Introduction

The following are the events for the OpenJDK 17 (jdk-17.0.12+6, 10-July-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	4168
flushId	ulong	74
size	ulong: bytes	1182006
startTime	long: millis	76320043292

elements	ulong	1109
flushId	ulong	85
size	ulong: bytes	844972
startTime	long: millis	93418969833

elements	ulong	2589
flushId	ulong	37
size	ulong: bytes	380413
startTime	long: millis	39423712792

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	15735901042

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	58731282750

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	49
name	string	threshold
stackTrace	StackTrace	null
startTime	long: millis	669832834
value	string	0 ms

id	long	38
name	string	enabled
stackTrace	StackTrace	null
startTime	long: millis	360834042
value	string	true

id	long	8
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_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	52080815958

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	22148519000

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	422523083

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.name
startTime	long: millis	30519032542
value	string	OpenJDK 64-Bit Server VM

key	string	java.vm.specification.version
startTime	long: millis	36095836209
value	string	21

key	string	java.vm.vendor
startTime	long: millis	60343487417
value	string	Eclipse Adoptium

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/Formatter$Conversion
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
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	106
lineNumber	int	2839
method	Method
descriptor	string	(Ljava/lang/String;)Ljava/util/List;
hidden	boolean	false
modifiers	int	8
name	string	parse
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	458996625

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/Collections$SynchronizedCollection
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
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	2407
method	Method
descriptor	string	(Ljava/util/Set;Ljava/lang/Object;)Ljava/util/Set;
hidden	boolean	false
modifiers	int	8
name	string	synchronizedSet
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/Collections
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	378631375

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	1057
name	string	java/text/spi/DecimalFormatSymbolsProvider
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/spi
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	181
method	Method
descriptor	string	(Ljava/util/Locale;)Ljava/text/DecimalFormatSymbols;
hidden	boolean	false
modifiers	int	25
name	string	getInstance
type	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
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	726092834

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	sun/util/cldr/CLDRLocaleProviderAdapter
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/cldr
definingClassLoader	ClassLoader
name	string	bootstrap
type	Class	null
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	(Ljava/lang/String;ZLjava/lang/ClassLoader;Ljava/lang/Class;)Ljava/lang/Class;
hidden	boolean	false
modifiers	int	266
name	string	forName0
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	466517792

definedClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/jar/Manifest$FastInputStream
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
definingClassLoader	ClassLoader
name	string	bootstrap
type	Class	null
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	287
method	Method
descriptor	string	(Ljava/io/InputStream;Ljava/lang/String;)V
hidden	boolean	false
modifiers	int	2
name	string	read
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/jar/Manifest
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
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	699156042

definedClass	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
definingClassLoader	ClassLoader
name	string	bootstrap
type	Class	null
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	5
lineNumber	int	55
method	Method
descriptor	string	(Ljava/util/jar/JarVerifier;Ljava/io/InputStream;Ljava/lang/String;)V
hidden	boolean	false
modifiers	int	0
name	string	<init>
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/jar/Manifest
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
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	380908250

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	3889585042
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+0x0000000800361268/1412564235
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

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	4558742958
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	33
name	string	org/apache/spark/storage/DefaultTopologyMapper
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/storage

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	5994071625
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	33
name	string	org/apache/spark/network/util/JavaUtils
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/network/util

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	0
codeBlobType	CodeBlobType	CodeHeap 'non-profiled nmethods'
entryCount	int	4406
fullCount	int	0
methodCount	int	4406
reservedTopAddress	ulong: address	4771921920
startAddress	ulong: address	4649009152
startTime	long: millis	78021702000
unallocatedCapacity	ulong: bytes	112612096

adaptorCount	int	625
codeBlobType	CodeBlobType	CodeHeap 'non-nmethods'
entryCount	int	716
fullCount	int	0
methodCount	int	0
reservedTopAddress	ulong: address	4610097152
startAddress	ulong: address	4604248064
startTime	long: millis	40031139833
unallocatedCapacity	ulong: bytes	4357504

adaptorCount	int	0
codeBlobType	CodeBlobType	CodeHeap 'non-profiled nmethods'
entryCount	int	1777
fullCount	int	0
methodCount	int	1777
reservedTopAddress	ulong: address	5217714176
startAddress	ulong: address	5094801408
startTime	long: millis	17899843125
unallocatedCapacity	ulong: bytes	119288192

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	63027547542

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	17899844542

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	2000
compileId	uint	14026
compileLevel	ushort	3
compiler	CompilerType	c1
inlinedBytes	ulong: bytes	52
isOsr	boolean	false
method	Method
descriptor	string	(IIII)V
hidden	boolean	false
modifiers	int	20
name	string	checkSrcIndex
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	1057
name	string	io/netty/buffer/AbstractByteBuf
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/netty/buffer
startTime	long: millis	27786958709
succeded	boolean	true

codeSize	ulong: bytes	12160
compileId	uint	6539
compileLevel	ushort	4
compiler	CompilerType	c2
inlinedBytes	ulong: bytes	2233
isOsr	boolean	false
method	Method
descriptor	string	()Z
hidden	boolean	false
modifiers	int	17
name	string	exec
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	1057
name	string	akka/dispatch/Mailbox
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/dispatch
startTime	long: millis	10792586625
succeded	boolean	true

codeSize	ulong: bytes	4976
compileId	uint	15169
compileLevel	ushort	4
compiler	CompilerType	c2
inlinedBytes	ulong: bytes	767
isOsr	boolean	false
method	Method
descriptor	string	(Ljava/lang/Object;Ljava/lang/Class;Ljava/lang/String;)Lio/netty/util/internal/TypeParameterMatcher;
hidden	boolean	false
modifiers	int	9
name	string	find
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	1057
name	string	io/netty/util/internal/TypeParameterMatcher
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/netty/util/internal
startTime	long: millis	34940761917
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	3706
failureMessage	string	concurrent class loading
startTime	long: millis	3613493750

compileId	uint	22775
failureMessage	string	concurrent class loading
startTime	long: millis	57760414792

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	5
callee	CalleeMethod
descriptor	string	(Ljava/lang/StringBuilder;)V
name	string	<init>
type	string	java/lang/String
caller	Method
descriptor	string	()Ljava/lang/String;
hidden	boolean	false
modifiers	int	1
name	string	toString
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/lang/StringBuilder
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
compileId	uint	1455
message	string	inline
startTime	long: millis	414686042
succeeded	boolean	true

bci	int	24
callee	CalleeMethod
descriptor	string	(II)I
name	string	min
type	string	java/lang/Math
caller	Method
descriptor	string	([BII)[B
hidden	boolean	false
modifiers	int	10
name	string	copyOfRangeByte
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
compileId	uint	1413
message	string	inline
startTime	long: millis	359635750
succeeded	boolean	true

bci	int	43
callee	CalleeMethod
descriptor	string	(I)C
name	string	charAt
type	string	java/lang/String
caller	Method
descriptor	string	(Ljava/lang/String;)V
hidden	boolean	false
modifiers	int	2
name	string	putStringValue
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	1497
message	string	inline
startTime	long: millis	671543709
succeeded	boolean	true

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	make_not_entrant
bci	int	58
compileId	uint	2623
compiler	CompilerType	c2
instruction	Bytecode	invokestatic
lineNumber	int	1319
method	Method
descriptor	string	([Ljava/lang/Object;)[Ljava/lang/Object;
hidden	boolean	false
modifiers	int	1
name	string	toArray
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/ArrayList$SubList
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util
reason	DeoptimizationReason	intrinsic_or_type_checked_inlining
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	58
lineNumber	int	1319
method	Method
descriptor	string	([Ljava/lang/Object;)[Ljava/lang/Object;
hidden	boolean	false
modifiers	int	1
name	string	toArray
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/ArrayList$SubList
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	1651701000

action	DeoptimizationAction	reinterpret
bci	int	1
compileId	uint	1356
compiler	CompilerType	c2
instruction	Bytecode	ifnonnull
lineNumber	int	338
method	Method
descriptor	string	(Ljava/lang/Object;)I
hidden	boolean	false
modifiers	int	24
name	string	hash
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
reason	DeoptimizationReason	unstable_if
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	1
lineNumber	int	338
method	Method
descriptor	string	(Ljava/lang/Object;)I
hidden	boolean	false
modifiers	int	24
name	string	hash
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	430511333

action	DeoptimizationAction	reinterpret
bci	int	13
compileId	uint	3006
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	1793830792

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	20060
invalidatedCount	int	0
nmethodCodeSize	ulong: bytes	23774560
nmethodsSize	ulong: bytes	37307976
osrBytesCompiled	ulong: bytes	0
osrCompileCount	int	184
peakTimeSpent	long: millis	1360
standardBytesCompiled	ulong: bytes	0
standardCompileCount	int	19876
startTime	long: millis	82395567917
totalTimeSpent	long: millis	64547

bailoutCount	int	2
compileCount	int	2954
invalidatedCount	int	0
nmethodCodeSize	ulong: bytes	3322960
nmethodsSize	ulong: bytes	4919968
osrBytesCompiled	ulong: bytes	0
osrCompileCount	int	38
peakTimeSpent	long: millis	188
standardBytesCompiled	ulong: bytes	0
standardCompileCount	int	2916
startTime	long: millis	2611275417
totalTimeSpent	long: millis	2276

bailoutCount	int	3
compileCount	int	8410
invalidatedCount	int	0
nmethodCodeSize	ulong: bytes	10036696
nmethodsSize	ulong: bytes	15931264
osrBytesCompiled	ulong: bytes	0
osrCompileCount	int	100
peakTimeSpent	long: millis	953
standardBytesCompiled	ulong: bytes	0
standardCompileCount	int	8310
startTime	long: millis	29333246833
totalTimeSpent	long: millis	18783

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	30586816333
threadCount	int	4
tieredCompilation	boolean	true

startTime	long: millis	364774125
threadCount	int	4
tieredCompilation	boolean	true

startTime	long: millis	27602494875
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	12863170084
value	int	-1

name	string	VMThreadPriority
origin	FlagValueOrigin	Default
startTime	long: millis	52082151458
value	int	-1

name	string	JavaPriority8_To_OSPriority
origin	FlagValueOrigin	Default
startTime	long: millis	39268374917
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	ParallelGCThreads
origin	FlagValueOrigin	Default
startTime	long: millis	17899853958
value	uint	8

name	string	SharedSymbolTableBucketSize
origin	FlagValueOrigin	Default
startTime	long: millis	84416230875
value	uint	4

name	string	G1RemSetArrayOfCardsEntriesBase
origin	FlagValueOrigin	Default
startTime	long: millis	50917396750
value	uint	8

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	MultiArrayExpandLimit
origin	FlagValueOrigin	Default
startTime	long: millis	364807042
value	long	6

name	string	CIStopOSR
origin	FlagValueOrigin	Default
startTime	long: millis	676084625
value	long	2147483647

name	string	Tier3LoadFeedback
origin	FlagValueOrigin	Default
startTime	long: millis	423475208
value	long	5

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	TargetPLABWastePct
origin	FlagValueOrigin	Default
startTime	long: millis	676112500
value	ulong	10

name	string	YoungGenerationSizeSupplement
origin	FlagValueOrigin	Default
startTime	long: millis	364825000
value	ulong	80

name	string	DeoptimizeObjectsALotInterval
origin	FlagValueOrigin	Default
startTime	long: millis	423584500
value	ulong	5

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	ZCollectionIntervalMinor
origin	FlagValueOrigin	Default
startTime	long: millis	15845390792
value	double	-1.0

name	string	ZAllocationSpikeTolerance
origin	FlagValueOrigin	Default
startTime	long: millis	27602535834
value	double	2.0

name	string	ZFragmentationLimit
origin	FlagValueOrigin	Default
startTime	long: millis	30586857958
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	EliminateBlocks
origin	FlagValueOrigin	Default
startTime	long: millis	676154334
value	boolean	true

name	string	PrintCFGToFile
origin	FlagValueOrigin	Default
startTime	long: millis	423601375
value	boolean	false

name	string	UseFastNewObjectArray
origin	FlagValueOrigin	Default
startTime	long: millis	364841708
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	TraceJVMTI
origin	FlagValueOrigin	Default
startTime	long: millis	22150099292
value	string	null

name	string	CompileCommand
origin	FlagValueOrigin	Default
startTime	long: millis	364878958
value	string

name	string	TraceJVMTI
origin	FlagValueOrigin	Default
startTime	long: millis	17899931000
value	string	null

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	10
longestPause	Tickspan	3593250
name	GCName	ParallelScavenge
startTime	long: millis	1758977458
sumOfPauses	Tickspan	3593250

cause	GCCause	G1 Evacuation Pause
gcId	uint	89
longestPause	Tickspan	2163042
name	GCName	G1New
startTime	long: millis	31189713875
sumOfPauses	Tickspan	2163042

cause	GCCause	Allocation Failure
gcId	uint	16
longestPause	Tickspan	5648250
name	GCName	DefNew
startTime	long: millis	1771866583
sumOfPauses	Tickspan	5648250

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	67307684958

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	51149593917

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	25683231583

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	92
startTime	long: millis	64383837083

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	12
startTime	long: millis	1668033583
tenuringThreshold	uint	15

gcId	uint	99
startTime	long: millis	35072889875
tenuringThreshold	uint	15

gcId	uint	83
startTime	long: millis	61468069708
tenuringThreshold	uint	15

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	103
startTime	long: millis	36512058500

gcId	uint	314
startTime	long: millis	74131936208

gcId	uint	80
startTime	long: millis	60479174417

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	89
startTime	long: millis	31189713875
type	G1YCType	Normal

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	ParallelOld
parallelGCThreads	uint	8
pauseTarget	long: millis	-9223372036854775808
startTime	long: millis	79064862167
usesDynamicGCThreads	boolean	true
youngCollector	GCName	ParallelScavenge

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	76136276083
usesDynamicGCThreads	boolean	true
youngCollector	GCName	DefNew

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	692395334
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	16561208250

initialTenuringThreshold	ubyte	7
maxTenuringThreshold	ubyte	15
startTime	long: millis	18250634375

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	13055583875
tlabRefillWasteLimit	ulong: bytes	64
usesTLABs	boolean	true

minTLABSize	ulong: bytes	2048
startTime	long: millis	16561210125
tlabRefillWasteLimit	ulong: bytes	64
usesTLABs	boolean	true

minTLABSize	ulong: bytes	2048
startTime	long: millis	39413198375
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	27650271542
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

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	60476333958
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	2575302656
minSize	ulong: bytes	1363144
newRatio	uint	2
startTime	long: millis	13055587417

maxSize	ulong: bytes	1431633920
minSize	ulong: bytes	89456640
newRatio	uint	2
startTime	long: millis	88354590458

maxSize	ulong: bytes	1431306240
minSize	ulong: bytes	89128960
newRatio	uint	2
startTime	long: millis	30586925000

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	70
gcTime	long: millis	4
pauseTarget	long: millis	200
startTime	long: millis	22743352125
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	25144
gcId	uint	1
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
startTime	long: millis	865943958
totalSize	ulong: bytes	603456

count	long	561
gcId	uint	16
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	4573757000
totalSize	ulong: bytes	1506072

count	long	9549
gcId	uint	1
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
startTime	long: millis	684981625
totalSize	ulong: bytes	229176

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	8381843375
statistics	G1EvacuationStatistics
allocated	ulong: bytes	25165824
directAllocated	ulong: bytes	0
failureUsed	ulong: bytes	0
failureWaste	ulong: bytes	0
gcId	uint	30
regionEndWaste	ulong: bytes	0
regionsRefilled	uint	12
undoWaste	ulong: bytes	0
used	ulong: bytes	25159368
wasted	ulong: bytes	6456

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	29724024459
statistics	G1EvacuationStatistics
allocated	ulong: bytes	0
directAllocated	ulong: bytes	0
failureUsed	ulong: bytes	0
failureWaste	ulong: bytes	0
gcId	uint	85
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	422908616
gcId	uint	116
lastMarkingDuration	long: millis	880
recentAllocationRate	double: bytes-per-second	8.340350789552855E8
recentMutatorAllocationSize	ulong: bytes	177209344
recentMutatorDuration	long: millis	212
startTime	long: millis	40450125375
targetOccupancy	ulong: bytes	729808896
threshold	ulong: bytes	328414003
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	769654784
currentOccupancy	ulong: bytes	183094752
gcId	uint	69
ihopTargetOccupancy	ulong: bytes	1219284172
predictedAllocationRate	double: bytes-per-second	1.5955827870525086E9
predictedMarkingDuration	long: millis	338
predictionActive	boolean	false
startTime	long: millis	22586574459
threshold	ulong: bytes	577555660
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	8176
startTime	long: millis	1163666125
tenured	boolean	true
tenuringAge	uint	1

gcId	uint	6
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
objectSize	ulong: bytes	120
plabSize	ulong: bytes	23504
startTime	long: millis	1432132042
tenured	boolean	false
tenuringAge	uint	1

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

ParallelGC
G1GC

gcId	uint	7
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	131088
startTime	long: millis	1290479375
tenured	boolean	false
tenuringAge	uint	1

gcId	uint	41
objectClass	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
objectSize	ulong: bytes	262160
startTime	long: millis	11307373084
tenured	boolean	true
tenuringAge	uint	1

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	20
realTime	ulong: nanos	9999990
startTime	long: millis	1837505083
systemTime	ulong: nanos	0
userTime	ulong: nanos	10000000

gcId	uint	39
realTime	ulong: nanos	50000190
startTime	long: millis	9996121084
systemTime	ulong: nanos	10000000
userTime	ulong: nanos	320000000

gcId	uint	24
realTime	ulong: nanos	730000019
startTime	long: millis	13402946167
systemTime	ulong: nanos	219999999
userTime	ulong: nanos	380000000

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	96
size	ulong: bytes	2048
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	8
lineNumber	int	101
method	Method
descriptor	string	(Lio/netty/handler/codec/http2/Http2Stream;)V
hidden	boolean	false
modifiers	int	1
name	string	onStreamActive
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	32
name	string	io/netty/handler/codec/http2/DefaultHttp2LocalFlowController$1
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/netty/handler/codec/http2
type	FrameType	JIT compiled
		…
truncated	boolean	true
startTime	long: millis	33946942917

gcId	uint	68
size	ulong: bytes	80
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	17
lineNumber	int	49
method	Method
descriptor	string	(Lscala/collection/mutable/HashTable;)V
hidden	boolean	false
modifiers	int	9
name	string	$init$
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	1537
name	string	scala/collection/mutable/HashTable
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/mutable
type	FrameType	Inlined
		…
truncated	boolean	false
startTime	long: millis	49558438000

gcId	uint	50
size	ulong: bytes	40
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	230
method	Method
descriptor	string	(DDD)Lio/jenetics/DoubleGene;
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/DoubleGene
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	5210477792

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

SerialGC
G1GC

age	uint	11
gcId	uint	3
size	ulong: bytes	0
startTime	long: millis	1087485750

age	uint	9
gcId	uint	2
size	ulong: bytes	0
startTime	long: millis	914806917

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	Eden
index	uint	12
start	ulong: address	30089936896
startTime	long: millis	1553166709
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	292013
gcId	uint	69
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/HashMap$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
startTime	long: millis	8663866792
totalSize	ulong: bytes	9344416

count	long	420
gcId	uint	1
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	48
name	string	java/lang/invoke/MemberName
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/invoke
startTime	long: millis	684981625
totalSize	ulong: bytes	20160

count	long	248005
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	49
name	string	akka/actor/ChildActorPath
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	7936160

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	69
start	ulong: address	30209474560
startTime	long: millis	12822305209
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	17785543791
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	2097152
flushed	ulong: bytes	0
nonBlocking	boolean	false
segments	uint	1
size	ulong: bytes	2097152
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	80
method	Method
descriptor	string	(Ljava/lang/Object;)V
hidden	boolean	false
modifiers	int	17
name	string	add
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	1057
name	string	akka/dispatch/AbstractNodeQueue
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/dispatch
type	FrameType	Inlined
		…
truncated	boolean	false
startTime	long: millis	11799669000
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	1201668096
relocate	ulong: bytes	7253032
startTime	long: millis	36019573958
total	ulong: bytes	1472200704

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	0
relocate	ulong: bytes	0
startTime	long: millis	18055087250
total	ulong: bytes	14680064
type	ZPageTypeType	Large

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	Page Cache Hit L1
increment	ulong	1
startTime	long: millis	608895291
value	ulong	11

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	Uncommit
startTime	long: millis	1030574166
value	ulong	0

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	4
name	string	Concurrent Roots ClassLoaderDataGraph
startTime	long: millis	1663066708

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	30472697625
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	Empty Uncommitted
index	uint	2028
start	ulong: address	34317795328
startTime	long: millis	1286197625
to	ShenandoahHeapRegionState	Regular
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	24
start	ulong: address	30115102720
startTime	long: millis	363234167
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	38
heapSpace	VirtualSpace
committedEnd	ulong: address	30918311936
committedSize	ulong: bytes	853540864
reservedEnd	ulong: address	34359738368
reservedSize	ulong: bytes	4294967296
start	ulong: address	30064771072
heapUsed	ulong: bytes	336489408
startTime	long: millis	9730238667
when	GCWhen	After GC

gcId	uint	34
heapSpace	VirtualSpace
committedEnd	ulong: address	31628197888
committedSize	ulong: bytes	1563426816
reservedEnd	ulong: address	34359738368
reservedSize	ulong: bytes	4294967296
start	ulong: address	30064771072
heapUsed	ulong: bytes	1375833800
startTime	long: millis	20989635708
when	GCWhen	Before GC

gcId	uint	4
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	59922072
startTime	long: millis	1155140083
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	2359296
reserved	ulong: bytes	1073741824
used	ulong: bytes	2293712
dataSpace	MetaspaceSizes
committed	ulong: bytes	19660800
reserved	ulong: bytes	67108864
used	ulong: bytes	19592184
gcId	uint	1
gcThreshold	ulong: bytes	22020096
metaspace	MetaspaceSizes
committed	ulong: bytes	22020096
reserved	ulong: bytes	1140850688
used	ulong: bytes	21885896
startTime	long: millis	871606500
when	GCWhen	After GC

classSpace	MetaspaceSizes
committed	ulong: bytes	3735552
reserved	ulong: bytes	1073741824
used	ulong: bytes	3547072
dataSpace	MetaspaceSizes
committed	ulong: bytes	28049408
reserved	ulong: bytes	67108864
used	ulong: bytes	27921304
gcId	uint	23
gcThreshold	ulong: bytes	38469632
metaspace	MetaspaceSizes
committed	ulong: bytes	31784960
reserved	ulong: bytes	1140850688
used	ulong: bytes	31468376
startTime	long: millis	5930033750
when	GCWhen	Before 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	13
gcThreshold	ulong: bytes	38338560
metaspace	MetaspaceSizes
committed	ulong: bytes	23855104
reserved	ulong: bytes	1140850688
used	ulong: bytes	23531968
startTime	long: millis	2072712917
when	GCWhen	Before 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	34066137088
size	ulong: bytes	1137704960
start	ulong: address	32928432128
used	ulong: bytes	77345760
fromSpace	ObjectSpace
end	ulong: address	34172043264
size	ulong: bytes	105906176
start	ulong: address	34066137088
used	ulong: bytes	105644208
gcId	uint	27
oldObjectSpace	ObjectSpace
end	ulong: address	30407131136
size	ulong: bytes	342360064
start	ulong: address	30064771072
used	ulong: bytes	270464288
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	17017258542
toSpace	ObjectSpace
end	ulong: address	34359738368
size	ulong: bytes	158334976
start	ulong: address	34201403392
used	ulong: bytes	0
when	GCWhen	Before GC
youngSpace	VirtualSpace
committedEnd	ulong: address	34359738368
committedSize	ulong: bytes	1431306240
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	1119879168
edenUsedSize	ulong: bytes	1117782016
gcId	uint	49
numberOfRegions	uint	1060
startTime	long: millis	15931217042
survivorUsedSize	ulong: bytes	123731968
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	139067392
oldValue	ulong: bytes	129236992
startTime	long: millis	36565660125
updater	GCThresholdUpdater	compute_new_size

newValue	ulong: bytes	101711872
oldValue	ulong: bytes	73072640
startTime	long: millis	38731090875
updater	GCThresholdUpdater	compute_new_size

newValue	ulong: bytes	143196160
oldValue	ulong: bytes	142802944
startTime	long: millis	56772787583
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	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

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

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	5
humongousChunks	ulong	0
humongousChunksTotalSize	ulong: bytes	0
mediumChunks	ulong	0
mediumChunksTotalSize	ulong: bytes	0
metadataType	MetadataType	Metadata
smallChunks	ulong	0
smallChunksTotalSize	ulong: bytes	0
specializedChunks	ulong	0
specializedChunksTotalSize	ulong: bytes	0
startTime	long: millis	1175873083
when	GCWhen	After GC

gcId	uint	9
humongousChunks	ulong	0
humongousChunksTotalSize	ulong: bytes	0
mediumChunks	ulong	0
mediumChunksTotalSize	ulong: bytes	0
metadataType	MetadataType	Metadata
smallChunks	ulong	0
smallChunksTotalSize	ulong: bytes	0
specializedChunks	ulong	0
specializedChunksTotalSize	ulong: bytes	0
startTime	long: millis	1605761250
when	GCWhen	Before GC

gcId	uint	5
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	1187184083
when	GCWhen	After 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	89
name	string	GC Pause
startTime	long: millis	63970773375

gcId	uint	97
name	string	GC Pause
startTime	long: millis	34325674084

gcId	uint	85
name	string	GC Pause
startTime	long: millis	13155768500

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	25
name	string	Notify and keep alive finalizable
startTime	long: millis	6747483875

gcId	uint	27
name	string	Notify PhantomReferences
startTime	long: millis	1927782000

gcId	uint	18
name	string	Reference Processing
startTime	long: millis	6355874083

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	65
name	string	Phase 2: Determine work lists
startTime	long: millis	22108521917

gcId	uint	13
name	string	Notify and keep alive finalizable
startTime	long: millis	2098656917

gcId	uint	1
name	string	Weak Processing
startTime	long: millis	861514125

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	146
name	string	Trigger cleanups
startTime	long: millis	28652014917

gcId	uint	28
name	string	Notify PhantomReferences
startTime	long: millis	17307511750

gcId	uint	23
name	string	Trigger cleanups
startTime	long: millis	5997351917

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	30
name	string	Balance queues
startTime	long: millis	18065412167

gcId	uint	203
name	string	Balance queues
startTime	long: millis	58666577125

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	138
name	string	Concurrent Cleanup for Next Mark
startTime	long: millis	48005539042

gcId	uint	13
name	string	Concurrent Process Non-Strong References
startTime	long: millis	20187437375

gcId	uint	1
name	string	Concurrent Marking
startTime	long: millis	1196740333

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	179
name	string	Preclean SoftReferences
startTime	long: millis	53692441917

gcId	uint	42
name	string	ClassLoaderData
startTime	long: millis	60739271958

gcId	uint	10
name	string	ClassLoaderData
startTime	long: millis	18251947792

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	2
gcWorkerId	uint	1
name	string	Update Region States
startTime	long: millis	2588764833

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	445
gcId	uint	9
startTime	long: millis	1429201625
type	ReferenceType	Weak reference

count	ulong	0
gcId	uint	28
startTime	long: millis	1939114500
type	ReferenceType	Soft reference

count	ulong	0
gcId	uint	9
startTime	long: millis	1618227125
type	ReferenceType	Final 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 -1 if it is not an array
root	OldObjectGcRoot	GC Root Consider contributing a description to jfreventcollector.

Examples 3

allocationTime	Ticks	87097460333
arrayElements	int	64
lastKnownHeapUsage	ulong: bytes	124397272
object	OldObject
address	ulong: address	31611143120
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	11870537375
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	98967997708

allocationTime	Ticks	970728584
arrayElements	int	-2147483648
lastKnownHeapUsage	ulong: bytes	5198464
object	OldObject
address	ulong: address	30072030784
description	string	null
referrer	Reference	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/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
objectAge	Tickspan	77029796625
root	OldObjectGcRoot	null
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	285
lineNumber	int	1047
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	78000525209

allocationTime	Ticks	93744159333
arrayElements	int	-2147483648
lastKnownHeapUsage	ulong: bytes	117658120
object	OldObject
address	ulong: address	30180806120
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	322750917
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

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-1
javaThreadId	long	23
osName	string	ForkJoinPool.commonPool-worker-1
osThreadId	long	31751
virtual	boolean	false
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	31
lineNumber	int	163
method	Method
descriptor	string	(Ljava/util/Spliterator;Ljava/util/stream/Sink;)Z
hidden	boolean	false
modifiers	int	16
name	string	forEachWithCancel
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	1056
name	string	java/util/stream/IntPipeline
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	false
startTime	long: millis	1982656625
state	ThreadState	STATE_RUNNABLE

sampledThread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	ForkJoinPool.commonPool-worker-3
javaThreadId	long	33
osName	string	ForkJoinPool.commonPool-worker-3
osThreadId	long	26627
virtual	boolean	false
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	25
lineNumber	int	151
method	Method
descriptor	string	()Z
hidden	boolean	false
modifiers	int	1
name	string	isValid
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/DoubleGene
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	5085118208
state	ThreadState	STATE_RUNNABLE

sampledThread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	ForkJoinPool.commonPool-worker-7
javaThreadId	long	42
osName	string	ForkJoinPool.commonPool-worker-7
osThreadId	long	40707
virtual	boolean	false
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	-1
lineNumber	int	-1
method	Method
descriptor	string	(Ljava/lang/Object;)J
hidden	boolean	true
modifiers	int	1
name	string	applyAsLong
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	true
modifiers	int	4144
name	string	java.util.stream.Collectors$$Lambda+0x0000000800251df0/1063719949
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	2633383042
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	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[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	3077636459
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	8707
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	2245198208
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	3259785167
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	42
startTime	long: millis	5833021542
totalThreadCount	int	19

jniCriticalThreadCount	int	0
safepointId	ulong	85
startTime	long: millis	6996092333
totalThreadCount	int	48

jniCriticalThreadCount	int	0
safepointId	ulong	47
startTime	long: millis	7164512542
totalThreadCount	int	46

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	3
iterations	int	3
runningThreadCount	int	0
safepointId	ulong	25
startTime	long: millis	1560930208

initialThreadCount	int	4
iterations	int	3
runningThreadCount	int	0
safepointId	ulong	59
startTime	long: millis	8104731959

initialThreadCount	int	1
iterations	int	3
runningThreadCount	int	0
safepointId	ulong	45
startTime	long: millis	6764243333

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	35
startTime	long: millis	4255337583

safepointId	ulong	71
startTime	long: millis	8357942375

safepointId	ulong	14
startTime	long: millis	1168887833

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	24
startTime	long: millis	1876253375

name	string	updating inline caches
safepointId	ulong	82
startTime	long: millis	6402583208

name	string	updating inline caches
safepointId	ulong	76
startTime	long: millis	8909572667

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	55
startTime	long: millis	4056716750

safepointId	ulong	38
startTime	long: millis	2727328792

safepointId	ulong	85
startTime	long: millis	16762649250

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-1-worker-1
javaThreadId	long	39
osName	string	ForkJoinPool-1-worker-1
osThreadId	long	42763
virtual	boolean	false
operation	VMOperationType	ICBufferFull
safepoint	boolean	true
safepointId	ulong	38
startTime	long: millis	4707365792

blocking	boolean	true
caller	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	UCT-akka.actor.internal-dispatcher-3
javaThreadId	long	52
osName	string	UCT-akka.actor.internal-dispatcher-3
osThreadId	long	35079
virtual	boolean	false
operation	VMOperationType	ICBufferFull
safepoint	boolean	true
safepointId	ulong	62
startTime	long: millis	8122701209

blocking	boolean	true
caller	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	UCT-akka.actor.default-dispatcher-4
javaThreadId	long	43
osName	string	UCT-akka.actor.default-dispatcher-4
osThreadId	long	26895
virtual	boolean	false
operation	VMOperationType	GenCollectForAllocation
safepoint	boolean	true
safepointId	ulong	87
startTime	long: millis	7029818125

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	77999546542

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

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	4.352051
bucketCountMaximum	ulong	15
bucketCountStandardDeviation	float	2.1034112
bucketCountVariance	float	4.4243393
entryCount	ulong	142608
insertionRate	float	5909.958
removalRate	float	88.15976
startTime	long: millis	45308622083
totalFootprint	ulong: bytes	11769968

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	4.6469116
bucketCountMaximum	ulong	17
bucketCountStandardDeviation	float	2.17525
bucketCountVariance	float	4.731713
entryCount	ulong	152270
insertionRate	float	939.20593
removalRate	float	2.8816094
startTime	long: millis	52516316083
totalFootprint	ulong: bytes	13101104

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	0.3635559
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

bucketCount	ulong	65536
bucketCountAverage	float	0.3675537
bucketCountMaximum	ulong	6
bucketCountStandardDeviation	float	0.5988469
bucketCountVariance	float	0.35861766
entryCount	ulong	24088
insertionRate	float	92.834236
removalRate	float	3.566737
startTime	long: millis	41773560875
totalFootprint	ulong: bytes	2667552

bucketCount	ulong	65536
bucketCountAverage	float	0.4602356
bucketCountMaximum	ulong	6
bucketCountStandardDeviation	float	0.67385215
bucketCountVariance	float	0.45407674
entryCount	ulong	30162
insertionRate	float	587.75165
removalRate	float	125.00503
startTime	long: millis	73588887542
totalFootprint	ulong: bytes	3156016

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 12:47:28 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

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 12:45:49 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

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	7238750208
name	string	/usr/lib/swift/libswiftsimd.dylib
startTime	long: millis	364596583
topAddress	ulong: address	0

baseAddress	ulong: address	6564347904
name	string	/usr/lib/system/libsystem_blocks.dylib
startTime	long: millis	675848959
topAddress	ulong: address	0

baseAddress	ulong: address	6607503360
name	string	/System/Library/Frameworks/CoreAudio.framework/Versions/A/CoreAudio
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.base
name	string	java.base
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

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

requiredModule	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
source	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.instrument
name	string	java.instrument
version	string	21.0.1
startTime	long: millis	14998474333

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	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/duration
startTime	long: millis	14998523917
targetModule	Module	null

exportedPackage	Package
exported	boolean	true
module	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:/java.xml.crypto
name	string	java.xml.crypto
version	string	21.0.1
name	string	javax/xml/crypto/dsig/keyinfo
startTime	long: millis	16764024625
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	com/typesafe/config
startTime	long: millis	12401834834
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	scala-execution-context-global-58
javaThreadId	long	58
osName	string	scala-execution-context-global-58
osThreadId	long	38147
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	8074401084
thread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	scala-execution-context-global-64
javaThreadId	long	64
osName	string	scala-execution-context-global-64
osThreadId	long	37379
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-8
javaThreadId	long	127
osName	string	UCT-akka.actor.default-dispatcher-8
osThreadId	long	60423
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	12605246042
thread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	UCT-akka.actor.default-dispatcher-11
javaThreadId	long	131
osName	string	UCT-akka.actor.default-dispatcher-11
osThreadId	long	48135
virtual	boolean	false

parentThread	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	8707
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	10141040167
thread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	UCT-akka.actor.internal-dispatcher-2
javaThreadId	long	69
osName	string	UCT-akka.actor.internal-dispatcher-2
osThreadId	long	64771
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	13997492292
thread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	UCT-akka.actor.default-dispatcher-9
javaThreadId	long	131
osName	string	UCT-akka.actor.default-dispatcher-9
osThreadId	long	64263
virtual	boolean	false

startTime	long: millis	10752573958
thread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	UCT-akka.actor.internal-dispatcher-21
javaThreadId	long	96
osName	string	UCT-akka.actor.internal-dispatcher-21
osThreadId	long	42771
virtual	boolean	false

startTime	long: millis	19792871000
thread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	UCT-akka.actor.internal-dispatcher-2
javaThreadId	long	113
osName	string	UCT-akka.actor.internal-dispatcher-2
osThreadId	long	45319
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	7942725917
time	long: millis	10000000

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	9096030250
time	long: millis	10000000

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	9043663750
time	long: millis	8000000

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	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	6093701458
timeout	long: nanos	-9223372036854775808
until	long: epochmillis	-9223372036854775808

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	5229846750
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	8163884542
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	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-13
javaThreadId	long	64
osName	string	UCT-akka.actor.default-dispatcher-13
osThreadId	long	40195
virtual	boolean	false
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
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	Interpreted
		…
truncated	boolean	false
startTime	long: millis	7244060833

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-13
javaThreadId	long	55
osName	string	UCT-akka.actor.default-dispatcher-13
osThreadId	long	41219
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	7350910167

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-11
javaThreadId	long	133
osName	string	UCT-akka.actor.default-dispatcher-11
osThreadId	long	45063
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	11850464417

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	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
notifier	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	UCT-akka.actor.default-dispatcher-8
javaThreadId	long	242
osName	string	UCT-akka.actor.default-dispatcher-8
osThreadId	long	49939
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	16606877542
timedOut	boolean	false
timeout	long: millis	0

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
notifier	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	UCT-akka.actor.default-dispatcher-13
javaThreadId	long	87
osName	string	UCT-akka.actor.default-dispatcher-13
osThreadId	long	50179
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	8720863208
timedOut	boolean	false
timeout	long: millis	0

address	ulong: address	105553435830432
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-37
javaThreadId	long	366
osName	string	Thread-37
osThreadId	long	51467
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	75962799042
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	24
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	null
startTime	long: millis	925482084
tlabSize	ulong: bytes	27280

allocationSize	ulong: bytes	24
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	10
lineNumber	int	3863
method	Method
descriptor	string	([BII)[B
hidden	boolean	false
modifiers	int	10
name	string	copyOfRangeByte
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	1060529833
tlabSize	ulong: bytes	1342200

allocationSize	ulong: bytes	56
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/stream/ReferencePipeline$Head
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
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	false
startTime	long: millis	976323125
tlabSize	ulong: bytes	1433976

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	3605320
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
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	1
lineNumber	int	79
method	Method
descriptor	string	(I)[Ljava/lang/String;
hidden	boolean	false
modifiers	int	4106
name	string	lambda$resourceAsWords$2
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	org/renaissance/jdk/streams/JavaScrabble
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/renaissance/jdk/streams
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	1204583167

allocationSize	ulong: bytes	48088
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	2020575333

allocationSize	ulong: bytes	2232
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	15
lineNumber	int	3541
method	Method
descriptor	string	([BI)[B
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	JIT compiled
		…
truncated	boolean	false
startTime	long: millis	943655917

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	1145958708
weight	long: bytes	2097168

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	10
lineNumber	int	156
method	Method
descriptor	string	(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/ArrayList
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	JIT compiled
		…
truncated	boolean	false
startTime	long: millis	1573619709
weight	long: bytes	1045464

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	null
startTime	long: millis	379305750
weight	long: bytes	4576

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.invokeInterface(java.lang.Object, 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	795374500
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	'long java.lang.invoke.DirectMethodHandle$Holder.invokeSpecialIFC(java.lang.Object, 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	true
startTime	long: millis	29813450333
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	'java.lang.Object java.lang.invoke.DirectMethodHandle$Holder.invokeInterface(java.lang.Object, 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	474254083
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

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	50
host	string
port	int	52653
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	40768775667

address	string	127.0.0.1
bytesWritten	long: bytes	50
host	string
port	int	52296
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	37588030458

address	string	127.0.0.1
bytesWritten	long: bytes	52
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	69948594667

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.Map
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	659883042
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.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	584001708
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.NotImplementedError
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	938285125
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	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	8914
path	string	harness-133125-7262456833842592188/apache-spark/lib/hadoop-client-runtime-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	JIT compiled
		…
truncated	boolean	false
startTime	long: millis	3683197542

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

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	52
endOfStream	boolean	false
host	string
port	int	52294
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	38313909042
timeout	long: millis	0

address	string	127.0.0.1
bytesRead	long: bytes	169
endOfStream	boolean	false
host	string
port	int	56608
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	68850908834
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	339
activeCount	long	78
daemonCount	long	68
peakCount	long	85
startTime	long: millis	51975198709

accumulatedCount	long	304
activeCount	long	67
daemonCount	long	58
peakCount	long	67
startTime	long: millis	42441225792

accumulatedCount	long	245
activeCount	long	63
daemonCount	long	22
peakCount	long	84
startTime	long: millis	28092320542

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	2861
startTime	long: millis	1409394542
unloadedClassCount	long	0

loadedClassCount	long	15470
startTime	long: millis	49496715792
unloadedClassCount	long	3203

loadedClassCount	long	6961
startTime	long: millis	19194016042
unloadedClassCount	long	1609

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	17820240
chunkSize	ulong: bytes	18086912
classCount	long	2558
classLoader	ClassLoader	null
classLoaderData	ulong: address	105553170251776
hiddenBlockSize	ulong: bytes	208864
hiddenChunkSize	ulong: bytes	347136
hiddenClassCount	long	113
parentClassLoader	ClassLoader	null
startTime	long: millis	17892871750

blockSize	ulong: bytes	11904640
chunkSize	ulong: bytes	11916288
classCount	long	1472
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	105553176905600
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	51863913042

blockSize	ulong: bytes	5511160
chunkSize	ulong: bytes	5534720
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	105553151856544
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	36097326250

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	40
startTime	long: millis	17899740292
thread	Thread
group	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	C2 CompilerThread0
javaThreadId	long	10
osName	string	C2 CompilerThread0
osThreadId	long	23043
virtual	boolean	false

allocated	ulong: bytes	73804944
startTime	long: millis	12401705334
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	136
osName	string	UCT-akka.actor.default-dispatcher-14
osThreadId	long	35339
virtual	boolean	false

allocated	ulong: bytes	105279504
startTime	long: millis	14906032000
thread	Thread
group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	UCT-akka.actor.internal-dispatcher-2
javaThreadId	long	91
osName	string	UCT-akka.actor.internal-dispatcher-2
osThreadId	long	40455
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	6575097500
throwables	long	1962

stackTrace	StackTrace	null
startTime	long: millis	63145881584
throwables	long	216892

stackTrace	StackTrace	null
startTime	long: millis	88166377500
throwables	long	288849

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	89173598375

stackTrace	StackTrace	null
startTime	long: millis	45297031708

stackTrace	StackTrace	null
startTime	long: millis	46796275334

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	537709583
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	783480000
type	string	SecureRandom

algorithm	string	SHA
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	465287583
type	string	MessageDigest

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	policy.allowSystemProperty
stackTrace	StackTrace	null
startTime	long: millis	693429292
value	string	true

key	string	networkaddress.cache.negative.ttl
stackTrace	StackTrace	null
startTime	long: millis	437594375
value	string	10

key	string	policy.ignoreIdentityScope
stackTrace	StackTrace	null
startTime	long: millis	379185042
value	string	false

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	50916129792

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	88121844833

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	93733076333

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	75084798042

name	string	No virtualization detected
startTime	long: millis	15755086792

name	string	No virtualization detected
startTime	long: millis	62990156375

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	EDITOR
startTime	long: millis	672949625
value	string	nvim

key	string	HOMEBREW_CELLAR
startTime	long: millis	17889813583
value	string	/opt/homebrew/Cellar

key	string	INFOPATH
startTime	long: millis	364250500
value	string	/opt/homebrew/share/info:

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/symptomsd
pid	string	728
startTime	long: millis	16726490792

commandLine	string	/usr/sbin/systemstats
pid	string	542
startTime	long: millis	12397004584

commandLine	string	/usr/libexec/configd
pid	string	545
startTime	long: millis	14787855958

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	22148557209

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	75084818000

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	40019904833

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	78940177167

fastTimeAutoEnabled	boolean	false
fastTimeEnabled	boolean	false
fastTimeFrequency	long: hertz	1000000000
osFrequency	long: hertz	1000000000
startTime	long: millis	88121867708

fastTimeAutoEnabled	boolean	false
fastTimeEnabled	boolean	false
fastTimeFrequency	long: hertz	1000000000
osFrequency	long: hertz	1000000000
startTime	long: millis	36095849917

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	1.3231427E-5
jvmUser	float: percentage	0.0029297364
machineTotal	float: percentage	0.7346939
startTime	long: millis	65178642375

jvmSystem	float: percentage	2.2476098E-4
jvmUser	float: percentage	0.009866054
machineTotal	float: percentage	0.6466165
startTime	long: millis	24261768709

jvmSystem	float: percentage	7.6657825E-4
jvmUser	float: percentage	0.01133331
machineTotal	float: percentage	1.0
startTime	long: millis	80071259292

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	13427113542
system	float: percentage	1.2936193E-5
user	float: percentage	5.141668E-5

startTime	long: millis	11595339875
system	float: percentage	1.3850477E-4
user	float: percentage	0.0033107614

startTime	long: millis	11837954875
system	float: percentage	2.8243999E-4
user	float: percentage	0.001311321

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	45297165792
switchRate	float: hertz	46093.758

startTime	long: millis	63488582333
switchRate	float: hertz	9502.67

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	en0
readRate	long: bits-per-second	3701800
startTime	long: millis	58104078042
writeRate	long: bits-per-second	2656688

networkInterface	NetworkInterfaceName	utun5
readRate	long: bits-per-second	51736
startTime	long: millis	41764489750
writeRate	long: bits-per-second	16160

networkInterface	NetworkInterfaceName	lo0
readRate	long: bits-per-second	19033464
startTime	long: millis	98617564417
writeRate	long: bits-per-second	19033464

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	63027372959
totalSize	ulong: bytes	17179869184
usedSize	ulong: bytes	17029693440

startTime	long: millis	39596854458
totalSize	ulong: bytes	17179869184
usedSize	ulong: bytes	17094295552

startTime	long: millis	30586739000
totalSize	ulong: bytes	17179869184
usedSize	ulong: bytes	17037836288

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

invokestatic

ifnonnull

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	(II)I
name	string	min
type	string	java/lang/Math

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

descriptor	string	(I)C
name	string	charAt
type	string	java/lang/String

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-nmethods'

CodeHeap 'non-profiled 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

make_not_entrant

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

intrinsic_or_type_checked_inlining

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

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

JIT compiled

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
directAllocated	ulong: bytes	Allocated (direct) Total memory allocated using direct allocation outside of PLABs
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	0
directAllocated	ulong: bytes	0
failureUsed	ulong: bytes	0
failureWaste	ulong: bytes	0
gcId	uint	85
regionEndWaste	ulong: bytes	0
regionsRefilled	uint	0
undoWaste	ulong: bytes	0
used	ulong: bytes	0
wasted	ulong: bytes	0

allocated	ulong: bytes	25165824
directAllocated	ulong: bytes	0
failureUsed	ulong: bytes	0
failureWaste	ulong: bytes	0
gcId	uint	30
regionEndWaste	ulong: bytes	0
regionsRefilled	uint	12
undoWaste	ulong: bytes	0
used	ulong: bytes	25159368
wasted	ulong: bytes	6456

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 3

Old

Eden

Free

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

Normal

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

G1 Evacuation Pause

Allocation Failure

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

Before 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

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

Method

ConstMethod

ConstantPool

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	28049408
reserved	ulong: bytes	67108864
used	ulong: bytes	27921304

committed	ulong: bytes	31784960
reserved	ulong: bytes	1140850688
used	ulong: bytes	31468376

committed	ulong: bytes	3735552
reserved	ulong: bytes	1073741824
used	ulong: bytes	3547072

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

lo0

en0

utun5

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	34172043264
size	ulong: bytes	105906176
start	ulong: address	34066137088
used	ulong: bytes	105644208

end	ulong: address	34066137088
size	ulong: bytes	1137704960
start	ulong: address	32928432128
used	ulong: bytes	77345760

end	ulong: address	30407131136
size	ulong: bytes	342360064
start	ulong: address	30064771072
used	ulong: bytes	270464288

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	30072030784
description	string	null
referrer	Reference	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/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

address	ulong: address	30180806120
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	31611143120
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

Final reference

Soft reference

Weak 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 3

Empty Uncommitted

Empty Committed

Regular

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	0
lineNumber	int	181
method	Method
descriptor	string	(Ljava/util/Locale;)Ljava/text/DecimalFormatSymbols;
hidden	boolean	false
modifiers	int	25
name	string	getInstance
type	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
type	FrameType	Interpreted

bytecodeIndex	int	0
lineNumber	int	287
method	Method
descriptor	string	(Ljava/io/InputStream;Ljava/lang/String;)V
hidden	boolean	false
modifiers	int	2
name	string	read
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/jar/Manifest
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
type	FrameType	Interpreted

bytecodeIndex	int	10
lineNumber	int	156
method	Method
descriptor	string	(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/ArrayList
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	JIT compiled

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	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null

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

ICBufferFull

GenCollectForAllocation

ICBufferFull

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	31628197888
committedSize	ulong: bytes	1563426816
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	30918311936
committedSize	ulong: bytes	853540864
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 2

Large

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

Page Cache Hit L1

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

Uncommit

XML Content Types

address

Annotation: jdk.jfr.MemoryAddress

Examples 3

6564347904

4649009152

bits-per-second

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

Examples 3

3701800

16160

51736

bytes

Annotation: jdk.jfr.DataAmount(BYTES)

Examples 3

17029693440

73804944

17179869184

bytes-per-second

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

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

Examples 2

G1GC
G1GC

1.5955827870525086E9

8.340350789552855E8

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

33222.207

1000000000

microseconds

17+

Annotation: jdk.jfr.Timespan(MICROSECONDS)

millis

Annotation: jdk.jfr.Timespan(MILLISECONDS)

Examples 3

699156042

726092834

22148519000

nanos

Annotation: jdk.jfr.Timespan(NANOSECONDS)

Examples 3

-9223372036854775808

10000000

320000000

percentage

Annotation: jdk.jfr.Percentage

Examples 3

0.009866054

0.45

0.47368422

tickspan

Annotation: jdk.jfr.Timespan(TICKS)

Examples 3

77029796625

3593250

2163042

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

classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/jar/Manifest$FastInputStream
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

null

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	25
name	string	getInstance
type	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

descriptor	string	(Ljava/io/InputStream;Ljava/lang/String;)V
hidden	boolean	false
modifiers	int	2
name	string	read
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/jar/Manifest
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

descriptor	string	(Ljava/lang/String;)V
hidden	boolean	false
modifiers	int	2
name	string	putStringValue
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

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.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

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/util/jar

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/cldr

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/spi

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	0
lineNumber	int	287
method	Method
descriptor	string	(Ljava/io/InputStream;Ljava/lang/String;)V
hidden	boolean	false
modifiers	int	2
name	string	read
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/jar/Manifest
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
type	FrameType	Interpreted
		…
truncated	boolean	false

frames	StackFrame
bytecodeIndex	int	10
lineNumber	int	156
method	Method
descriptor	string	(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/ArrayList
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	JIT compiled
		…
truncated	boolean	false

frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	181
method	Method
descriptor	string	(Ljava/util/Locale;)Ljava/text/DecimalFormatSymbols;
hidden	boolean	false
modifiers	int	25
name	string	getInstance
type	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
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	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	scala-execution-context-global-58
javaThreadId	long	58
osName	string	scala-execution-context-global-58
osThreadId	long	38147
virtual	boolean	false

group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	UCT-akka.actor.default-dispatcher-14
javaThreadId	long	136
osName	string	UCT-akka.actor.default-dispatcher-14
osThreadId	long	35339
virtual	boolean	false

group	ThreadGroup
name	string	main
parent	ThreadGroup
name	string	system
parent	ThreadGroup	null
javaName	string	scala-execution-context-global-64
javaThreadId	long	64
osName	string	scala-execution-context-global-64
osThreadId	long	37379
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

87097460333

93744159333

970728584

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

true

false

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

2.0

-1.0

0.0

float


Parameter Type	float
Field Type	float
Java Type	float

Examples 3

2.5381775

2.5977247

1.6117458

int


Parameter Type	s4
Field Type	s4
Java Type	int

Examples 3

long


Parameter Type	s8
Field Type	s8
Java Type	long

Examples 3

35339

136

21922

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

java/util/jar/Manifest$FastInputStream

java/util/jar

bootstrap

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