Introduction

The following are the events for the OpenJDK 21 (jdk-21+15, 26-March-2023). 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.

Flight Recorder

DumpReason

default profiling startTime 11 17 20 21

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 20 21

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

Examples 3

amount	ulong: bytes	16356
startTime	long: millis	536626408042
total	ulong: bytes	588938

amount	ulong: bytes	660
startTime	long: millis	498194392834
total	ulong: bytes	660

amount	ulong: bytes	16356
startTime	long: millis	439990282750
total	ulong: bytes	1374244

Flush

experimental startTime duration 14 17 20 21

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	246
flushId	ulong	350
size	ulong: bytes	50227
startTime	long: millis	604282522167

elements	ulong	3598
flushId	ulong	172
size	ulong: bytes	1103588
startTime	long: millis	483336611084

elements	ulong	5752
flushId	ulong	214
size	ulong: bytes	959357
startTime	long: millis	487372360333

ActiveRecording

default profiling startTime duration stackTrace 11 17 20 21

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_UseParallelGC.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	1673458001344
stackTrace	StackTrace	null
startTime	long: millis	376195834

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	1673457379057
stackTrace	StackTrace	null
startTime	long: millis	333187834

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	1673458608832
stackTrace	StackTrace	null
startTime	long: millis	357238083

ActiveSetting

default profiling startTime duration stackTrace 11 17 20 21

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	45
name	string	enabled
stackTrace	StackTrace	null
startTime	long: millis	381379409250
value	string	true

id	long	1479
name	string	threshold
stackTrace	StackTrace	null
startTime	long: millis	483203615292
value	string	10 ms

id	long	89
name	string	enabled
stackTrace	StackTrace	null
startTime	long: millis	476715963750
value	string	true

JVM

JVMInformation

default profiling startTime duration end chunk 11 17 20 21

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	1673458608531
jvmVersion	string	OpenJDK 64-Bit Server VM (19+36-sapmachine) for bsd-aarch64 JRE (19+36-sapmachine), built on Sep 19 2022 15:20:37 by "apurple" with clang Apple LLVM 13.0.0 (clang-1300.0.29.3)
pid	long	60548
startTime	long: millis	443575897167

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	1673458001022
jvmVersion	string	OpenJDK 64-Bit Server VM (19+36-sapmachine) for bsd-aarch64 JRE (19+36-sapmachine), built on Sep 19 2022 15:20:37 by "apurple" with clang Apple LLVM 13.0.0 (clang-1300.0.29.3)
pid	long	59959
startTime	long: millis	508761828500

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	1673457378757
jvmVersion	string	OpenJDK 64-Bit Server VM (19+36-sapmachine) for bsd-aarch64 JRE (19+36-sapmachine), built on Sep 19 2022 15:20:37 by "apurple" with clang Apple LLVM 13.0.0 (clang-1300.0.29.3)
pid	long	59413
startTime	long: millis	619359387250

InitialSystemProperty

default profiling startTime duration end chunk 11 17 20 21

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.specification.name
startTime	long: millis	429022745708
value	string	Java Virtual Machine Specification

key	string	java.vm.compressedOopsMode
startTime	long: millis	508761861500
value	string	Zero based

key	string	java.home
startTime	long: millis	487872224542
value	string	[...]/.sdkman/candidates/java/19-sapmchn

JVM: Class Loading

ClassLoad

startTime duration eventThread stackTrace 11 17 20 21

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	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	19
name	string	java/net
initiatingClassLoader	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	19
name	string	java/net
loadedClass	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	19
name	string	java/net
hidden	boolean	true
modifiers	int	4144
name	string	org.apache.spark.storage.BlockManagerMasterEndpoint$$Lambda$18856+0x0000000804247080/1741599207
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	19
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	org/apache/spark/storage
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	(Ljava/lang/ClassLoader;Ljava/lang/Class;Ljava/lang/String;[BIILjava/security/ProtectionDomain;ZILjava/lang/Object;)Ljava/lang/Class;
hidden	boolean	false
modifiers	int	264
name	string	defineClass0
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	1057
name	string	java/lang/ClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	19
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	445005730375

definingClassLoader	ClassLoader	null
initiatingClassLoader	ClassLoader	null
loadedClass	Class
classLoader	ClassLoader	null
hidden	boolean	true
modifiers	int	48
name	string	java.lang.invoke.LambdaForm$MH+0x0000000800242000/1634717656
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	19
name	string	java/lang/invoke
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	(Ljava/lang/ClassLoader;Ljava/lang/Class;Ljava/lang/String;[BIILjava/security/ProtectionDomain;ZILjava/lang/Object;)Ljava/lang/Class;
hidden	boolean	false
modifiers	int	264
name	string	defineClass0
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	1057
name	string	java/lang/ClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	19
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	true
startTime	long: millis	484513587125

definingClassLoader	ClassLoader	null
initiatingClassLoader	ClassLoader	null
loadedClass	Class
classLoader	ClassLoader	null
hidden	boolean	true
modifiers	int	48
name	string	java.lang.invoke.LambdaForm$MH+0x00000008041f8400/2056910531
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	19
name	string	java/lang/invoke
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	-1
method	Method
descriptor	string	(Ljava/lang/ClassLoader;Ljava/lang/Class;Ljava/lang/String;[BIILjava/security/ProtectionDomain;ZILjava/lang/Object;)Ljava/lang/Class;
hidden	boolean	false
modifiers	int	264
name	string	defineClass0
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	1057
name	string	java/lang/ClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	19
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	true
startTime	long: millis	502792795959

ClassDefine

startTime eventThread stackTrace 11 17 20 21

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	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	19
name	string	java/net
hidden	boolean	false
modifiers	int	49
name	string	org/apache/spark/sql/Encoders$$typecreator1$11
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	19
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	org/apache/spark/sql
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	19
name	string	java/net
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	19
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	537859501459

definedClass	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	19
name	string	java/net
hidden	boolean	false
modifiers	int	49
name	string	org/apache/spark/sql/Encoders$$typecreator1$2
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	19
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	org/apache/spark/sql
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	19
name	string	java/net
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	19
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	450107186833

definedClass	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	19
name	string	java/net
hidden	boolean	false
modifiers	int	49
name	string	org/apache/spark/sql/SQLImplicits$$typecreator1$7
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	19
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	org/apache/spark/sql
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	19
name	string	java/net
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	19
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	553761918959

ClassRedefinition

default profiling startTime 15 17 20 21

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 20 21

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 20 21

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 20 21

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	19
name	string	java/net
startTime	long: millis	543927320917
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	19
name	string	java/net
hidden	boolean	false
modifiers	int	49
name	string	scala/reflect/ManifestFactory$BooleanManifest
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	19
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	scala/reflect

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	19
name	string	java/net
startTime	long: millis	559700777667
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	19
name	string	java/net
hidden	boolean	false
modifiers	int	49
name	string	scala/reflect/ManifestFactory$AnyManifest
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	19
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	scala/reflect

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	19
name	string	java/net
startTime	long: millis	458806026667
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	19
name	string	java/net
hidden	boolean	false
modifiers	int	49
name	string	scala/concurrent/stm/ccstm/InTxnImpl$
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	19
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	scala/concurrent/stm/ccstm

JVM: Code Cache

CodeCacheFull

default profiling startTime eventThread 11 17 20 21

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 20 21

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 'profiled nmethods'
entryCount	int	25390
fullCount	int	0
methodCount	int	25390
reservedTopAddress	ulong: address	5223170048
startAddress	ulong: address	5100273664
startTime	long: millis	470835542500
unallocatedCapacity	ulong: bytes	48915072

adaptorCount	int	0
codeBlobType	CodeBlobType	CodeHeap 'non-profiled nmethods'
entryCount	int	20281
fullCount	int	0
methodCount	int	20281
reservedTopAddress	ulong: address	5754585088
startAddress	ulong: address	5631672320
startTime	long: millis	558813426084
unallocatedCapacity	ulong: bytes	83355136

adaptorCount	int	1858
codeBlobType	CodeBlobType	CodeHeap 'non-nmethods'
entryCount	int	1946
fullCount	int	0
methodCount	int	0
reservedTopAddress	ulong: address	5238521856
startAddress	ulong: address	5232672768
startTime	long: millis	531351862542
unallocatedCapacity	ulong: bytes	3411712

CodeCacheConfiguration

default profiling startTime end chunk 11 17 20 21

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	5351931904
startAddress	ulong: address	5100273664
startTime	long: millis	381397790333

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	5754585088
startAddress	ulong: address	5502926848
startTime	long: millis	507460806000

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	5361434624
startAddress	ulong: address	5109776384
startTime	long: millis	585978467000

JVM: Compiler

JITRestart

default profiling startTime eventThread 17 20 21

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 20 21

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

Examples 3

codeSize	ulong: bytes	16400
compileId	int	59252
compileLevel	ushort	3
compiler	CompilerType	c1
inlinedBytes	ulong: bytes	696
isOsr	boolean	false
method	Method
descriptor	string	()Ljava/lang/Object;
hidden	boolean	false
modifiers	int	1
name	string	doUpdate
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	19
name	string	java/net
hidden	boolean	false
modifiers	int	33
name	string	org/apache/spark/status/LiveTask
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	19
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	org/apache/spark/status
startTime	long: millis	476403056250
succeded	boolean	true

codeSize	ulong: bytes	2584
compileId	int	60862
compileLevel	ushort	3
compiler	CompilerType	c1
inlinedBytes	ulong: bytes	44
isOsr	boolean	false
method	Method
descriptor	string	(Ljava/util/Queue;)Z
hidden	boolean	false
modifiers	int	20
name	string	runAllTasksFrom
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	19
name	string	java/net
hidden	boolean	false
modifiers	int	1057
name	string	io/netty/util/concurrent/SingleThreadEventExecutor
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	19
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	io/netty/util/concurrent
startTime	long: millis	450817346958
succeded	boolean	true

codeSize	ulong: bytes	61784
compileId	int	70436
compileLevel	ushort	2
compiler	CompilerType	c1
inlinedBytes	ulong: bytes	2026
isOsr	boolean	false
method	Method
descriptor	string	(Lorg/apache/xbean/asm9/MethodVisitor;Lorg/apache/xbean/asm9/Context;I)V
hidden	boolean	false
modifiers	int	2
name	string	readCode
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	19
name	string	java/net
hidden	boolean	false
modifiers	int	33
name	string	org/apache/xbean/asm9/ClassReader
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	19
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	org/apache/xbean/asm9
startTime	long: millis	576789166459
succeded	boolean	true

CompilerPhase

default profiling startTime duration eventThread 11 17 20 21

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 20 21

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	70552
failureMessage	string	concurrent class loading
startTime	long: millis	567868026750

compileId	int	70411
failureMessage	string	concurrent class loading
startTime	long: millis	576786520292

compileId	int	70375
failureMessage	string	concurrent class loading
startTime	long: millis	473461510833

CompilerInlining

startTime eventThread 11 17 20 21

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	13
callee	CalleeMethod
descriptor	string	()Z
name	string	cancellationRequested
type	string	java/util/stream/Sink
caller	Method
descriptor	string	()Z
hidden	boolean	false
modifiers	int	1
name	string	cancellationRequested
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/stream/SliceOps$2$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	19
name	string	java/util/stream
compileId	int	58956
message	string	inline (hot)
startTime	long: millis	483204344250
succeeded	boolean	true

bci	int	2
callee	CalleeMethod
descriptor	string	(Ljava/lang/Object;)Lscala/Option;
name	string	get
type	string	scala/collection/MapOps
caller	Method
descriptor	string	(Ljava/lang/Object;)Z
hidden	boolean	false
modifiers	int	1
name	string	contains
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	19
name	string	java/net
hidden	boolean	false
modifiers	int	1537
name	string	scala/collection/MapOps
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	19
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	scala/collection
compileId	int	59185
message	string	no static binding
startTime	long: millis	381397746792
succeeded	boolean	false

bci	int	1
callee	CalleeMethod
descriptor	string	()J
name	string	finishTime
type	string	org/apache/spark/scheduler/TaskInfo
caller	Method
descriptor	string	()Z
hidden	boolean	false
modifiers	int	1
name	string	finished
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	19
name	string	java/net
hidden	boolean	false
modifiers	int	33
name	string	org/apache/spark/scheduler/TaskInfo
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	19
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	org/apache/spark/scheduler
compileId	int	59252
message	string	inline
startTime	long: millis	476403129084
succeeded	boolean	true

Deoptimization

default profiling startTime eventThread stackTrace 14 17 20 21

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	reinterpret
bci	int	37
compileId	int	29506
compiler	CompilerType	c2
instruction	Bytecode	ifnonnull
lineNumber	int	1669
method	Method
descriptor	string	()I
hidden	boolean	false
modifiers	int	16
name	string	getFence
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/HashMap$HashMapSpliterator
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	19
name	string	java/util
reason	DeoptimizationReason	unstable_if
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	37
lineNumber	int	1669
method	Method
descriptor	string	()I
hidden	boolean	false
modifiers	int	16
name	string	getFence
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/HashMap$HashMapSpliterator
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	19
name	string	java/util
type	FrameType	JIT compiled
		…
truncated	boolean	false
startTime	long: millis	450718873042

action	DeoptimizationAction	reinterpret
bci	int	37
compileId	int	20277
compiler	CompilerType	c2
instruction	Bytecode	ifnonnull
lineNumber	int	1669
method	Method
descriptor	string	()I
hidden	boolean	false
modifiers	int	16
name	string	getFence
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/HashMap$HashMapSpliterator
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	19
name	string	java/util
reason	DeoptimizationReason	unstable_if
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	37
lineNumber	int	1669
method	Method
descriptor	string	()I
hidden	boolean	false
modifiers	int	16
name	string	getFence
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/HashMap$HashMapSpliterator
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	19
name	string	java/util
type	FrameType	JIT compiled
		…
truncated	boolean	false
startTime	long: millis	538300614500

action	DeoptimizationAction	reinterpret
bci	int	5
compileId	int	24613
compiler	CompilerType	c2
instruction	Bytecode	ifge
lineNumber	int	1026
method	Method
descriptor	string	(I)V
hidden	boolean	false
modifiers	int	17
name	string	acquireShared
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	1057
name	string	java/util/concurrent/locks/AbstractQueuedSynchronizer
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	19
name	string	java/util/concurrent/locks
reason	DeoptimizationReason	unstable_if
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	5
lineNumber	int	1026
method	Method
descriptor	string	(I)V
hidden	boolean	false
modifiers	int	17
name	string	acquireShared
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	1057
name	string	java/util/concurrent/locks/AbstractQueuedSynchronizer
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	19
name	string	java/util/concurrent/locks
type	FrameType	Inlined
		…
truncated	boolean	false
startTime	long: millis	560454086750

CompilerStatistics

default profiling startTime every chunk 11 17 20 21

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	10
compileCount	int	64582
invalidatedCount	int	0
nmethodCodeSize	ulong: bytes	79755264
nmethodsSize	ulong: bytes	127497176
osrBytesCompiled	ulong: bytes	0
osrCompileCount	int	680
peakTimeSpent	long: millis	20643
standardBytesCompiled	ulong: bytes	0
standardCompileCount	int	63902
startTime	long: millis	575561205667
totalTimeSpent	long: millis	755336

bailoutCount	int	12
compileCount	int	79416
invalidatedCount	int	0
nmethodCodeSize	ulong: bytes	110317952
nmethodsSize	ulong: bytes	173415280
osrBytesCompiled	ulong: bytes	0
osrCompileCount	int	733
peakTimeSpent	long: millis	19331
standardBytesCompiled	ulong: bytes	0
standardCompileCount	int	78683
startTime	long: millis	590150830584
totalTimeSpent	long: millis	479956

bailoutCount	int	14
compileCount	int	79619
invalidatedCount	int	0
nmethodCodeSize	ulong: bytes	104523904
nmethodsSize	ulong: bytes	168976184
osrBytesCompiled	ulong: bytes	0
osrCompileCount	int	759
peakTimeSpent	long: millis	9368
standardBytesCompiled	ulong: bytes	0
standardCompileCount	int	78860
startTime	long: millis	493877378917
totalTimeSpent	long: millis	540921

CompilerConfiguration

default profiling startTime end chunk 11 17 20 21

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

startTime	long: millis	476739505625
threadCount	int	4
tieredCompilation	boolean	true

startTime	long: millis	448145311625
threadCount	int	4
tieredCompilation	boolean	true

startTime	long: millis	483215015417
threadCount	int	4
tieredCompilation	boolean	true

JVM: Diagnostics

SyncOnValueBasedClass

experimental default profiling startTime eventThread stackTrace 16 17 20 21

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 20 21

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

JVM: Flag

IntFlagChanged

default profiling startTime 11 17 20 21

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 20 21

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 20 21

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 20 21

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 20 21

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 20 21

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 20 21

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 chunk 11 17 20 21

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	VerifyMetaspaceInterval
origin	FlagValueOrigin	Default
startTime	long: millis	588922524000
value	int	0

name	string	DeoptimizeObjectsALotThreadCountSingle
origin	FlagValueOrigin	Default
startTime	long: millis	476739510792
value	int	1

name	string	VerifyMetaspaceInterval
origin	FlagValueOrigin	Default
startTime	long: millis	431570198708
value	int	0

UnsignedIntFlag

default profiling startTime duration end chunk 11 17 20 21

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	StringDeduplicationAgeThreshold
origin	FlagValueOrigin	Default
startTime	long: millis	487898220167
value	uint	3

name	string	G1RemSetArrayOfCardsEntriesBase
origin	FlagValueOrigin	Default
startTime	long: millis	438636160542
value	uint	4

name	string	StringDeduplicationAgeThreshold
origin	FlagValueOrigin	Default
startTime	long: millis	552281875334
value	uint	3

LongFlag

default profiling startTime duration end chunk 11 17 20 21

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	MaxTrivialSize
origin	FlagValueOrigin	Default
startTime	long: millis	483215036750
value	long	6

name	string	MaxLoopPad
origin	FlagValueOrigin	Default
startTime	long: millis	476739516417
value	long	15

name	string	Tier2BackEdgeThreshold
origin	FlagValueOrigin	Default
startTime	long: millis	381397836833
value	long	0

UnsignedLongFlag

default profiling startTime duration end chunk 11 17 20 21

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	MaxVirtMemFraction
origin	FlagValueOrigin	Default
startTime	long: millis	476739537084
value	ulong	2

name	string	NUMASpaceResizeRate
origin	FlagValueOrigin	Default
startTime	long: millis	483215060125
value	ulong	1073741824

name	string	TLABWasteIncrement
origin	FlagValueOrigin	Default
startTime	long: millis	381398002792
value	ulong	4

DoubleFlag

default profiling startTime duration end chunk 11 17 20 21

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	InitialRAMPercentage
origin	FlagValueOrigin	Default
startTime	long: millis	416003485500
value	double	1.5625

name	string	ZFragmentationLimit
origin	FlagValueOrigin	Default
startTime	long: millis	489885068084
value	double	25.0

name	string	ZFragmentationLimit
origin	FlagValueOrigin	Default
startTime	long: millis	507460857959
value	double	25.0

BooleanFlag

default profiling startTime duration end chunk 11 17 20 21

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	NeverActAsServerClassMachine
origin	FlagValueOrigin	Default
startTime	long: millis	483215105167
value	boolean	false

name	string	UseCompressedOops
origin	FlagValueOrigin	Ergonomic
startTime	long: millis	381398021375
value	boolean	true

name	string	ClassUnloading
origin	FlagValueOrigin	Default
startTime	long: millis	476739571917
value	boolean	true

StringFlag

default profiling startTime duration end chunk 11 17 20 21

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	StartFlightRecording
origin	FlagValueOrigin	Command line
startTime	long: millis	381398121583
value	string	filename=[...]/code/experiments/jfreventcollector/jfr/sample_UseSerialGC.jfr,settings=[...]/code/experiments/jfreventcollector/.cache/jfc.jfc

name	string	HeapDumpPath
origin	FlagValueOrigin	Default
startTime	long: millis	489885161000
value	string	null

name	string	OnOutOfMemoryError
origin	FlagValueOrigin	Default
startTime	long: millis	487898302459
value	string

JVM: GC: Collector

GarbageCollection

default profiling startTime duration 11 17 20 21

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	Heap Inspection Initiated GC
gcId	uint	762
longestPause	Tickspan	418481833
name	GCName	SerialOld
startTime	long: millis	458697831625
sumOfPauses	Tickspan	418481833

cause	GCCause	Heap Inspection Initiated GC
gcId	uint	797
longestPause	Tickspan	272291542
name	GCName	G1Full
startTime	long: millis	524785456000
sumOfPauses	Tickspan	272291542

cause	GCCause	Heap Inspection Initiated GC
gcId	uint	534
longestPause	Tickspan	175663708
name	GCName	ParallelOld
startTime	long: millis	575188826334
sumOfPauses	Tickspan	175663708

SystemGC

default profiling startTime duration eventThread stackTrace 17 20 21

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	19
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	554602703375

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	19
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	455492918583

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	19
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	591579970834

ParallelOldGarbageCollection

default profiling startTime duration 11 17 20 21

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	30065295360
gcId	uint	564
startTime	long: millis	595020895167

YoungGarbageCollection

default profiling startTime duration 11 17 20 21

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	850
startTime	long: millis	556219961375
tenuringThreshold	uint	15

gcId	uint	744
startTime	long: millis	452888334375
tenuringThreshold	uint	15

gcId	uint	479
startTime	long: millis	532346110125
tenuringThreshold	uint	15

OldGarbageCollection

default profiling startTime duration 11 17 20 21

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	498
startTime	long: millis	552284174750

gcId	uint	788
startTime	long: millis	473466134458

gcId	uint	786
startTime	long: millis	505643414709

G1GarbageCollection

default profiling startTime duration 11 17 20 21

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	763
startTime	long: millis	476716162709
type	G1YCType	Concurrent Start

JVM: GC: Configuration

GCConfiguration

default profiling startTime duration end chunk 11 17 20 21

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	549472041209
usesDynamicGCThreads	boolean	true
youngCollector	GCName	ParallelScavenge

concurrentGCThreads	uint	2
gcTimeRatio	uint	12
isExplicitGCConcurrent	boolean	false
isExplicitGCDisabled	boolean	false
oldCollector	GCName	G1Old
parallelGCThreads	uint	8
pauseTarget	long: millis	-9223372036854775808
startTime	long: millis	593476997834
usesDynamicGCThreads	boolean	true
youngCollector	GCName	G1New

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	459121629667
usesDynamicGCThreads	boolean	true
youngCollector	GCName	DefNew

GCSurvivorConfiguration

default profiling startTime duration end chunk 11 17 20 21

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	522032611792

initialTenuringThreshold	ubyte	7
maxTenuringThreshold	ubyte	15
startTime	long: millis	563210583667

initialTenuringThreshold	ubyte	7
maxTenuringThreshold	ubyte	15
startTime	long: millis	431885220917

GCTLABConfiguration

default profiling startTime duration end chunk 11 17 20 21

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	542144224250
tlabRefillWasteLimit	ulong: bytes	64
usesTLABs	boolean	true

minTLABSize	ulong: bytes	2048
startTime	long: millis	429367067875
tlabRefillWasteLimit	ulong: bytes	64
usesTLABs	boolean	true

minTLABSize	ulong: bytes	2048
startTime	long: millis	563210584584
tlabRefillWasteLimit	ulong: bytes	64
usesTLABs	boolean	true

GCHeapConfiguration

default profiling startTime duration end chunk 11 17 20 21

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	531606419167
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	482414441959
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	439103795125
usesCompressedOops	boolean	true

YoungGenerationConfiguration

default profiling startTime duration end chunk 11 17 20 21

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	443917122667

maxSize	ulong: bytes	1431306240
minSize	ulong: bytes	89128960
newRatio	uint	2
startTime	long: millis	490099315542

maxSize	ulong: bytes	2575302656
minSize	ulong: bytes	1363144
newRatio	uint	2
startTime	long: millis	495019018584

JVM: GC: Detailed

ZThreadDebug

internal startTime duration eventThread 18 20 21

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 20 21

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	808
gcTime	long: millis	74
pauseTarget	long: millis	200
startTime	long: millis	538971487584
timeSlice	long: millis	201

EvacuationInformation

default profiling startTime 11 17 20 21

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	3
allocationRegionsUsedAfter	ulong: bytes	4176400
allocationRegionsUsedBefore	ulong: bytes	947712
bytesCopied	ulong: bytes	3228688
cSetRegions	uint	402
cSetUsedAfter	ulong: bytes	0
cSetUsedBefore	ulong: bytes	842120568
gcId	uint	852
regionsFreed	uint	402
startTime	long: millis	556676865417

ObjectCountAfterGC

startTime 11 17 20 21

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	75364
gcId	uint	468
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	19
name	string	java/lang
startTime	long: millis	503217812084
totalSize	ulong: bytes	8771672

count	long	48371
gcId	uint	765
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	19
name	string	java/lang/invoke
startTime	long: millis	476816729417
totalSize	ulong: bytes	2321808

count	long	57169
gcId	uint	713
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/lang/reflect/Method
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	19
name	string	java/lang/reflect
startTime	long: millis	406435462625
totalSize	ulong: bytes	5030872

G1EvacuationYoungStatistics

default profiling startTime 11 17 20 21

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	497151436084
statistics	G1EvacuationStatistics
allocated	ulong: bytes	2036360
directAllocated	ulong: bytes	159288
failureUsed	ulong: bytes	0
failureWaste	ulong: bytes	0
gcId	uint	780
regionEndWaste	ulong: bytes	0
regionsRefilled	uint	2
undoWaste	ulong: bytes	0
used	ulong: bytes	1909552
wasted	ulong: bytes	3968

G1EvacuationOldStatistics

default profiling startTime 11 17 20 21

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	574766049792
statistics	G1EvacuationStatistics
allocated	ulong: bytes	20640
directAllocated	ulong: bytes	272
failureUsed	ulong: bytes	0
failureWaste	ulong: bytes	0
gcId	uint	878
regionEndWaste	ulong: bytes	0
regionsRefilled	uint	1
undoWaste	ulong: bytes	0
used	ulong: bytes	15072
wasted	ulong: bytes	264

G1BasicIHOP

default profiling startTime 11 17 20 21

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	141797008
gcId	uint	835
lastMarkingDuration	long: millis	266
recentAllocationRate	double: bytes-per-second	24259.183898413823
recentMutatorAllocationSize	ulong: bytes	6192
recentMutatorDuration	long: millis	255
startTime	long: millis	545411446417
targetOccupancy	ulong: bytes	497025024
threshold	ulong: bytes	79174622
thresholdPercentage	float: percentage	0.15929705

G1AdaptiveIHOP

default profiling startTime 11 17 20 21

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	1231028224
currentOccupancy	ulong: bytes	209854320
gcId	uint	790
ihopTargetOccupancy	ulong: bytes	1950456217
predictedAllocationRate	double: bytes-per-second	4.728535042093943E8
predictedMarkingDuration	long: millis	1757
predictionActive	boolean	true
startTime	long: millis	509487367917
threshold	ulong: bytes	0
thresholdPercentage	float: percentage	0.0

PromoteObjectInNewPLAB

profiling startTime eventThread 11 17 20 21

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

ParallelGC
G1GC

gcId	uint	457
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	0
name	string	[F
package	Package	null
objectSize	ulong: bytes	56
plabSize	ulong: bytes	32752
startTime	long: millis	483216593417
tenured	boolean	false
tenuringAge	uint	0

gcId	uint	763
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	0
name	string	[F
package	Package	null
objectSize	ulong: bytes	56
plabSize	ulong: bytes	21904
startTime	long: millis	476717633417
tenured	boolean	false
tenuringAge	uint	0

PromoteObjectOutsidePLAB

profiling startTime eventThread 11 17 20 21

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

ParallelGC
G1GC

gcId	uint	459
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	19
name	string	java/net
hidden	boolean	false
modifiers	int	0
name	string	[Lorg/apache/spark/unsafe/memory/MemoryBlock;
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	19
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	org/apache/spark/unsafe/memory
objectSize	ulong: bytes	32784
startTime	long: millis	485541229584
tenured	boolean	false
tenuringAge	uint	0

gcId	uint	776
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	19
name	string	java/net
hidden	boolean	false
modifiers	int	0
name	string	[Lorg/apache/spark/unsafe/memory/MemoryBlock;
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	19
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	org/apache/spark/unsafe/memory
objectSize	ulong: bytes	32784
startTime	long: millis	490275106459
tenured	boolean	false
tenuringAge	uint	0

PromotionFailed

default profiling startTime 11 17 20 21

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 20 21

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 20 21

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Concurrent Mode failed

Configuration	enabled
default	true
profiling	true

Field	Type	Description
gcId	uint	GC Identifier

Examples 1

G1GC

gcId	uint	764
startTime	long: millis	476879007250

GCCPUTime

default profiling startTime 20 21

Category: Java Virtual Machine / GC / Detailed

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

AllocationRequiringGC

startTime eventThread stackTrace 11 17 20 21

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	760
size	ulong: bytes	112
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	7
lineNumber	int	394
method	Method
descriptor	string	(Lscala/concurrent/stm/TxnExecutor;Lscala/Function1;)Ljava/lang/Object;
hidden	boolean	false
modifiers	int	2
name	string	topLevelAtomicImpl
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	19
name	string	java/net
hidden	boolean	false
modifiers	int	33
name	string	scala/concurrent/stm/ccstm/InTxnImpl
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	19
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	scala/concurrent/stm/ccstm
type	FrameType	Inlined
		…
truncated	boolean	false
startTime	long: millis	457664029792

gcId	uint	524
size	ulong: bytes	56
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	52
lineNumber	int	239
method	Method
descriptor	string	(I)[Ljava/lang/Object;
hidden	boolean	false
modifiers	int	2
name	string	grow
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.b