language	string	Language Guest Language
rootFunction	string	Root Function Root Function
permanentFailure	boolean	Permanent Failure Permanent Failure
failureReason	string	Failure Reason Failure Reason

org.graalvm.compiler.truffle.Compilation

startTime duration graal vm only

Category: Truffle Compiler

Truffe Compilation

Field	Type	Description
source	string	Source Compiled Source
language	string	Language Guest Language
rootFunction	string	Root Function Root Function
success	boolean	Succeeded Compilation Status
compiledCodeSize	uint: bytes	Compiled Code Size Compiled Code Size
compiledCodeAddress	long	Compiled Code Address Compiled Code Address
inlinedCalls	uint	Inlined Calls Inlined Calls
dispatchedCalls	uint	Dispatched Calls Dispatched Calls
graalNodeCount	uint	Graal Nodes Graal Node Count
peNodeCount	uint	Truffle Nodes Truffle Node Count
peTime	ulong	Partial Evaluation Time Partial Evaluation Time in Milliseconds

Types

Bytecode

14+

Bytecode Instruction

Field	Type	Description
bytecode	string	Instruction

Examples 3

ifnonnull

invokeinterface

invokevirtual

CalleeMethod

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
type	string	Class
name	string	Method Name
descriptor	string	Method Descriptor

Examples 3

descriptor	string	(B)V
name	string	putUncheckedByte
type	string	jdk/jfr/internal/event/EventWriter

descriptor	string	(B)V
name	string	putUncheckedByte
type	string	jdk/jfr/internal/event/EventWriter

descriptor	string	()V
name	string	<init>
type	string	java/lang/StringBuilder

ChunkHeader

14+

Chunk Header No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
payload array	byte	Payload

Class

Java Class

Field	Type	Description
classLoader	ClassLoader	Class Loader Consider contributing a description to jfreventcollector.
name	Symbol	Name Consider contributing a description to jfreventcollector.
package	Package	Package Consider contributing a description to jfreventcollector.
modifiers	int	Access Modifiers
hidden	boolean 15+	Hidden

ClassLoader

Java Class Loader

Field	Type	Description
type	Class	Type Consider contributing a description to jfreventcollector.
name	Symbol	Name Consider contributing a description to jfreventcollector.

CodeBlobType

Code Blob Type No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
type	string	Type

Examples 3

CodeHeap 'non-profiled nmethods'

CodeHeap 'non-nmethods'

CompilerPhaseType

Compiler Phase Type No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
phase	string	Phase

CompilerType

14+

Compiler Type No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
compiler	string	Compiler

Examples 3

CopyFailed

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
objectCount	ulong	Object Count
firstSize	ulong: bytes	First Failed Object Size
smallestSize	ulong: bytes	Smallest Failed Object Size
totalSize	ulong: bytes	Total Object Size

DeoptimizationAction

14+

Deoptimization Action No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
action	string	Action

Examples 3

reinterpret

maybe_recompile

DeoptimizationReason

14+

Deoptimization Reason No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
reason	string	Reason

Examples 3

class_check

unstable_if

FlagValueOrigin

Flag Value Origin No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
origin	string	Origin

Examples 3

Ergonomic

Default

FrameType

Frame type No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
description	string	Description

Examples 3

Interpreted

Native

G1EvacuationStatistics

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
gcId	uint	GC Identifier
allocated	ulong: bytes	Allocated Total memory allocated by PLABs
wasted	ulong: bytes	Wasted Total memory wasted within PLABs due to alignment or refill
used	ulong: bytes	Used Total memory occupied by objects within PLABs
undoWaste	ulong: bytes	Undo Wasted Total memory wasted due to allocation undo within PLABs
regionEndWaste	ulong: bytes	Region End Wasted Total memory wasted at the end of regions due to refill
regionsRefilled	uint	Region Refills Number of regions refilled
numPlabsFilled	ulong 17+	PLAB Fills Number of PLABs filled
directAllocated	ulong: bytes	Allocated (direct) Total memory allocated using direct allocation outside of PLABs
numDirectAllocated	ulong 17+	Direct allocations Number of direct allocations
failureUsed	ulong: bytes	Used (failure) Total memory occupied by objects in regions where evacuation failed
failureWaste	ulong: bytes	Wasted (failure) Total memory left unused in regions where evacuation failed

Examples 2

G1GC
G1GC

allocated	ulong: bytes	44040192
directAllocated	ulong: bytes	0
failureUsed	ulong: bytes	0
failureWaste	ulong: bytes	0
gcId	uint	39
numDirectAllocated	ulong	5
numPlabsFilled	ulong	7504122885671534260
regionEndWaste	ulong: bytes	0
regionsRefilled	uint	21
undoWaste	ulong: bytes	0
used	ulong: bytes	44038320
wasted	ulong: bytes	1872

allocated	ulong: bytes	0
directAllocated	ulong: bytes	0
failureUsed	ulong: bytes	0
failureWaste	ulong: bytes	0
gcId	uint	17
numDirectAllocated	ulong	6147041496
numPlabsFilled	ulong	0
regionEndWaste	ulong: bytes	0
regionsRefilled	uint	0
undoWaste	ulong: bytes	0
used	ulong: bytes	0
wasted	ulong: bytes	0

G1HeapRegionType

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

G1 Heap Region Type No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
type	string	Type

Examples 2

G1GC
G1GC

Free

Old

G1YCType

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

G1 YC Type No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
type	string	Type

Examples 1

G1GC

Mixed

GCCause

GC Cause No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
cause	string	Cause

Examples 3

Allocation Failure

G1 Evacuation Pause

GCName

GC Name No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
name	string	Name

Examples 3

G1New

G1Old

ParallelScavenge

GCThresholdUpdater

GC Threshold Updater No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
updater	string	Updater

Examples 3

compute_new_size

GCWhen

GC When No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
when	string	When

Examples 3

Before GC

After GC

InflateCause

Inflation Cause No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
cause	string	Cause

MetadataType

Metadata Type No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
type	string	Type

Examples 3

Class

Metadata

Class

MetaspaceObjectType

Metaspace Object Type No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
type	string	Type

Examples 3

ConstMethod

ConstantPool

Method

MetaspaceSizes

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
committed	ulong: bytes	Committed Committed memory for this space
used	ulong: bytes	Used Bytes allocated by objects in the space
reserved	ulong: bytes	Reserved Reserved memory for this space

Examples 3

committed	ulong: bytes	3080192
reserved	ulong: bytes	1073741824
used	ulong: bytes	2830240

committed	ulong: bytes	23396352
reserved	ulong: bytes	67108864
used	ulong: bytes	23220816

committed	ulong: bytes	26476544
reserved	ulong: bytes	1140850688
used	ulong: bytes	26051056

Method

Java Method

Field	Type	Description
type	Class	Type Consider contributing a description to jfreventcollector.
name	Symbol	Name Consider contributing a description to jfreventcollector.
descriptor	Symbol	Descriptor Consider contributing a description to jfreventcollector.
modifiers	int	Access Modifiers
hidden	boolean	Hidden

Module

Module No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
name	Symbol	Name Consider contributing a description to jfreventcollector.
version	Symbol	Version Consider contributing a description to jfreventcollector.
location	Symbol	Location Consider contributing a description to jfreventcollector.
classLoader	ClassLoader	Class Loader Consider contributing a description to jfreventcollector.

NarrowOopMode

Narrow Oop Mode No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
mode	string	Mode

Examples 3

Zero based

NetworkInterfaceName

Network Interface No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
networkInterface	string	Network Interface Network Interface Name

Examples 3

en0

lo0

ObjectSpace

Appearing in: ParallelGC

Missing in: G1GC, SerialGC, ShenandoahGC, ZGC

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
start	ulong: address	Start Address Start address of the space
end	ulong: address	End Address End address of the space
used	ulong: bytes	Used Bytes allocated by objects in the space
size	ulong: bytes	Size Size of the space

Examples 3

end	ulong: address	30407131136
size	ulong: bytes	342360064
start	ulong: address	30064771072
used	ulong: bytes	176957048

end	ulong: address	34353971200
size	ulong: bytes	213909504
start	ulong: address	34140061696
used	ulong: bytes	3695728

end	ulong: address	33919860736
size	ulong: bytes	991428608
start	ulong: address	32928432128
used	ulong: bytes	991428608

OldObject

Old Object No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
address	ulong: address	Memory Address
type	Class	Java Class
description	string	Object Description Object description
referrer	Reference	Referrer Object Object referencing this object

Examples 3

address	ulong: address	31577641576
description	string	null
referrer	Reference	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/lang/Class
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang

address	ulong: address	30180806312
description	string	null
referrer	Reference	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	48
name	string	java/util/concurrent/SynchronousQueue$TransferStack$SNode
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/concurrent

address	ulong: address	30176358424
description	string	null
referrer	Reference	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	0
name	string	[Ljava/util/concurrent/ForkJoinTask;
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/concurrent

OldObjectArray

Old Object Array No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
size	int	Array Size Size of array
index	int	Index Index in the array

OldObjectField

Old Object Field No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
name	string	Field Name of field
modifiers	short	Field Modifiers Field modifiers

OldObjectGcRoot

GC Root No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
description	string	Root Description Root information
system	OldObjectRootSystem	System The subsystem of origin for the root
type	OldObjectRootType	Type The root type

Examples 3

null

OldObjectRootSystem

GC Root System No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
system	string	System

OldObjectRootType

GC Root Type No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
type	string	Type

Package

Package No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
name	Symbol	Name Consider contributing a description to jfreventcollector.
module	Module	Module Consider contributing a description to jfreventcollector.
exported	boolean	Exported

Reference

Reference No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
array	OldObjectArray	Array Information Array or null if it is not an array
field	OldObjectField	Field Information Field or null if it is an array
object	OldObject	Object Object holder for this reference
skip	int	Skip Value The object is this many hops away

Examples 3

null

ReferenceType

Reference Type No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
type	string	Type

Examples 3

Phantom reference

Soft reference

ShenandoahHeapRegionState

Appearing in: ShenandoahGC

Missing in: G1GC, ParallelGC, SerialGC, ZGC

Shenandoah Heap Region State No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
state	string	State

Examples 2

ShenandoahGC
ShenandoahGC

Empty Committed

Trash

StackFrame

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
method	Method	Java Method
lineNumber	int	Line Number
bytecodeIndex	int	Bytecode Index
type	FrameType	Frame Type

Examples 3

bytecodeIndex	int	93
lineNumber	int	143
method	Method
descriptor	string	(J)V
hidden	boolean	false
modifiers	int	20
name	string	ensureCapacity
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/stream/SpinedBuffer
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/stream
type	FrameType	Interpreted

bytecodeIndex	int	22
lineNumber	int	2032
method	Method
descriptor	string	(Ljava/util/Locale;)Ljava/text/DecimalFormatSymbols;
hidden	boolean	false
modifiers	int	10
name	string	getDecimalFormatSymbols
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/util/Formatter
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util
type	FrameType	Interpreted

bytecodeIndex	int	0
lineNumber	int	70
method	Method
descriptor	string	()V
hidden	boolean	false
modifiers	int	8
name	string	<clinit>
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	sun/util/resources/LocaleData
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	sun/util/resources
type	FrameType	Interpreted

StackTrace

Stacktrace No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
truncated	boolean	Truncated
frames array	StackFrame struct	Stack Frames

Symbol

Symbol No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
string	string	String

Thread

Thread No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
osName	string	OS Thread Name
osThreadId	long	OS Thread Id
javaName	string	Java Thread Name
javaThreadId	long	Java Thread Id
group	ThreadGroup	Java Thread Group

ThreadGroup

Thread Group No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
parent	ThreadGroup	Parent Consider contributing a description to jfreventcollector.
name	string	Name

Examples 3

name	string	system
parent	ThreadGroup	null

null

ThreadState

Java Thread State

Field	Type	Description
name	string	Name

Examples 3

STATE_RUNNABLE

VMOperationType

VM Operation Type No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
type	string	Type

Examples 3

GC_HeapInspection

GenCollectForAllocation

G1CollectForAllocation

VirtualSpace

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
start	ulong: address	Start Address Start address of the virtual space
committedEnd	ulong: address	Committed End Address End address of the committed memory for the virtual space
committedSize	ulong: bytes	Committed Size Size of the committed memory for the virtual space
reservedEnd	ulong: address	Reserved End Address End address of the reserved memory for the virtual space
reservedSize	ulong: bytes	Reserved Size Size of the reserved memory for the virtual space

Examples 3

committedEnd	ulong: address	30389305344
committedSize	ulong: bytes	324534272
reservedEnd	ulong: address	34359738368
reservedSize	ulong: bytes	4294967296
start	ulong: address	30064771072

committedEnd	ulong: address	30407131136
committedSize	ulong: bytes	342360064
reservedEnd	ulong: address	32928432128
reservedSize	ulong: bytes	2863661056
start	ulong: address	30064771072

committedEnd	ulong: address	31811698688
committedSize	ulong: bytes	1746927616
reservedEnd	ulong: address	34359738368
reservedSize	ulong: bytes	4294967296
start	ulong: address	30064771072

ZPageTypeType

15+

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Z Page Type No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
type	string	Type

Examples 1

Small

ZStatisticsCounterType

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Z Statistics Counter No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
counter	string	Counter

Examples 1

Allocation Rate

ZStatisticsSamplerType

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Z Statistics Sampler No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field	Type	Description
sampler	string	Sampler

Examples 1

Concurrent Roots ClassLoaderDataGraph

XML Content Types

address

Annotation: jdk.jfr.MemoryAddress

Examples 3

4649009152

8558223360

bits-per-second

Annotation: jdk.jfr.DataAmount(BITS), jdk.jfr.Frequency

Examples 3

2403656

3912400

10730984

bytes

Annotation: jdk.jfr.DataAmount(BYTES)

Examples 3

17179869184

16003137536

bytes-per-second

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Annotation: jdk.jfr.DataAmount(BYTES), jdk.jfr.Frequency

Examples 2

G1GC
G1GC

6.647098700594988E7

1.9214995359726005E9

certificateId

Annotation: jdk.jfr.events.CertificateId

epochmillis

Annotation: jdk.jfr.Timestamp(MILLISECONDS_SINCE_EPOCH)

Examples 3

1702902685041

1702902684442

-9223372036854775808

hertz

Annotation: jdk.jfr.Frequency

Examples 3

1000000000

33222.207

1000000000

microseconds

17+

Annotation: jdk.jfr.Timespan(MICROSECONDS)

millis

Annotation: jdk.jfr.Timespan(MILLISECONDS)

Examples 3

736612750

75168554750

725916750

nanos

Annotation: jdk.jfr.Timespan(NANOSECONDS)

Examples 3

30000000

-9223372036854775808

500000000

percentage

Annotation: jdk.jfr.Percentage

Examples 3

0.0058880956

0.47368422

0.45

tickspan

Annotation: jdk.jfr.Timespan(TICKS)

Examples 3

626709

21154750

16033886334

tickstamp

Annotation: jdk.jfr.Timestamp(TICKS)

XML Types

Class

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.


Parameter Type	const Klass*
Field Type	const Klass*
Java Type	java.lang.Class

Examples 3

null

classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/ResourceBundle$Control
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util

ClassLoader

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.


Parameter Type	const ClassLoaderData*
Field Type	const ClassLoaderData*

Examples 3

name	string	bootstrap
type	Class	null

name	string	bootstrap
type	Class	null

name	string	bootstrap
type	Class	null

Method

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.


Parameter Type	const Method*
Field Type	const Method*

Examples 3

descriptor	string	(Ljava/util/Locale;)Ljava/text/DecimalFormatSymbols;
hidden	boolean	false
modifiers	int	10
name	string	getDecimalFormatSymbols
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/util/Formatter
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util

descriptor	string	(J)V
hidden	boolean	false
modifiers	int	2
name	string	putUncheckedLong
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	jdk/jfr/internal/event/EventWriter
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/jdk.jfr
name	string	jdk.jfr
version	string	21.0.1
name	string	jdk/jfr/internal/event

descriptor	string	()V
hidden	boolean	false
modifiers	int	8
name	string	<clinit>
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	sun/util/resources/LocaleData
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	sun/util/resources

Module

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.


Parameter Type	const ModuleEntry*
Field Type	const ModuleEntry*

Examples 3

classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.logging
name	string	java.logging
version	string	21.0.1

classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1

classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1

Package

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.


Parameter Type	const PackageEntry*
Field Type	const PackageEntry*

Examples 3

exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/text

exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util

exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	sun/util/resources

StackTrace

15+

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.


Parameter Type	u8
Field Type	u8
Java Type	jdk.types.StackTrace

Examples 3

frames	StackFrame
bytecodeIndex	int	93
lineNumber	int	143
method	Method
descriptor	string	(J)V
hidden	boolean	false
modifiers	int	20
name	string	ensureCapacity
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/stream/SpinedBuffer
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/stream
type	FrameType	Interpreted
		…
truncated	boolean	false

frames	StackFrame
bytecodeIndex	int	22
lineNumber	int	2032
method	Method
descriptor	string	(Ljava/util/Locale;)Ljava/text/DecimalFormatSymbols;
hidden	boolean	false
modifiers	int	10
name	string	getDecimalFormatSymbols
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/util/Formatter
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util
type	FrameType	Interpreted
		…
truncated	boolean	false

frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	70
method	Method
descriptor	string	()V
hidden	boolean	false
modifiers	int	8
name	string	<clinit>
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	sun/util/resources/LocaleData
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	sun/util/resources
type	FrameType	Interpreted
		…
truncated	boolean	false

Thread

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.


Parameter Type	u8
Field Type	u8
Java Type	java.lang.Thread

Examples 3

group	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	Service Thread
javaThreadId	long	12
osName	string	Service Thread
osThreadId	long	23043
virtual	boolean	false

group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	UCT-akka.actor.default-dispatcher-11
javaThreadId	long	133
osName	string	UCT-akka.actor.default-dispatcher-11
osThreadId	long	45063
virtual	boolean	false

group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	UCT-akka.actor.default-dispatcher-16
javaThreadId	long	138
osName	string	UCT-akka.actor.default-dispatcher-16
osThreadId	long	82955
virtual	boolean	false

Ticks

unsigned

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.


Parameter Type	const Ticks&
Field Type	Ticks
Java Type	long
Content Type	tickstamp

Examples 3

93744122083

61966638875

6649468250

Tickspan

unsigned

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.


Parameter Type	const Tickspan&
Field Type	Tickspan
Java Type	long
Content Type	tickspan

boolean


Parameter Type	bool
Field Type	bool
Java Type	boolean

Examples 3

false

true

byte


Parameter Type	s1
Field Type	s1
Java Type	byte

char


Parameter Type	char
Field Type	char
Java Type	char

double


Parameter Type	double
Field Type	double
Java Type	double

Examples 3

0.0

float


Parameter Type	float
Field Type	float
Java Type	float

Examples 3

1.6117458

2.5381775

2.5977247

int


Parameter Type	s4
Field Type	s4
Java Type	int

Examples 3

1537

long


Parameter Type	s8
Field Type	s8
Java Type	long

Examples 3

21922

23043

short


Parameter Type	s2
Field Type	s2
Java Type	short

string


Parameter Type	const char*
Field Type	const char*
Java Type	java.lang.String

Examples 3

bootstrap

java/util/ResourceBundle$Control

java/util

ubyte

unsigned


Parameter Type	u1
Field Type	u1
Java Type	byte

Examples 3

uint

unsigned


Parameter Type	unsigned
Field Type	unsigned
Java Type	int

Examples 3

ulong

unsigned


Parameter Type	u8
Field Type	u8
Java Type	long

Examples 3

ushort

unsigned


Parameter Type	u2
Field Type	u2
Java Type	short

Examples 3