Introduction

The following are the events for the OpenJDK 23 (jdk-23+36, 15-August-2024), and Graal VM 24.1.0 (jdk-23+28) . 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	37
flushId	ulong	73
size	ulong: bytes	52611
startTime	long: millis	80386772167

elements	ulong	4716
flushId	ulong	73
size	ulong: bytes	814010
startTime	long: millis	76612094125

elements	ulong	3532
flushId	ulong	45
size	ulong: bytes	1147779
startTime	long: millis	46796291875

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.
disk	boolean 21+	To Disk
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_UseParallelGC.jfr
disk	boolean	true
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	1702899886817
stackTrace	StackTrace	null
startTime	long: millis	93731899458

destination	string	[...]/code/experiments/jfreventcollector/jfr/sample_UseG1GC.jfr
disk	boolean	true
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	1702902685041
stackTrace	StackTrace	null
startTime	long: millis	669832834

destination	string	[...]/code/experiments/jfreventcollector/jfr/sample_UseSerialGC.jfr
disk	boolean	true
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	75960656375

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	22
name	string	threshold
stackTrace	StackTrace	null
startTime	long: millis	669832834
value	string	0 ms

id	long	15
name	string	enabled
stackTrace	StackTrace	null
startTime	long: millis	360834042
value	string	true

id	long	49
name	string	threshold
stackTrace	StackTrace	null
startTime	long: millis	416785542
value	string	0 ms

JVM

JVMInformation

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

Category: Java Virtual Machine

Description of JVM and the Java application

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

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

Examples 3

javaArguments	string	[...]/code/experiments/jfreventcollector/.cache/renaissance.jar -t 5 -r 1 all
jvmArguments	string	-XX:StartFlightRecording=filename=[...]/code/experiments/jfreventcollector/jfr/sample_UseParallelGC.jfr,settings=[...]/code/experiments/jfreventcollector/.cache/jfc.jfc -XX:+UseParallelGC
jvmFlags	string	null
jvmName	string	OpenJDK 64-Bit Server VM
jvmStartTime	long: epochmillis	1702899886436
jvmVersion	string	OpenJDK 64-Bit Server VM (21.0.1+12-LTS) for bsd-aarch64 JRE (21.0.1+12-LTS), built on 2023-10-17T00:00:00Z by "admin" with clang Apple LLVM 12.0.0 (clang-1200.0.32.29)
pid	long	13981
startTime	long: millis	39218543667

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	96709433583

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	36095816500

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	jdk.debug
startTime	long: millis	30585953875
value	string	release

key	string	java.vm.info
startTime	long: millis	40019893875
value	string	mixed mode

key	string	java.vm.vendor
startTime	long: millis	672946334
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	app
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	jdk/internal/loader/ClassLoaders$AppClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	jdk/internal/loader
loadedClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	1537
name	string	java/lang/CharSequence
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	(Z)[Ljava/lang/reflect/Method;
hidden	boolean	false
modifiers	int	258
name	string	getDeclaredMethods0
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/lang/Class
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	390356417

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	1537
name	string	sun/util/logging/PlatformLogger$ConfigurableBridge
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	sun/util/logging
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	10
lineNumber	int	66
method	Method
descriptor	string	()V
hidden	boolean	false
modifiers	int	1
name	string	<init>
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/logging/SimpleFormatter
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.logging
name	string	java.logging
version	string	21.0.1
name	string	java/util/logging
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	453802333

definingClassLoader	ClassLoader
name	string	bootstrap
type	Class	null
initiatingClassLoader	ClassLoader
name	string	app
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	jdk/internal/loader/ClassLoaders$AppClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	jdk/internal/loader
loadedClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/lang/IllegalArgumentException
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	2
lineNumber	int	21
method	Method
descriptor	string	()V
hidden	boolean	false
modifiers	int	8
name	string	<clinit>
type	Class
classLoader	ClassLoader
name	string	app
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	jdk/internal/loader/ClassLoaders$AppClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	jdk/internal/loader
hidden	boolean	false
modifiers	int	49
name	string	org/renaissance/core/Launcher
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	app
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	jdk/internal/loader/ClassLoaders$AppClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	jdk/internal/loader
location	string	null
name	string	null
version	string	null
name	string	org/renaissance/core
type	FrameType	Interpreted
truncated	boolean	false
startTime	long: millis	715474584

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/locale/provider/JRELocaleProviderAdapter
package	Package
exported	boolean	true
module	Module
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/locale/provider
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	466508417

definedClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	1537
name	string	sun/nio/ByteBuffered
package	Package
exported	boolean	false
module	Module
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
definingClassLoader	ClassLoader
name	string	bootstrap
type	Class	null
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	6
lineNumber	int	164
method	Method
descriptor	string	()Ljava/nio/ByteBuffer;
hidden	boolean	false
modifiers	int	1
name	string	getByteBuffer
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	1057
name	string	jdk/internal/loader/Resource
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	jdk/internal/loader
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	385800625

definedClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	48
name	string	java/util/regex/Pattern$Branch
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/regex
definingClassLoader	ClassLoader
name	string	bootstrap
type	Class	null
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	812
lineNumber	int	3259
method	Method
descriptor	string	()Ljava/util/regex/Pattern$Node;
hidden	boolean	false
modifiers	int	2
name	string	group0
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/util/regex/Pattern
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/regex
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	721963625

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	3889500458
unloadedClass	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	false
modifiers	int	1537
name	string	org/sparkproject/guava/collect/Multiset
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	org/sparkproject/guava/collect

definingClassLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
startTime	long: millis	4558700083
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	49
name	string	scala/collection/immutable/SetBuilderImpl
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	scala/collection/immutable

definingClassLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
startTime	long: millis	5994069459
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	49
name	string	org/slf4j/LoggerFactory
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/slf4j

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	2940
fullCount	int	0
methodCount	int	2940
reservedTopAddress	ulong: address	4733009920
startAddress	ulong: address	4610097152
startTime	long: millis	39597077917
unallocatedCapacity	ulong: bytes	117689984

adaptorCount	int	0
codeBlobType	CodeBlobType	CodeHeap 'non-profiled nmethods'
entryCount	int	4086
fullCount	int	0
methodCount	int	4086
reservedTopAddress	ulong: address	5217714176
startAddress	ulong: address	5094801408
startTime	long: millis	93549329292
unallocatedCapacity	ulong: bytes	114295168

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

CodeCacheConfiguration

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

Category: Java Virtual Machine / Code Cache

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

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

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

Examples 3

expansionSize	ulong: bytes	65536
initialSize	ulong: bytes	2555904
minBlockLength	ulong: bytes	6
nonNMethodSize	ulong: bytes	5839564
nonProfiledSize	ulong: bytes	122909338
profiledSize	ulong: bytes	122909338
reservedSize	ulong: bytes	251658240
reservedTopAddress	ulong: address	4771921920
startAddress	ulong: address	4520263680
startTime	long: millis	27602497542

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	75962738417

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	423298667

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	ulong: 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	int	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
arenaBytes	ulong: bytes 23+	Arena Usage

Examples 3

codeSize	ulong: bytes	7464
compileId	int	6094
compileLevel	ushort	4
compiler	CompilerType	c2
inlinedBytes	ulong: bytes	1976
isOsr	boolean	false
method	Method
descriptor	string	(Lscala/collection/Iterator;Lakka/util/WildcardTree;)Lakka/util/WildcardTree;
hidden	boolean	false
modifiers	int	1
name	string	findWithTerminalDoubleWildcard
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	akka/util/WildcardTree
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/util
startTime	long: millis	14290207875
succeded	boolean	true

codeSize	ulong: bytes	38848
compileId	int	14618
compileLevel	ushort	4
compiler	CompilerType	c2
inlinedBytes	ulong: bytes	6581
isOsr	boolean	false
method	Method
descriptor	string	(Lio/netty/channel/ChannelHandlerContext;ILio/netty/handler/codec/http2/Http2Headers;IZZISZLio/netty/channel/ChannelPromise;)Lio/netty/channel/ChannelFuture;
hidden	boolean	false
modifiers	int	2
name	string	writeHeadersInternal
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	io/netty/handler/codec/http2/DefaultHttp2FrameWriter
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
startTime	long: millis	32553846667
succeded	boolean	true

codeSize	ulong: bytes	4896
compileId	int	14428
compileLevel	ushort	4
compiler	CompilerType	c2
inlinedBytes	ulong: bytes	644
isOsr	boolean	false
method	Method
descriptor	string	(Lcom/twitter/util/Try;)V
hidden	boolean	false
modifiers	int	1
name	string	apply
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	com/twitter/util/Promise$Monitored
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	com/twitter/util
startTime	long: millis	41520275708
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	int	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	int	Compilation Identifier

Examples 3

compileId	int	3706
failureMessage	string	concurrent class loading
startTime	long: millis	3613493750

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

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

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	int	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	1
callee	CalleeMethod
descriptor	string	(D)J
name	string	doubleToRawLongBits
type	string	java/lang/Double
caller	Method
descriptor	string	(D)I
hidden	boolean	false
modifiers	int	9
name	string	getExponent
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/lang/Math
package	Package
exported	boolean	true
module	Module
classLoader	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	int	1454
message	string	intrinsic
startTime	long: millis	668077292
succeeded	boolean	true

bci	int	16
callee	CalleeMethod
descriptor	string	([BII)[B
name	string	copyOfRange
type	string	java/util/Arrays
caller	Method
descriptor	string	([BII)Ljava/lang/String;
hidden	boolean	false
modifiers	int	9
name	string	newString
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	48
name	string	java/lang/StringLatin1
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/lang
compileId	int	1448
message	string	inline
startTime	long: millis	415453208
succeeded	boolean	true

bci	int	30
callee	CalleeMethod
descriptor	string	()Ljava/lang/String;
name	string	toString
type	string	java/lang/StringBuilder
caller	Method
descriptor	string	(II)V
hidden	boolean	false
modifiers	int	10
name	string	checkLength
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	int	1413
message	string	inline
startTime	long: millis	359620333
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	int	Compilation Identifier
compiler	CompilerType	Compiler Consider contributing a description to jfreventcollector.
method	Method	Method Consider contributing a description to jfreventcollector.
lineNumber	int	Line Number
bci	int	Bytecode Index
instruction	Bytecode	Instruction Consider contributing a description to jfreventcollector.
reason	DeoptimizationReason	Reason Consider contributing a description to jfreventcollector.
action	DeoptimizationAction	Action Consider contributing a description to jfreventcollector.

Examples 3

action	DeoptimizationAction	maybe_recompile
bci	int	12
compileId	int	2639
compiler	CompilerType	c2
instruction	Bytecode	invokeinterface
lineNumber	int	197
method	Method
descriptor	string	(Ljava/lang/Object;)V
hidden	boolean	false
modifiers	int	1
name	string	accept
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/stream/ReferencePipeline$3$1
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/stream
reason	DeoptimizationReason	class_check
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	12
lineNumber	int	197
method	Method
descriptor	string	(Ljava/lang/Object;)V
hidden	boolean	false
modifiers	int	1
name	string	accept
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/stream/ReferencePipeline$3$1
package	Package
exported	boolean	true
module	Module
classLoader	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	1505609542

action	DeoptimizationAction	reinterpret
bci	int	12
compileId	int	2658
compiler	CompilerType	c2
instruction	Bytecode	lookupswitch
lineNumber	int	2296
method	Method
descriptor	string	(Ljava/util/regex/Pattern$Node;)Ljava/util/regex/Pattern$Node;
hidden	boolean	false
modifiers	int	2
name	string	sequence
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/util/regex/Pattern
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/regex
reason	DeoptimizationReason	unstable_if
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	12
lineNumber	int	2296
method	Method
descriptor	string	(Ljava/util/regex/Pattern$Node;)Ljava/util/regex/Pattern$Node;
hidden	boolean	false
modifiers	int	2
name	string	sequence
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/util/regex/Pattern
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/regex
type	FrameType	JIT compiled
		…
truncated	boolean	false
startTime	long: millis	5680886625

action	DeoptimizationAction	maybe_recompile
bci	int	12
compileId	int	3089
compiler	CompilerType	c2
instruction	Bytecode	invokeinterface
lineNumber	int	185
method	Method
descriptor	string	()I
hidden	boolean	false
modifiers	int	1
name	string	getOpFlags
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/stream/ReduceOps$3
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/util/stream
reason	DeoptimizationReason	class_check
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	12
lineNumber	int	185
method	Method
descriptor	string	()I
hidden	boolean	false
modifiers	int	1
name	string	getOpFlags
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/stream/ReduceOps$3
package	Package
exported	boolean	true
module	Module
classLoader	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	3541730708

CompilerQueueUtilization

default profiling startTime duration every chunk 22 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	10 s
profiling	true	5 s

Field	Type	Description
compiler	CompilerType	Compiler Consider contributing a description to jfreventcollector.
addedRate	long: hertz	Requets Added Rate Requests added per second
removedRate	long: hertz	Requests Removed Rate Requests removed per second
queueSize	long	Queue Size
peakQueueSize	long	Peak Queue Size
addedCount	long	Requests Added
removedCount	long	Requests Removed
totalAddedCount	long	Total Requests Added
totalRemovedCount	long	Total Requests Removed
compilerThreadCount	int	Compiler Thread Count

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	5
compileCount	int	33660
invalidatedCount	int	0
nmethodCodeSize	ulong: bytes	49059080
nmethodsSize	ulong: bytes	73029568
osrBytesCompiled	ulong: bytes	0
osrCompileCount	int	233
peakTimeSpent	long: millis	1103
standardBytesCompiled	ulong: bytes	0
standardCompileCount	int	33427
startTime	long: millis	66190551500
totalTimeSpent	long: millis	81812

bailoutCount	int	3
compileCount	int	18044
invalidatedCount	int	0
nmethodCodeSize	ulong: bytes	21894448
nmethodsSize	ulong: bytes	34168928
osrBytesCompiled	ulong: bytes	0
osrCompileCount	int	178
peakTimeSpent	long: millis	953
standardBytesCompiled	ulong: bytes	0
standardCompileCount	int	17866
startTime	long: millis	63488086542
totalTimeSpent	long: millis	45242

bailoutCount	int	3
compileCount	int	33971
invalidatedCount	int	0
nmethodCodeSize	ulong: bytes	43494168
nmethodsSize	ulong: bytes	66889776
osrBytesCompiled	ulong: bytes	0
osrCompileCount	int	230
peakTimeSpent	long: millis	1360
standardBytesCompiled	ulong: bytes	0
standardCompileCount	int	33741
startTime	long: millis	94426111208
totalTimeSpent	long: millis	80412

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
dynamicCompilerThreadCount	boolean 20+	Uses Dynamic Number of Compiler Threads

Examples 3

dynamicCompilerThreadCount	boolean	true
startTime	long: millis	30586816333
threadCount	int	4
tieredCompilation	boolean	true

dynamicCompilerThreadCount	boolean	true
startTime	long: millis	22150016917
threadCount	int	4
tieredCompilation	boolean	true

dynamicCompilerThreadCount	boolean	true
startTime	long: millis	30519906375
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

Information about a successfully written Java heap dump

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

Field	Type	Description
destination	string	Destination Path of the Dump
size	long	Size
gcBeforeDump	boolean	GC Before Dump
onOutOfMemoryError	boolean	Heap Dump on Out of Memory Error
overwrite	boolean 21+	Overwrite Heap dump overwrites previous file location if it exists
compression	int 21+	Compression Level Compression level of the dump, if larger than 0 we use gzip compression with this level

JavaAgent

default profiling startTime end of every chunk 21 23 24

Category: Java Virtual Machine / Diagnostics

A Java programming language agent making use of the java.lang.instrument package for instrumenting programs running on the JVM

Configuration	enabled	period
default	true	endChunk
profiling	true	endChunk

Field	Type	Description
name	string	Name
options	string	Options
dynamic	boolean	Dynamic If the agent attached to the JVM dynamically during runtime, i.e. not at startup
initializationTime	Ticks	Initialization Time The time the JVM initialized the agent
initializationDuration	Tickspan	Initialization Duration The duration of executing the initialization method, either premain or agentmain

NativeAgent

default profiling startTime end of every chunk 21 23 24

Category: Java Virtual Machine / Diagnostics

A native programming language agent making use of the JVMTI interface used by development, profiling and monitoring tools

Configuration	enabled	period
default	true	endChunk
profiling	true	endChunk

Field	Type	Description
name	string	Name
options	string	Options
dynamic	boolean	Dynamic If the library attached to the JVM dynamically during runtime, i.e. not at startup
initializationTime	Ticks	Initialization Time The time the JVM initialized the agent
initializationDuration	Tickspan	Initialization Duration The duration of executing the JVMTI VMInit event callback. If no VMInit callback is specified, the duration is 0. For a dynamically loaded agent, it is the duration of executing the call to Agent_OnAttach.
path	string	Path The path of the library

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	ThreadPriorityPolicy
origin	FlagValueOrigin	Default
startTime	long: millis	15845307542
value	int	0

name	string	JavaPriority1_To_OSPriority
origin	FlagValueOrigin	Default
startTime	long: millis	39268374542
value	int	-1

name	string	SoftwarePrefetchHintDistance
origin	FlagValueOrigin	Default
startTime	long: millis	12863166084
value	int	384

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	G1ConcRefinementThreads
origin	FlagValueOrigin	Default
startTime	long: millis	30586826000
value	uint	0

name	string	ConcGCThreads
origin	FlagValueOrigin	Ergonomic
startTime	long: millis	36097512334
value	uint	2

name	string	TestCrashInErrorHandler
origin	FlagValueOrigin	Default
startTime	long: millis	84416231583
value	uint	0

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	Tier0InvokeNotifyFreqLog
origin	FlagValueOrigin	Default
startTime	long: millis	364810333
value	long	7

name	string	MaxJumpTableSize
origin	FlagValueOrigin	Default
startTime	long: millis	676080959
value	long	65000

name	string	NestedInliningSizeRatio
origin	FlagValueOrigin	Default
startTime	long: millis	423468292
value	long	90

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	ReservedCodeCacheSize
origin	FlagValueOrigin	Ergonomic
startTime	long: millis	364821000
value	ulong	251658240

name	string	StringTableSize
origin	FlagValueOrigin	Default
startTime	long: millis	676109667
value	ulong	65536

name	string	NonProfiledCodeHeapSize
origin	FlagValueOrigin	Ergonomic
startTime	long: millis	423577708
value	ulong	122909338

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	ZAllocationSpikeTolerance
origin	FlagValueOrigin	Default
startTime	long: millis	75962783667
value	double	2.0

name	string	ZAllocationSpikeTolerance
origin	FlagValueOrigin	Default
startTime	long: millis	17899885000
value	double	2.0

name	string	MinRAMPercentage
origin	FlagValueOrigin	Default
startTime	long: millis	36097544209
value	double	50.0

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	PrintIR2
origin	FlagValueOrigin	Default
startTime	long: millis	676151875
value	boolean	false

name	string	GenerateArrayStoreCheck
origin	FlagValueOrigin	Default
startTime	long: millis	364841833
value	boolean	true

name	string	UseSlowPath
origin	FlagValueOrigin	Default
startTime	long: millis	423599792
value	boolean	false

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	SharedClassListFile
origin	FlagValueOrigin	Default
startTime	long: millis	12863353209
value	string	null

name	string	SharedArchiveConfigFile
origin	FlagValueOrigin	Default
startTime	long: millis	30586896875
value	string	null

name	string	CompileCommand
origin	FlagValueOrigin	Default
startTime	long: millis	40031305000
value	string

JVM: GC: Collector

GarbageCollection

default profiling startTime duration eventThread 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	G1 Evacuation Pause
gcId	uint	64
longestPause	Tickspan	1058833
name	GCName	G1New
startTime	long: millis	22055115292
sumOfPauses	Tickspan	1058833

cause	GCCause	Heap Inspection Initiated GC
gcId	uint	93
longestPause	Tickspan	573922750
name	GCName	SerialOld
startTime	long: millis	15033490292
sumOfPauses	Tickspan	573922750

cause	GCCause	Allocation Failure
gcId	uint	67
longestPause	Tickspan	942750
name	GCName	ParallelScavenge
startTime	long: millis	49340687958
sumOfPauses	Tickspan	942750

SystemGC

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

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	45628555917

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	31427419583

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	73672167917

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	30147084288
gcId	uint	54
startTime	long: millis	30481085167

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	98
startTime	long: millis	69782739542
tenuringThreshold	uint	15

gcId	uint	37
startTime	long: millis	9303276792
tenuringThreshold	uint	15

gcId	uint	58
startTime	long: millis	5911704958
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	3
startTime	long: millis	970101667

gcId	uint	393
startTime	long: millis	88128329583

gcId	uint	29
startTime	long: millis	7881811750

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	58
startTime	long: millis	21579569000
type	G1YCType	Normal

ZYoungGarbageCollection

default profiling startTime duration eventThread 21 23 24

Category: Java Virtual Machine / GC / Collector

Extra information specific to ZGC 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

ZOldGarbageCollection

default profiling startTime duration eventThread 21 23 24

Category: Java Virtual Machine / GC / Collector

Extra information specific to ZGC Old Garbage Collections

Configuration	enabled	threshold
default	true	0 ms
profiling	true	0 ms

Field	Type	Description
gcId	uint	GC Identifier

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	39413196458
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	96681275042
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	78213061250
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	40220267458

initialTenuringThreshold	ubyte	7
maxTenuringThreshold	ubyte	15
startTime	long: millis	30586923375

initialTenuringThreshold	ubyte	7
maxTenuringThreshold	ubyte	15
startTime	long: millis	36156161250

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	436497958
tlabRefillWasteLimit	ulong: bytes	64
usesTLABs	boolean	true

minTLABSize	ulong: bytes	2048
startTime	long: millis	76136302208
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	75222450667
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	63145624459
usesCompressedOops	boolean	true

YoungGenerationConfiguration

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

Category: Java Virtual Machine / GC / Configuration

The configuration of the young generation of the garbage collected heap

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

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

Examples 3

maxSize	ulong: bytes	1431633920
minSize	ulong: bytes	89456640
newRatio	uint	2
startTime	long: millis	76136304042

maxSize	ulong: bytes	1431306240
minSize	ulong: bytes	89128960
newRatio	uint	2
startTime	long: millis	79064868458

maxSize	ulong: bytes	2575302656
minSize	ulong: bytes	1363144
newRatio	uint	2
startTime	long: millis	36156165792

JVM: GC: Detailed

ZThreadDebug

internal startTime duration eventThread 18 21 23 24

Category: Java Virtual Machine / GC / Detailed

Temporary latency measurements used during development and debugging of ZGC

Only valid for the ZGC.

Field	Type	Description
gcId	uint	GC Identifier
name	string	Name The name of the GC runner

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	89
gcTime	long: millis	2
pauseTarget	long: millis	200
startTime	long: millis	31191847459
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	2
allocationRegionsUsedAfter	ulong: bytes	4109984
allocationRegionsUsedBefore	ulong: bytes	0
bytesCopied	ulong: bytes	4109984
cSetRegions	uint	182
cSetUsedAfter	ulong: bytes	0
cSetUsedBefore	ulong: bytes	379684744
gcId	uint	58
regionsFreed	uint	182
startTime	long: millis	21580801417

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	93366
gcId	uint	69
objectClass	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	false
modifiers	int	33
name	string	akka/dispatch/AbstractNodeQueue$Node
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	8663866792
totalSize	ulong: bytes	2240784

count	long	214370
gcId	uint	28
objectClass	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	false
modifiers	int	33
name	string	akka/actor/TypedCreatorFunctionConsumer
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	17449627375
totalSize	ulong: bytes	5144880

count	long	758
gcId	uint	1
objectClass	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
startTime	long: millis	684981625
totalSize	ulong: bytes	36384

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	1879329917
statistics	G1EvacuationStatistics
allocated	ulong: bytes	6770816
directAllocated	ulong: bytes	786464
failureUsed	ulong: bytes	0
failureWaste	ulong: bytes	0
gcId	uint	14
numDirectAllocated	ulong	5
numPlabsFilled	ulong	4374877392
regionEndWaste	ulong: bytes	0
regionsRefilled	uint	4
undoWaste	ulong: bytes	0
used	ulong: bytes	6299872
wasted	ulong: bytes	496

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	9321041375
statistics	G1EvacuationStatistics
allocated	ulong: bytes	12582912
directAllocated	ulong: bytes	0
failureUsed	ulong: bytes	0
failureWaste	ulong: bytes	0
gcId	uint	37
numDirectAllocated	ulong	6147041496
numPlabsFilled	ulong	0
regionEndWaste	ulong: bytes	0
regionsRefilled	uint	6
undoWaste	ulong: bytes	0
used	ulong: bytes	9537032
wasted	ulong: bytes	31424

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	98498504
gcId	uint	95
lastMarkingDuration	long: millis	880
recentAllocationRate	double: bytes-per-second	0.0
recentMutatorAllocationSize	ulong: bytes	0
recentMutatorDuration	long: millis	387
startTime	long: millis	33496150500
targetOccupancy	ulong: bytes	413138944
threshold	ulong: bytes	185912524
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	912261120
currentOccupancy	ulong: bytes	605115040
gcId	uint	42
ihopTargetOccupancy	ulong: bytes	1659581235
predictedAllocationRate	double: bytes-per-second	3.0753563072438364E9
predictedMarkingDuration	long: millis	338
predictionActive	boolean	false
startTime	long: millis	12094101500
threshold	ulong: bytes	786117427
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 Scavenge, 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 scavenge 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

G1GC
ParallelGC

gcId	uint	3
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
objectSize	ulong: bytes	24
plabSize	ulong: bytes	6016
startTime	long: millis	940094125
tenured	boolean	true
tenuringAge	uint	1

gcId	uint	5
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
objectSize	ulong: bytes	24
plabSize	ulong: bytes	8176
startTime	long: millis	1163406792
tenured	boolean	true
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 Scavenge, 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 scavenge the object survives. Newly allocated objects have tenuring age 0.
tenured	boolean	Tenured True if object was promoted to Old space, otherwise the object was aged and copied to a Survivor space

Examples 2

G1GC
ParallelGC

gcId	uint	59
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	12544
startTime	long: millis	21659679750
tenured	boolean	false
tenuringAge	uint	0

gcId	uint	13
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	39976
startTime	long: millis	2084178083
tenured	boolean	false
tenuringAge	uint	0

PromotionFailed

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Promotion of an object failed

Configuration	enabled
default	true
profiling	true

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

EvacuationFailed

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Evacuation of an object failed

Configuration	enabled
default	true
profiling	true

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

ConcurrentModeFailure

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Concurrent Mode failed

Configuration	enabled
default	true
profiling	true

Field	Type	Description
gcId	uint	GC Identifier

GCCPUTime

default profiling startTime 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

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

Configuration	enabled
default	true
profiling	true

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

Examples 3

gcId	uint	94
realTime	ulong: nanos	19999980
startTime	long: millis	67843895000
systemTime	ulong: nanos	19999999
userTime	ulong: nanos	9999999

gcId	uint	20
realTime	ulong: nanos	9999990
startTime	long: millis	2611069834
systemTime	ulong: nanos	20000000
userTime	ulong: nanos	40000000

gcId	uint	30
realTime	ulong: nanos	9999990
startTime	long: millis	1964790958
systemTime	ulong: nanos	0
userTime	ulong: nanos	0

AllocationRequiringGC

startTime eventThread stackTrace 11 17 21 23 24 graal vm

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	31
size	ulong: bytes	64
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	217
method	Method
descriptor	string	(Lakka/actor/ActorRef;Lakka/actor/ActorRef;IIIZ)Ledu/rice/habanero/benchmarks/uct/UctAkkaActorBenchmark$NodeActor;
hidden	boolean	false
modifiers	int	4121
name	string	$anonfun$createNodeActor$1
type	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
hidden	boolean	false
modifiers	int	33
name	string	edu/rice/habanero/benchmarks/uct/UctAkkaActorBenchmark$NodeActor$
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21.0.1
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	edu/rice/habanero/benchmarks/uct
type	FrameType	Inlined
		…
truncated	boolean	false
startTime	long: millis	18794748875

gcId	uint	34
size	ulong: bytes	17448
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	7
lineNumber	int	3513
method	Method
descriptor	string	([Ljava/lang/Object;ILjava/lang/Class;)[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	JIT compiled
		…
truncated	boolean	false
startTime	long: millis	2009693708

gcId	uint	63
size	ulong: bytes	1976
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	4
lineNumber	int	220
method	Method
descriptor	string	()[I
hidden	boolean	false
modifiers	int	2
name	string	findNearestCentroid
type	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	<