Introduction

The following are the events for the OpenJDK 14 (jdk-14.0.2+12, 25-September-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 21 22

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 22

Category: Flight Recorder

Appearing in: ShenandoahGC

Missing in: G1GC, ParallelGC, SerialGC, ZGC

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 1

ShenandoahGC

amount	ulong: bytes	16356
startTime	long: millis	822209750708
total	ulong: bytes	1734196

Flush

experimental startTime duration 14 17 21 22

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	167
flushId	ulong	32
size	ulong: bytes	88141
startTime	long: millis	37401217916

elements	ulong	2587
flushId	ulong	37
size	ulong: bytes	603086
startTime	long: millis	45589321416

elements	ulong	1145
flushId	ulong	31
size	ulong: bytes	687080
startTime	long: millis	34980446291

ActiveRecording

default profiling startTime duration stackTrace 11 17 21 22

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

Category: Flight Recorder

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

Configuration	enabled
default	true
profiling	true

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

Examples 3

destination	string	[...]/code/experiments/jfreventcollector/jfr/sample_UseSerialGC.jfr
flushInterval	long: millis	1000
id	long	1
maxAge	long: millis	9223372036854775807
maxSize	long: bytes	262144000
name	string	1
recordingDuration	long: millis	9223372036854775807
recordingStart	long: epochmillis	1695641333965
stackTrace	StackTrace	null
startTime	long: millis	47002991666

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	1695641190609
stackTrace	StackTrace	null
startTime	long: millis	44970506583

destination	string	[...]/code/experiments/jfreventcollector/jfr/sample_UseG1GC.jfr
flushInterval	long: millis	1000
id	long	1
maxAge	long: millis	9223372036854775807
maxSize	long: bytes	0
name	string	1
recordingDuration	long: millis	9223372036854775807
recordingStart	long: epochmillis	1695641083678
stackTrace	StackTrace	null
startTime	long: millis	398288666

ActiveSetting

default profiling startTime duration stackTrace 11 17 21 22

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	8
name	string	enabled
stackTrace	StackTrace	null
startTime	long: millis	313165708
value	string	true

id	long	36
name	string	period
stackTrace	StackTrace	null
startTime	long: millis	398288666
value	string	everyChunk

id	long	42
name	string	enabled
stackTrace	StackTrace	null
startTime	long: millis	318884958
value	string	true

JVM

JVMInformation

default profiling startTime duration end chunk 11 17 21 22

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	1695641333687
jvmVersion	string	OpenJDK 64-Bit Server VM (21-ea+26-2328) for bsd-aarch64 JRE (21-ea+26-2328), built on 2023-06-08T17:38:39Z by "mach5one" with clang Apple LLVM 12.0.0 (clang-1200.0.32.29)
pid	long	26371
startTime	long: millis	111338191208

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	1695641083299
jvmVersion	string	OpenJDK 64-Bit Server VM (21-ea+26-2328) for bsd-aarch64 JRE (21-ea+26-2328), built on 2023-06-08T17:38:39Z by "mach5one" with clang Apple LLVM 12.0.0 (clang-1200.0.32.29)
pid	long	25717
startTime	long: millis	87227021125

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	1695641190320
jvmVersion	string	OpenJDK 64-Bit Server VM (21-ea+26-2328) for bsd-aarch64 JRE (21-ea+26-2328), built on 2023-06-08T17:38:39Z by "mach5one" with clang Apple LLVM 12.0.0 (clang-1200.0.32.29)
pid	long	26042
startTime	long: millis	320600791

InitialSystemProperty

default profiling startTime duration end chunk 11 17 21 22

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.version
startTime	long: millis	78890532333
value	string	21-ea+26-2328

key	string	java.vm.specification.name
startTime	long: millis	72280479416
value	string	Java Virtual Machine Specification

key	string	java.library.path
startTime	long: millis	56373483041
value	string	[...]/Library/Java/Extensions:/Library/Java/Extensions:/Network/Library/Java/Extensions:/System/Library/Java/Extensions:/usr/lib/java:.

JVM: Class Loading

ClassLoad

startTime duration eventThread stackTrace 11 17 21 22

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	null
initiatingClassLoader	ClassLoader	null
loadedClass	Class
classLoader	ClassLoader	null
hidden	boolean	true
modifiers	int	48
name	string	java.lang.invoke.LambdaForm$DMH+0x0000000801006800/831236296
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21-ea
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	21-ea
name	string	java/lang
type	FrameType	Native
		…
truncated	boolean	false
startTime	long: millis	409266125

definingClassLoader	ClassLoader
name	string	bootstrap
type	Class	null
initiatingClassLoader	ClassLoader
name	string	bootstrap
type	Class	null
loadedClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/Collections$SynchronizedCollection
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21-ea
name	string	java/util
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	2407
method	Method
descriptor	string	(Ljava/util/Set;Ljava/lang/Object;)Ljava/util/Set;
hidden	boolean	false
modifiers	int	8
name	string	synchronizedSet
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/Collections
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21-ea
name	string	java/util
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	331979750

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	49
name	string	sun/launcher/LauncherHelper
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-ea
name	string	sun/launcher
stackTrace	StackTrace	null
startTime	long: millis	331863666

ClassDefine

startTime eventThread stackTrace 11 17 21 22

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	49
name	string	sun/util/locale/InternalLocaleBuilder
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-ea
name	string	sun/util/locale
definingClassLoader	ClassLoader
name	string	bootstrap
type	Class	null
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	6
lineNumber	int	1872
method	Method
descriptor	string	(Ljava/lang/String;)Ljava/util/Locale;
hidden	boolean	false
modifiers	int	9
name	string	forLanguageTag
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/util/Locale
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21-ea
name	string	java/util
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	342770375

definedClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	16433
name	string	sun/util/logging/PlatformLogger$Level
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21-ea
name	string	sun/util/logging
definingClassLoader	ClassLoader
name	string	bootstrap
type	Class	null
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	28
lineNumber	int	500
method	Method
descriptor	string	()V
hidden	boolean	false
modifiers	int	8
name	string	<clinit>
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	sun/util/logging/PlatformLogger
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21-ea
name	string	sun/util/logging
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	414174458

definedClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	1537
name	string	java/lang/System$Logger
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21-ea
name	string	java/lang
definingClassLoader	ClassLoader
name	string	bootstrap
type	Class	null
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	10
lineNumber	int	66
method	Method
descriptor	string	()V
hidden	boolean	false
modifiers	int	1
name	string	<init>
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/logging/SimpleFormatter
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.logging
name	string	java.logging
version	string	21-ea
name	string	java/util/logging
type	FrameType	Interpreted
		…
truncated	boolean	false
startTime	long: millis	337237916

ClassUnload

startTime eventThread 11 17 21 22

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-ea
name	string	java/net
startTime	long: millis	4278727458
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-ea
name	string	java/net
hidden	boolean	false
modifiers	int	33
name	string	org/slf4j/impl/Log4jLoggerFactory
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-ea
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	org/slf4j/impl

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-ea
name	string	java/net
startTime	long: millis	7149326333
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-ea
name	string	java/net
hidden	boolean	false
modifiers	int	48
name	string	org/sparkproject/guava/collect/ImmutableMapValues
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-ea
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-ea
name	string	java/net
startTime	long: millis	4256983583
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-ea
name	string	java/net
hidden	boolean	false
modifiers	int	1537
name	string	scala/collection/convert/AsJavaExtensions
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-ea
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	scala/collection/convert

JVM: Code Cache

CodeCacheFull

default profiling startTime eventThread 11 17 21 22

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
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

CodeCacheStatistics

default profiling startTime every chunk 11 17 21 22

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	644
codeBlobType	CodeBlobType	CodeHeap 'non-nmethods'
entryCount	int	735
fullCount	int	0
methodCount	int	0
reservedTopAddress	ulong: address	5500747776
startAddress	ulong: address	5494898688
startTime	long: millis	109232252958
unallocatedCapacity	ulong: bytes	4375168

adaptorCount	int	0
codeBlobType	CodeBlobType	CodeHeap 'profiled nmethods'
entryCount	int	5030
fullCount	int	0
methodCount	int	5030
reservedTopAddress	ulong: address	5240995840
startAddress	ulong: address	5118099456
startTime	long: millis	105762304708
unallocatedCapacity	ulong: bytes	108791040

adaptorCount	int	0
codeBlobType	CodeBlobType	CodeHeap 'profiled nmethods'
entryCount	int	1013
fullCount	int	0
methodCount	int	1013
reservedTopAddress	ulong: address	5491605504
startAddress	ulong: address	5368709120
startTime	long: millis	315640125
unallocatedCapacity	ulong: bytes	120200064

CodeCacheConfiguration

default profiling startTime end chunk 11 17 21 22

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	5620367360
startAddress	ulong: address	5368709120
startTime	long: millis	36813493583

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	5369757696
startAddress	ulong: address	5118099456
startTime	long: millis	41236001541

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	5623660544
startAddress	ulong: address	5372002304
startTime	long: millis	78919233041

JVM: Code Sweeper

SweepCodeCache

default profiling startTime duration eventThread 11 17 until JDK 20

Category: Java Virtual Machine / Code Sweeper

Appearing in: ShenandoahGC

Missing in: G1GC, ParallelGC, SerialGC, ZGC

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

Configuration	enabled	threshold
default	true	100 ms
profiling	true	100 ms

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

Examples 1

ShenandoahGC

flushedCount	uint	132
startTime	long: millis	907051477042
sweepId	int	120
sweptCount	uint	56809
zombifiedCount	uint	24

CodeSweeperStatistics

default profiling startTime every chunk 11 17 until JDK 20

Category: Java Virtual Machine / Code Sweeper

Appearing in: ShenandoahGC

Missing in: G1GC, ParallelGC, SerialGC, ZGC

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

Configuration	enabled	period
default	true	everyChunk
profiling	true	everyChunk

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

Examples 1

ShenandoahGC

methodReclaimedCount	int	18188
peakFractionTime	Tickspan	193465625
peakSweepTime	Tickspan	193465625
startTime	long: millis	803826094792
sweepCount	int	79
totalSweepTime	Tickspan	3304234670

CodeSweeperConfiguration

default profiling startTime end chunk 11 17 until JDK 20

Category: Java Virtual Machine / Code Sweeper

Appearing in: ShenandoahGC

Missing in: G1GC, ParallelGC, SerialGC, ZGC

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

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
sweeperEnabled	boolean	Code Sweeper Enabled
flushingEnabled	boolean	Code Cache Flushing Enabled

Examples 1

ShenandoahGC

flushingEnabled	boolean	true
startTime	long: millis	872559723250
sweeperEnabled	boolean	true

JVM: Compiler

Compilation

default profiling startTime duration eventThread 11 17 21 22

Category: Java Virtual Machine / Compiler

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

Configuration	enabled	threshold
default	true	1000 ms
profiling	true	100 ms

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

Examples 3

codeSize	ulong: bytes	44760
compileId	uint	9610
compileLevel	ushort	4
compiler	CompilerType	c2
inlinedBytes	ulong: bytes	7531
isOsr	boolean	false
method	Method
descriptor	string	()V
hidden	boolean	false
modifiers	int	0
name	string	fastPath
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-ea
name	string	java/net
hidden	boolean	false
modifiers	int	48
name	string	rx/internal/operators/OnSubscribeFromIterable$IterableProducer
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-ea
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	rx/internal/operators
startTime	long: millis	44909769125
succeded	boolean	true

codeSize	ulong: bytes	5864
compileId	uint	14896
compileLevel	ushort	4
compiler	CompilerType	c2
inlinedBytes	ulong: bytes	771
isOsr	boolean	false
method	Method
descriptor	string	(Lio/netty/channel/RecvByteBufAllocator$Handle;Z)V
hidden	boolean	false
modifiers	int	0
name	string	notifyReadComplete
type	Class
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21-ea
name	string	java/net
hidden	boolean	false
modifiers	int	48
name	string	io/netty/handler/codec/http2/AbstractHttp2StreamChannel$Http2ChannelUnsafe
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-ea
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	io/netty/handler/codec/http2
startTime	long: millis	49720573333
succeded	boolean	true

codeSize	ulong: bytes	15192
compileId	uint	15778
compileLevel	ushort	4
compiler	CompilerType	c2
inlinedBytes	ulong: bytes	2500
isOsr	boolean	false
method	Method
descriptor	string	(Lio/netty/channel/ChannelHandlerContext;Ljava/lang/Object;)V
hidden	boolean	false
modifiers	int	1
name	string	channelRead
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-ea
name	string	java/net
hidden	boolean	false
modifiers	int	1057
name	string	io/netty/handler/codec/ByteToMessageDecoder
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-ea
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	io/netty/handler/codec
startTime	long: millis	73265102625
succeded	boolean	true

CompilerPhase

default profiling startTime duration eventThread 11 17 21 22

Category: Java Virtual Machine / Compiler

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

Configuration	enabled	threshold
default	true	60 s
profiling	true	10 s

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

CompilationFailure

profiling startTime eventThread 11 17 21 22

Category: Java Virtual Machine / Compiler

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

Configuration	enabled
default	false
profiling	true

Field	Type	Description
failureMessage	string	Failure Message
compileId	uint	Compilation Identifier

Examples 3

compileId	uint	23269
failureMessage	string	concurrent class loading
startTime	long: millis	121205170500

compileId	uint	25728
failureMessage	string	concurrent class loading
startTime	long: millis	82942791208

compileId	uint	5038
failureMessage	string	concurrent class loading
startTime	long: millis	6426908583

CompilerInlining

startTime eventThread 11 17 21 22

Category: Java Virtual Machine / Compiler / Optimization

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

Examples 3

bci	int	264
callee	CalleeMethod
descriptor	string	(B)V
name	string	putUncheckedByte
type	string	jdk/jfr/internal/event/EventWriter
caller	Method
descriptor	string	(J)V
hidden	boolean	false
modifiers	int	2
name	string	putUncheckedLong
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	jdk/jfr/internal/event/EventWriter
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/jdk.jfr
name	string	jdk.jfr
version	string	21-ea
name	string	jdk/jfr/internal/event
compileId	uint	1509
message	string	callee uses too much stack
startTime	long: millis	399008291
succeeded	boolean	false

bci	int	162
callee	CalleeMethod
descriptor	string	(B)V
name	string	putUncheckedByte
type	string	jdk/jfr/internal/event/EventWriter
caller	Method
descriptor	string	(J)V
hidden	boolean	false
modifiers	int	2
name	string	putUncheckedLong
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	jdk/jfr/internal/event/EventWriter
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/jdk.jfr
name	string	jdk.jfr
version	string	21-ea
name	string	jdk/jfr/internal/event
compileId	uint	1485
message	string	callee uses too much stack
startTime	long: millis	319345875
succeeded	boolean	false

bci	int	116
callee	CalleeMethod
descriptor	string	(B)V
name	string	putUncheckedByte
type	string	jdk/jfr/internal/event/EventWriter
caller	Method
descriptor	string	(J)V
hidden	boolean	false
modifiers	int	2
name	string	putUncheckedLong
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	jdk/jfr/internal/event/EventWriter
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/jdk.jfr
name	string	jdk.jfr
version	string	21-ea
name	string	jdk/jfr/internal/event
compileId	uint	1463
message	string	callee uses too much stack
startTime	long: millis	314014833
succeeded	boolean	false

Deoptimization

default profiling startTime eventThread stackTrace 14 17 21 22

Category: Java Virtual Machine / Compiler

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

Configuration	enabled	stackTrace
default	true	false
profiling	true	true

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

Examples 3

action	DeoptimizationAction	maybe_recompile
bci	int	26
compileId	uint	2549
compiler	CompilerType	c2
instruction	Bytecode	invokeinterface
lineNumber	int	4502
method	Method
descriptor	string	(Ljava/util/regex/Matcher;ILjava/lang/CharSequence;)Z
hidden	boolean	false
modifiers	int	0
name	string	match
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	48
name	string	java/util/regex/Pattern$BmpCharPropertyGreedy
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21-ea
name	string	java/util/regex
reason	DeoptimizationReason	bimorphic_or_optimized_type_check
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	26
lineNumber	int	4502
method	Method
descriptor	string	(Ljava/util/regex/Matcher;ILjava/lang/CharSequence;)Z
hidden	boolean	false
modifiers	int	0
name	string	match
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	48
name	string	java/util/regex/Pattern$BmpCharPropertyGreedy
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21-ea
name	string	java/util/regex
type	FrameType	JIT compiled
		…
truncated	boolean	false
startTime	long: millis	1225079500

action	DeoptimizationAction	maybe_recompile
bci	int	242
compileId	uint	2134
compiler	CompilerType	c2
instruction	Bytecode	invokevirtual
lineNumber	int	1039
method	Method
descriptor	string	(Ljava/lang/Object;Ljava/lang/Object;Z)Ljava/lang/Object;
hidden	boolean	false
modifiers	int	16
name	string	putVal
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/concurrent/ConcurrentHashMap
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21-ea
name	string	java/util/concurrent
reason	DeoptimizationReason	class_check
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	242
lineNumber	int	1039
method	Method
descriptor	string	(Ljava/lang/Object;Ljava/lang/Object;Z)Ljava/lang/Object;
hidden	boolean	false
modifiers	int	16
name	string	putVal
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/concurrent/ConcurrentHashMap
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21-ea
name	string	java/util/concurrent
type	FrameType	JIT compiled
		…
truncated	boolean	false
startTime	long: millis	1299200958

action	DeoptimizationAction	maybe_recompile
bci	int	5
compileId	uint	3207
compiler	CompilerType	c2
instruction	Bytecode	invokeinterface
lineNumber	int	164
method	Method
descriptor	string	(J)V
hidden	boolean	false
modifiers	int	1
name	string	begin
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/stream/ReduceOps$3ReducingSink
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21-ea
name	string	java/util/stream
reason	DeoptimizationReason	bimorphic_or_optimized_type_check
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	5
lineNumber	int	164
method	Method
descriptor	string	(J)V
hidden	boolean	false
modifiers	int	1
name	string	begin
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/stream/ReduceOps$3ReducingSink
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21-ea
name	string	java/util/stream
type	FrameType	JIT compiled
		…
truncated	boolean	false
startTime	long: millis	6804944583

CompilerStatistics

default profiling startTime every chunk 11 17 21 22

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	12899
invalidatedCount	int	0
nmethodCodeSize	ulong: bytes	15506808
nmethodsSize	ulong: bytes	23780080
osrBytesCompiled	ulong: bytes	0
osrCompileCount	int	104
peakTimeSpent	long: millis	1185
standardBytesCompiled	ulong: bytes	0
standardCompileCount	int	12795
startTime	long: millis	47526246458
totalTimeSpent	long: millis	28636

bailoutCount	int	7
compileCount	int	33788
invalidatedCount	int	0
nmethodCodeSize	ulong: bytes	45166952
nmethodsSize	ulong: bytes	68530752
osrBytesCompiled	ulong: bytes	0
osrCompileCount	int	226
peakTimeSpent	long: millis	1607
standardBytesCompiled	ulong: bytes	0
standardCompileCount	int	33562
startTime	long: millis	109981241750
totalTimeSpent	long: millis	73650

bailoutCount	int	4
compileCount	int	17325
invalidatedCount	int	0
nmethodCodeSize	ulong: bytes	20838816
nmethodsSize	ulong: bytes	32194672
osrBytesCompiled	ulong: bytes	0
osrCompileCount	int	122
peakTimeSpent	long: millis	990
standardBytesCompiled	ulong: bytes	0
standardCompileCount	int	17203
startTime	long: millis	57476875166
totalTimeSpent	long: millis	50204

CompilerConfiguration

default profiling startTime end chunk 11 17 21 22

Category: Java Virtual Machine / Compiler

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

Configuration	enabled	period
default	true	beginChunk
profiling	true	beginChunk

Field	Type	Description
threadCount	int	Thread Count
tieredCompilation	boolean	Tiered Compilation

Examples 3

startTime	long: millis	45145924166
threadCount	int	4
tieredCompilation	boolean	true

startTime	long: millis	87234396625
threadCount	int	4
tieredCompilation	boolean	true

startTime	long: millis	111340662791
threadCount	int	4
tieredCompilation	boolean	true

JVM: Flag

IntFlagChanged

default profiling startTime 11 17 21 22

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 22

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 22

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 22

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 22

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 22

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 22

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 21 22

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	PerfMaxStringConstLength
origin	FlagValueOrigin	Default
startTime	long: millis	36813497875
value	int	1024

name	string	JavaPriority3_To_OSPriority
origin	FlagValueOrigin	Default
startTime	long: millis	45145935875
value	int	-1

name	string	PerfMaxStringConstLength
origin	FlagValueOrigin	Default
startTime	long: millis	41236005166
value	int	1024

UnsignedIntFlag

default profiling startTime duration end chunk 11 17 21 22

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	122971592041
value	uint	3

name	string	VerifyIterativeGVN
origin	FlagValueOrigin	Default
startTime	long: millis	52748840875
value	uint	0

name	string	GCCardSizeInBytes
origin	FlagValueOrigin	Default
startTime	long: millis	80787589041
value	uint	512

LongFlag

default profiling startTime duration end chunk 11 17 21 22

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	Tier2InvokeNotifyFreqLog
origin	FlagValueOrigin	Default
startTime	long: millis	320865250
value	long	11

name	string	ValueMapMaxLoopSize
origin	FlagValueOrigin	Default
startTime	long: millis	315655416
value	long	8

name	string	CICrashAt
origin	FlagValueOrigin	Default
startTime	long: millis	399763291
value	long	-1

UnsignedLongFlag

default profiling startTime duration end chunk 11 17 21 22

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	G1ReservePercent
origin	FlagValueOrigin	Default
startTime	long: millis	399775166
value	ulong	10

name	string	MinHeapFreeRatio
origin	FlagValueOrigin	Default
startTime	long: millis	315673791
value	ulong	40

name	string	NUMAInterleaveGranularity
origin	FlagValueOrigin	Default
startTime	long: millis	320884125
value	ulong	2097152

DoubleFlag

default profiling startTime duration end chunk 11 17 21 22

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	SelfDestructTimer
origin	FlagValueOrigin	Default
startTime	long: millis	47005897875
value	double	0.0

name	string	SelfDestructTimer
origin	FlagValueOrigin	Default
startTime	long: millis	122971622708
value	double	0.0

name	string	EscapeAnalysisTimeout
origin	FlagValueOrigin	Default
startTime	long: millis	52748873500
value	double	20.0

BooleanFlag

default profiling startTime duration end chunk 11 17 21 22

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	C1Breakpoint
origin	FlagValueOrigin	Default
startTime	long: millis	315694875
value	boolean	false

name	string	ImplicitDiv0Checks
origin	FlagValueOrigin	Default
startTime	long: millis	399793375
value	boolean	true

name	string	PrintLIR
origin	FlagValueOrigin	Default
startTime	long: millis	320897708
value	boolean	false

StringFlag

default profiling startTime duration end chunk 11 17 21 22

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	21672130291
value	string	null

name	string	DumpLoadedClassList
origin	FlagValueOrigin	Default
startTime	long: millis	18053338625
value	string	null

name	string	ExtraSharedClassListFile
origin	FlagValueOrigin	Default
startTime	long: millis	399828083
value	string	null

JVM: GC: Collector

GarbageCollection

default profiling startTime duration 11 17 21 22

Category: Java Virtual Machine / GC / Collector

Garbage collection performed by the JVM

Configuration	enabled	threshold
default	true	0 ms
profiling	true	0 ms

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

Examples 3

cause	GCCause	Allocation Failure
gcId	uint	44
longestPause	Tickspan	1380209
name	GCName	ParallelScavenge
startTime	long: millis	33969102166
sumOfPauses	Tickspan	1380209

cause	GCCause	Allocation Failure
gcId	uint	18
longestPause	Tickspan	5242458
name	GCName	DefNew
startTime	long: millis	1616277458
sumOfPauses	Tickspan	5242458

cause	GCCause	G1 Evacuation Pause
gcId	uint	7
longestPause	Tickspan	1863584
name	GCName	G1New
startTime	long: millis	1029838666
sumOfPauses	Tickspan	1863584

ParallelOldGarbageCollection

default profiling startTime duration 11 17 21 22

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	35
startTime	long: millis	25756926375

YoungGarbageCollection

default profiling startTime duration 11 17 21 22

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	5
startTime	long: millis	1012885833
tenuringThreshold	uint	1

gcId	uint	110
startTime	long: millis	48610802125
tenuringThreshold	uint	15

gcId	uint	69
startTime	long: millis	85278129958
tenuringThreshold	uint	15

OldGarbageCollection

default profiling startTime duration 11 17 21 22

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	35
startTime	long: millis	25756926375

gcId	uint	338
startTime	long: millis	87786156083

gcId	uint	196
startTime	long: millis	81066232916

G1GarbageCollection

default profiling startTime duration 11 17 21 22

Category: Java Virtual Machine / GC / Collector

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Extra information specific to G1 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	63
startTime	long: millis	25195078583
type	G1YCType	Normal

JVM: GC: Configuration

GCConfiguration

default profiling startTime duration end chunk 11 17 21 22

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	142138623750
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	81255077416
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	72233587208
usesDynamicGCThreads	boolean	true
youngCollector	GCName	G1New

GCSurvivorConfiguration

default profiling startTime duration end chunk 11 17 21 22

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	52842759333

initialTenuringThreshold	ubyte	7
maxTenuringThreshold	ubyte	15
startTime	long: millis	123099316166

initialTenuringThreshold	ubyte	7
maxTenuringThreshold	ubyte	15
startTime	long: millis	36813599500

GCTLABConfiguration

default profiling startTime duration end chunk 11 17 21 22

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	56630881458
tlabRefillWasteLimit	ulong: bytes	64
usesTLABs	boolean	true

minTLABSize	ulong: bytes	2048
startTime	long: millis	330696416
tlabRefillWasteLimit	ulong: bytes	64
usesTLABs	boolean	true

minTLABSize	ulong: bytes	2048
startTime	long: millis	100355684416
tlabRefillWasteLimit	ulong: bytes	64
usesTLABs	boolean	true

GCHeapConfiguration

default profiling startTime duration end chunk 11 17 21 22

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	22498712000
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	36813600541
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	406880916
usesCompressedOops	boolean	true

YoungGenerationConfiguration

default profiling startTime duration end chunk 11 17 21 22

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	1431306240
minSize	ulong: bytes	89128960
newRatio	uint	2
startTime	long: millis	109610423125

maxSize	ulong: bytes	1431633920
minSize	ulong: bytes	89456640
newRatio	uint	2
startTime	long: millis	111536189875

maxSize	ulong: bytes	2575302656
minSize	ulong: bytes	1363144
newRatio	uint	2
startTime	long: millis	33749560541

JVM: GC: Detailed

G1MMU

default profiling startTime 11 17 21 22

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	64
gcTime	long: millis	96
pauseTarget	long: millis	200
startTime	long: millis	25675740041
timeSlice	long: millis	201

EvacuationInformation

default profiling startTime 11 17 21 22

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	8
allocationRegionsUsedAfter	ulong: bytes	16777216
allocationRegionsUsedBefore	ulong: bytes	0
bytesCopied	ulong: bytes	16777216
cSetRegions	uint	29
cSetUsedAfter	ulong: bytes	0
cSetUsedBefore	ulong: bytes	59193472
gcId	uint	14
regionsFreed	uint	29
startTime	long: millis	1283648291

ObjectCountAfterGC

startTime 11 17 21 22

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	780
gcId	uint	1
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	jdk/jfr/ValueDescriptor
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/jdk.jfr
name	string	jdk.jfr
version	string	21-ea
name	string	jdk/jfr
startTime	long: millis	403164583
totalSize	ulong: bytes	31200

count	long	288786
gcId	uint	36
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/HashMap$Node
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21-ea
name	string	java/util
startTime	long: millis	4301053250
totalSize	ulong: bytes	9241152

count	long	280476
gcId	uint	21
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-ea
name	string	java/net
hidden	boolean	false
modifiers	int	49
name	string	akka/actor/ChildActorPath
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21-ea
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	akka/actor
startTime	long: millis	10525222291
totalSize	ulong: bytes	8975232

G1EvacuationYoungStatistics

default profiling startTime 11 17 21 22

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	16451166541
statistics	G1EvacuationStatistics
allocated	ulong: bytes	79691776
directAllocated	ulong: bytes	0
failureUsed	ulong: bytes	0
failureWaste	ulong: bytes	0
gcId	uint	50
regionEndWaste	ulong: bytes	0
regionsRefilled	uint: bytes	38
undoWaste	ulong: bytes	0
used	ulong: bytes	78171640
wasted	ulong: bytes	1864

G1EvacuationOldStatistics

default profiling startTime 11 17 21 22

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	24202935916
statistics	G1EvacuationStatistics
allocated	ulong: bytes	61865984
directAllocated	ulong: bytes	0
failureUsed	ulong: bytes	0
failureWaste	ulong: bytes	0
gcId	uint	61
regionEndWaste	ulong: bytes	0
regionsRefilled	uint: bytes	30
undoWaste	ulong: bytes	0
used	ulong: bytes	55922416
wasted	ulong: bytes	2464

G1BasicIHOP

default profiling startTime 11 17 21 22

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 initial mark to the first mixed GC

Examples 1

G1GC

currentOccupancy	ulong: bytes	1046274008
gcId	uint	67
lastMarkingDuration	long: millis	99
recentAllocationRate	double: bytes-per-second	6.100003698673559E7
recentMutatorAllocationSize	ulong: bytes	30408704
recentMutatorDuration	long: millis	498
startTime	long: millis	27361056625
targetOccupancy	ulong: bytes	3724541952
threshold	ulong: bytes	1676043878
thresholdPercentage	float: percentage	0.45

G1AdaptiveIHOP

default profiling startTime 11 17 21 22

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 initial mark to the first mixed GC
predictionActive	boolean	Prediction Active Indicates whether the adaptive IHOP prediction is active

Examples 1

G1GC

additionalBufferSize	ulong: bytes	209715200
currentOccupancy	ulong: bytes	98927200
gcId	uint	102
ihopTargetOccupancy	ulong: bytes	332713164
predictedAllocationRate	double: bytes-per-second	1.0504112360672468E8
predictedMarkingDuration	long: millis	198
predictionActive	boolean	false
startTime	long: millis	43949908750
threshold	ulong: bytes	157600972
thresholdPercentage	float: percentage	0.47368422

PromoteObjectInNewPLAB

profiling startTime eventThread 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC

Missing in: SerialGC, ShenandoahGC, ZGC

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

Configuration	enabled
default	false
profiling	true

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

Examples 2

ParallelGC
G1GC

gcId	uint	7
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	32
name	string	java/util/concurrent/ConcurrentHashMap$Node
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21-ea
name	string	java/util/concurrent
objectSize	ulong: bytes	32
plabSize	ulong: bytes	8176
startTime	long: millis	1100886208
tenured	boolean	true
tenuringAge	uint	5

gcId	uint	7
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/util/LinkedHashMap
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21-ea
name	string	java/util
objectSize	ulong: bytes	64
plabSize	ulong: bytes	92928
startTime	long: millis	1030613500
tenured	boolean	true
tenuringAge	uint	2

PromoteObjectOutsidePLAB

profiling startTime eventThread 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC

Missing in: SerialGC, ShenandoahGC, ZGC

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

Configuration	enabled
default	false
profiling	true

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

Examples 2

G1GC
ParallelGC

gcId	uint	75
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-ea
name	string	java/lang
objectSize	ulong: bytes	49840
startTime	long: millis	33045512958
tenured	boolean	false
tenuringAge	uint	0

gcId	uint	7
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	0
name	string	[C
package	Package	null
objectSize	ulong: bytes	4112
startTime	long: millis	1100418250
tenured	boolean	true
tenuringAge	uint	5

PromotionFailed

default profiling startTime 11 17 21 22

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 22

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 22

Category: Java Virtual Machine / GC / Detailed

Concurrent Mode failed

Configuration	enabled
default	true
profiling	true

Field	Type	Description
gcId	uint	GC Identifier

AllocationRequiringGC

startTime eventThread stackTrace 11 17 21 22

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	91
size	ulong: bytes	16
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	23
lineNumber	int	1070
method	Method
descriptor	string	(I)Ljava/lang/Integer;
hidden	boolean	false
modifiers	int	9
name	string	valueOf
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/lang/Integer
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21-ea
name	string	java/lang
type	FrameType	Inlined
		…
truncated	boolean	false
startTime	long: millis	107805465666

gcId	uint	55
size	ulong: bytes	2048
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	0
lineNumber	int	475
method	Method
descriptor	string	()Ljava/lang/String;
hidden	boolean	false
modifiers	int	1
name	string	toString
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/lang/StringBuilder
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21-ea
name	string	java/lang
type	FrameType	Inlined
		…
truncated	boolean	false
startTime	long: millis	20788145416

gcId	uint	41
size	ulong: bytes	216
stackTrace	StackTrace
frames	StackFrame
bytecodeIndex	int	6
lineNumber	int	3482
method	Method
descriptor	string	([Ljava/lang/Object;I)[Ljava/lang/Object;
hidden	boolean	false
modifiers	int	9
name	string	copyOf
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	49
name	string	java/util/Arrays
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21-ea
name	string	java/util
type	FrameType	Inlined
		…
truncated	boolean	false
startTime	long: millis	4844585041

TenuringDistribution

default profiling startTime 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, SerialGC

Missing in: ParallelGC, ShenandoahGC, ZGC

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

Configuration	enabled
default	true
profiling	true

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

Examples 2

G1GC
SerialGC

age	uint	2
gcId	uint	5
size	ulong: bytes	472928
startTime	long: millis	1007362375

age	uint	13
gcId	uint	2
size	ulong: bytes	0
startTime	long: millis	898712041

G1HeapRegionTypeChange

startTime 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Information about a G1 heap region type change

Configuration	enabled
default	false
profiling	false

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

Examples 1

G1GC

from	G1HeapRegionType	Eden
index	uint	7
start	ulong: address	30079451136
startTime	long: millis	1007283250
to	G1HeapRegionType	Free
used	ulong: bytes	0

ObjectCount

startTime every chunk 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

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

Configuration	enabled	period
default	false	everyChunk
profiling	false	everyChunk

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

Examples 3

count	long	2243
gcId	uint	1
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	48
name	string	java/util/ImmutableCollections$List12
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21-ea
name	string	java/util
startTime	long: millis	403164583
totalSize	ulong: bytes	53832

count	long	1813
gcId	uint	60
objectClass	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	0
name	string	[Ljava/util/HashMap$Node;
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21-ea
name	string	java/util
startTime	long: millis	6567851208
totalSize	ulong: bytes	2319928

count	long	280476
gcId	uint	21
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-ea
name	string	java/net
hidden	boolean	false
modifiers	int	49
name	string	akka/actor/ChildActorPath
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	null
type	Class
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
hidden	boolean	false
modifiers	int	33
name	string	java/net/URLClassLoader
package	Package
exported	boolean	true
module	Module
classLoader	ClassLoader
name	string	bootstrap
type	Class	null
location	string	jrt:/java.base
name	string	java.base
version	string	21-ea
name	string	java/net
location	string	null
name	string	null
version	string	null
name	string	akka/actor
startTime	long: millis	10525222291
totalSize	ulong: bytes	8975232

G1HeapRegionInformation

startTime duration every chunk 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Information about a specific heap region in the G1 GC

Configuration	enabled	period
default	false	everyChunk
profiling	false	everyChunk

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

Examples 1

G1GC

index	uint	5
start	ulong: address	30075256832
startTime	long: millis	406845375
type	G1HeapRegionType	Free
used	ulong: bytes	0

ZPageAllocation

experimental default profiling startTime duration eventThread 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Allocation of a ZPage

Configuration	enabled	threshold
default	true	10 ms
profiling	true	10 ms

Field	Type	Description
pageSize	ulong: bytes 11 until JDK 15	Page Size
usedAfter	ulong: bytes 11 until JDK 15	Used After
freeAfter	ulong: bytes 11 until JDK 15	Free After
inCacheAfter	ulong: bytes 11 until JDK 15	In Cache After
nonBlocking	boolean	Non-blocking
noReserve	boolean 11 until JDK 16	No Reserve

Examples 1

nonBlocking	boolean	false
startTime	long: millis	3031109375

ZThreadPhase

experimental default profiling startTime duration eventThread 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

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

Configuration	enabled	threshold
default	true	0 ms
profiling	true	0 ms

Field	Type	Description
gcId	uint	GC Identifier
name	string	Name

Examples 1

gcId	uint	5
name	string	Concurrent Mark Try Terminate
startTime	long: millis	3642709791

ZStatisticsCounter

experimental startTime duration eventThread 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

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

Configuration	enabled	threshold
default	false	0 ms
profiling	false	0 ms

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

Examples 1

id	ZStatisticsCounterType	Page Cache Hit L1
increment	ulong	1
startTime	long: millis	1224545250
value	ulong	8

ZStatisticsSampler

experimental startTime duration eventThread 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

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

Configuration	enabled	threshold
default	false	0 ms
profiling	false	0 ms

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

Examples 1

id	ZStatisticsSamplerType	Pause Relocate Start
startTime	long: millis	364401416
value	ulong	9833

ShenandoahHeapRegionStateChange

startTime 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: ShenandoahGC

Missing in: G1GC, ParallelGC, SerialGC, ZGC

Information about a Shenandoah heap region state change

Configuration	enabled
default	false
profiling	false

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

Examples 1

ShenandoahGC

from	ShenandoahHeapRegionState	Empty Committed
index	uint	211
start	ulong: address	30507270144
startTime	long: millis	763059807083
to	ShenandoahHeapRegionState	Humongous Continuation
used	ulong: bytes	0

ShenandoahHeapRegionInformation

startTime duration every chunk 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: ShenandoahGC

Missing in: G1GC, ParallelGC, SerialGC, ZGC

Information about a specific heap region in the Shenandoah GC

Configuration	enabled	period
default	false	everyChunk
profiling	false	everyChunk

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

Examples 1

ShenandoahGC

index	uint	92
start	ulong: address	30257709056
startTime	long: millis	760436296542
state	ShenandoahHeapRegionState	Regular
used	ulong: bytes	2097152

JVM: GC: Heap

GCHeapSummary

default profiling startTime 11 17 21 22

Category: Java Virtual Machine / GC / Heap

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

Configuration	enabled
default	true
profiling	true

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

Examples 3

gcId	uint	46
heapSpace	VirtualSpace
committedEnd	ulong: address	31746686976
committedSize	ulong: bytes	1681915904
reservedEnd	ulong: address	34359738368
reservedSize	ulong: bytes	4294967296
start	ulong: address	30064771072
heapUsed	ulong: bytes	437082680
startTime	long: millis	14193419916
when	GCWhen	After GC

gcId	uint	13
heapSpace	VirtualSpace
committedEnd	ulong: address	30324359168
committedSize	ulong: bytes	259588096
reservedEnd	ulong: address	34359738368
reservedSize	ulong: bytes	4294967296
start	ulong: address	30064771072
heapUsed	ulong: bytes	162497384
startTime	long: millis	1520133375
when	GCWhen	Before GC

gcId	uint	46
heapSpace	VirtualSpace
committedEnd	ulong: address	31846301696
committedSize	ulong: bytes	1781530624
reservedEnd	ulong: address	34359738368
reservedSize	ulong: bytes	4294967296
start	ulong: address	30064771072
heapUsed	ulong: bytes	181215264
startTime	long: millis	35280240791
when	GCWhen	After GC

MetaspaceSummary

default profiling startTime 11 17 21 22

Category: Java Virtual Machine / GC / Heap

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

Configuration	enabled
default	true
profiling	true

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

Examples 3

classSpace	MetaspaceSizes
committed	ulong: bytes	1835008
reserved	ulong: bytes	1073741824
used	ulong: bytes	1707376
dataSpace	MetaspaceSizes
committed	ulong: bytes	12255232
reserved	ulong: bytes	67108864
used	ulong: bytes	12092064
gcId	uint	13
gcThreshold	ulong: bytes	22740992
metaspace	MetaspaceSizes
committed	ulong: bytes	14090240
reserved	ulong: bytes	1140850688
used	ulong: bytes	13799440
startTime	long: millis	1525122958
when	GCWhen	After GC

classSpace	MetaspaceSizes
committed	ulong: bytes	1507328
reserved	ulong: bytes	1073741824
used	ulong: bytes	1441928
dataSpace	MetaspaceSizes
committed	ulong: bytes	10092544
reserved	ulong: bytes	67108864
used	ulong: bytes	9960408
gcId	uint	4
gcThreshold	ulong: bytes	22020096
metaspace	MetaspaceSizes
committed	ulong: bytes	11599872
reserved	ulong: bytes	1140850688
used	ulong: bytes	11402336
startTime	long: millis	961679166
when	GCWhen	Before GC

classSpace	MetaspaceSizes
committed	ulong: bytes	3997696
reserved	ulong: bytes	1073741824
used	ulong: bytes	3851688
dataSpace	MetaspaceSizes
committed	ulong: bytes	27000832
reserved	ulong: bytes	67108864
used	ulong: bytes	26817232
gcId	uint	48
gcThreshold	ulong: bytes	51904512
metaspace	MetaspaceSizes
committed	ulong: bytes	30998528
reserved	ulong: bytes	1140850688
used	ulong: bytes	30668920
startTime	long: millis	36515393166
when	GCWhen	Before GC

PSHeapSummary

default profiling startTime 11 17 21 22

Category: Java Virtual Machine / GC / Heap

Appearing in: ParallelGC

Missing in: G1GC, SerialGC, ShenandoahGC, ZGC

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

Configuration	enabled
default	true
profiling	true

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

Examples 1

ParallelGC

edenSpace	ObjectSpace
end	ulong: address	33923530752
size	ulong: bytes	995098624
start	ulong: address	32928432128
used	ulong: bytes	995098624
fromSpace	ObjectSpace
end	ulong: address	34072428544
size	ulong: bytes	148897792
start	ulong: address	33923530752
used	ulong: bytes	148570176
gcId