Introduction

The following are the events for the OpenJDK 23 (jdk-23+5, 17-January-2024). The events are collected from the event configuration and the source code. Visit jfreventcollector for more information. this is also the place you can contribute additional event descriptions, if you don't want to contribute them directly to the OpenJDK. The site generator lives on GitHub too.

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

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

Flight Recorder

DumpReason

default profiling startTime 11 17 21 22 23

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 23

Category: Flight Recorder

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

Configuration enabled
default true
profiling true

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

Flush

experimental startTime duration 14 17 21 22 23

Category: Flight Recorder

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

Configuration enabled threshold
default false 0 ns
profiling false 0 ns

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

Examples 3
elements ulong
4168
flushId ulong
74
size ulong: bytes
1182006
startTime long: millis
76320043292
elements ulong
2012
flushId ulong
65
size ulong: bytes
1064887
startTime long: millis
68543204125
elements ulong
3019
flushId ulong
28
size ulong: bytes
1300045
startTime long: millis
33120943500

ActiveRecording

default profiling startTime duration stackTrace 11 17 21 22 23

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

Category: Flight Recorder

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

Configuration enabled
default true
profiling true

Field Type Description
id long Id
name string Name Consider contributing a description to jfreventcollector.
destination string Destination Consider contributing a description to jfreventcollector.
disk boolean 21+ To Disk
maxAge long: millis Max Age
flushInterval long: millis 14+ Flush Interval
maxSize long: bytes Max Size
recordingStart long: epochmillis Start Time
recordingDuration long: millis Recording Duration

Examples 3
destination string
[...]/code/experiments/jfreventcollector/jfr/sample_UseSerialGC.jfr
disk boolean
true
flushInterval long: millis
1000
id long
1
maxAge long: millis
9223372036854775807
maxSize long: bytes
262144000
name string
1
recordingDuration long: millis
9223372036854775807
recordingStart long: epochmillis
1702899981921
stackTrace StackTrace
null
startTime long: millis
52080411375
destination string
[...]/code/experiments/jfreventcollector/jfr/sample_UseParallelGC.jfr
disk boolean
true
flushInterval long: millis
1000
id long
1
maxAge long: millis
9223372036854775807
maxSize long: bytes
262144000
name string
1
recordingDuration long: millis
9223372036854775807
recordingStart long: epochmillis
1702899886817
stackTrace StackTrace
null
startTime long: millis
17888392958
destination string
[...]/code/experiments/jfreventcollector/jfr/sample_UseG1GC.jfr
disk boolean
true
flushInterval long: millis
1000
id long
1
maxAge long: millis
9223372036854775807
maxSize long: bytes
262144000
name string
1
recordingDuration long: millis
9223372036854775807
recordingStart long: epochmillis
1702902685041
stackTrace StackTrace
null
startTime long: millis
62987307250

ActiveSetting

default profiling startTime duration stackTrace 11 17 21 22 23

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
36
name string
enabled
stackTrace StackTrace
null
startTime long: millis
416785542
value string
true
id long
10
name string
enabled
stackTrace StackTrace
null
startTime long: millis
669832834
value string
true
id long
45
name string
enabled
stackTrace StackTrace
null
startTime long: millis
360834042
value string
true

JVM

JVMInformation

default profiling startTime duration endchunk 11 17 21 22 23

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_UseG1GC.jfr,settings=[...]/code/experiments/jfreventcollector/.cache/jfc.jfc -XX:+UseG1GC
jvmFlags string
null
jvmName string
OpenJDK 64-Bit Server VM
jvmStartTime long: epochmillis
1702902684442
jvmVersion string
OpenJDK 64-Bit Server VM (21.0.1+12-LTS) for bsd-aarch64 JRE (21.0.1+12-LTS), built on 2023-10-17T00:00:00Z by "admin" with clang Apple LLVM 12.0.0 (clang-1200.0.32.29)
pid long
21922
startTime long: millis
12862175084
javaArguments string
[...]/code/experiments/jfreventcollector/.cache/renaissance.jar -t 5 -r 1 all
jvmArguments string
-XX:StartFlightRecording=filename=[...]/code/experiments/jfreventcollector/jfr/sample_UseParallelGC.jfr,settings=[...]/code/experiments/jfreventcollector/.cache/jfc.jfc -XX:+UseParallelGC
jvmFlags string
null
jvmName string
OpenJDK 64-Bit Server VM
jvmStartTime long: epochmillis
1702899886436
jvmVersion string
OpenJDK 64-Bit Server VM (21.0.1+12-LTS) for bsd-aarch64 JRE (21.0.1+12-LTS), built on 2023-10-17T00:00:00Z by "admin" with clang Apple LLVM 12.0.0 (clang-1200.0.32.29)
pid long
13981
startTime long: millis
75084757333
javaArguments string
[...]/code/experiments/jfreventcollector/.cache/renaissance.jar -t 5 -r 1 all
jvmArguments string
-XX:StartFlightRecording=filename=[...]/code/experiments/jfreventcollector/jfr/sample_UseSerialGC.jfr,settings=[...]/code/experiments/jfreventcollector/.cache/jfc.jfc -XX:+UseSerialGC
jvmFlags string
null
jvmName string
OpenJDK 64-Bit Server VM
jvmStartTime long: epochmillis
1702899981604
jvmVersion string
OpenJDK 64-Bit Server VM (21.0.1+12-LTS) for bsd-aarch64 JRE (21.0.1+12-LTS), built on 2023-10-17T00:00:00Z by "admin" with clang Apple LLVM 12.0.0 (clang-1200.0.32.29)
pid long
14273
startTime long: millis
52080815958

InitialSystemProperty

default profiling startTime endchunk 11 17 21 22 23

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
sun.java.command
startTime long: millis
60343487417
value string
[...]/code/experiments/jfreventcollector/.cache/renaissance.jar -t 5 -r 1 all
key string
java.vm.vendor
startTime long: millis
672946334
value string
Eclipse Adoptium
key string
java.vm.specification.name
startTime long: millis
364247417
value string
Java Virtual Machine Specification

JVM: Class Loading

ClassLoad

startTime duration eventThread stackTrace 11 17 21 22 23

Category: Java Virtual Machine / Class Loading

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

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

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

Examples 3
definingClassLoader ClassLoader
name string
bootstrap
type Class
null
initiatingClassLoader ClassLoader
name string
bootstrap
type Class
null
loadedClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1057
name string
java/util/spi/LocaleServiceProvider
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/util/spi
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
181
method Method
descriptor string
(Ljava/util/Locale;)Ljava/text/DecimalFormatSymbols;
hidden boolean
false
modifiers int
25
name string
getInstance
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/text/DecimalFormatSymbols
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/text
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
726106000
definingClassLoader ClassLoader
name string
app
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
32
name string
jdk/internal/loader/ClassLoaders$AppClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
jdk/internal/loader
initiatingClassLoader ClassLoader
name string
app
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
32
name string
jdk/internal/loader/ClassLoaders$AppClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
jdk/internal/loader
loadedClass Class
classLoader ClassLoader
name string
app
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
32
name string
jdk/internal/loader/ClassLoaders$AppClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
jdk/internal/loader
hidden boolean
false
modifiers int
48
name string
org/renaissance/core/Launcher$LaunchException
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
app
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
32
name string
jdk/internal/loader/ClassLoaders$AppClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
jdk/internal/loader
location string
null
name string
null
version string
null
name string
org/renaissance/core
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(Z)[Ljava/lang/reflect/Method;
hidden boolean
false
modifiers int
258
name string
getDeclaredMethods0
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
49
name string
java/lang/Class
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
389941375
definingClassLoader ClassLoader
name string
bootstrap
type Class
null
initiatingClassLoader ClassLoader
name string
bootstrap
type Class
null
loadedClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
32
name string
jdk/internal/loader/URLClassPath$JarLoader$2
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
jdk/internal/loader
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
60
lineNumber int
842
method Method
descriptor string
(Ljava/lang/String;ZLjava/util/jar/JarEntry;)Ljdk/internal/loader/Resource;
hidden boolean
false
modifiers int
0
name string
checkResource
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
32
name string
jdk/internal/loader/URLClassPath$JarLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
jdk/internal/loader
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
446620792

ClassDefine

startTime eventThread stackTrace 11 17 21 22 23

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
1537
name string
sun/util/logging/PlatformLogger$Bridge
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
sun/util/logging
definingClassLoader ClassLoader
name string
bootstrap
type Class
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
10
lineNumber int
66
method Method
descriptor string
()V
hidden boolean
false
modifiers int
1
name string
<init>
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/util/logging/SimpleFormatter
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.logging
name string
java.logging
version string
21.0.1
name string
java/util/logging
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
394108208
definedClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1057
name string
java/security/PermissionCollection
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/security
definingClassLoader ClassLoader
name string
bootstrap
type Class
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
1008
method Method
descriptor string
(Ljava/security/CodeSource;)Ljava/security/PermissionCollection;
hidden boolean
false
modifiers int
4
name string
getPermissions
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
jdk/internal/loader/BuiltinClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
jdk/internal/loader
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
448087792
definedClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1057
name string
sun/util/resources/Bundles
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
sun/util/resources
definingClassLoader ClassLoader
name string
bootstrap
type Class
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
11
lineNumber int
185
method Method
descriptor string
()Ljava/util/ResourceBundle;
hidden boolean
false
modifiers int
1
name string
run
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
32
name string
sun/util/resources/LocaleData$1
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
sun/util/resources
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
737109042

ClassRedefinition

default profiling startTime 15 17 21 22 23

Category: Java Virtual Machine / Class Loading

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

Configuration enabled
default true
profiling true

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

RedefineClasses

default profiling startTime duration eventThread stackTrace 15 17 21 22 23

Category: Java Virtual Machine / Class Loading

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

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

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

RetransformClasses

default profiling startTime duration eventThread stackTrace 15 17 21 22 23

Category: Java Virtual Machine / Class Loading

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

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

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

ClassUnload

startTime eventThread 11 17 21 22 23

Category: Java Virtual Machine / Class Loading

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

Configuration enabled
default false
profiling false

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

Examples 3
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
startTime long: millis
4558833292
unloadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
hidden boolean
false
modifiers int
32
name string
org/sparkproject/guava/collect/Lists$Partition
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
org/sparkproject/guava/collect
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
startTime long: millis
5993885875
unloadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
hidden boolean
false
modifiers int
1537
name string
scala/collection/SortedSetOps
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
scala/collection
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
startTime long: millis
3889427958
unloadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
hidden boolean
true
modifiers int
4144
name string
org.apache.spark.internal.config.package$$$Lambda+0x0000000800375328/2017530134
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/internal/config

JVM: Code Cache

CodeCacheFull

default profiling startTime eventThread 11 17 21 22 23

Category: Java Virtual Machine / Code Cache

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

Configuration enabled
default true
profiling true

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

CodeCacheStatistics

default profiling startTime everychunk 11 17 21 22 23

Category: Java Virtual Machine / Code Cache

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

Configuration enabled period
default true everyChunk
profiling true everyChunk

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

Examples 3
adaptorCount int
0
codeBlobType CodeBlobType
CodeHeap 'non-profiled nmethods'
entryCount int
2089
fullCount int
0
methodCount int
2089
reservedTopAddress ulong: address
5217714176
startAddress ulong: address
5094801408
startTime long: millis
30479687875
unallocatedCapacity ulong: bytes
118741888
adaptorCount int
470
codeBlobType CodeBlobType
CodeHeap 'non-nmethods'
entryCount int
561
fullCount int
0
methodCount int
0
reservedTopAddress ulong: address
4610097152
startAddress ulong: address
4604248064
startTime long: millis
15845298667
unallocatedCapacity ulong: bytes
4478720
adaptorCount int
0
codeBlobType CodeBlobType
CodeHeap 'non-profiled nmethods'
entryCount int
3940
fullCount int
0
methodCount int
3940
reservedTopAddress ulong: address
4771921920
startAddress ulong: address
4649009152
startTime long: millis
50917387792
unallocatedCapacity ulong: bytes
112434816

CodeCacheConfiguration

default profiling startTime endchunk 11 17 21 22 23

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
5217714176
startAddress ulong: address
4966055936
startTime long: millis
39268371625
expansionSize ulong: bytes
65536
initialSize ulong: bytes
2555904
minBlockLength ulong: bytes
6
nonNMethodSize ulong: bytes
5839564
nonProfiledSize ulong: bytes
122909338
profiledSize ulong: bytes
122909338
reservedSize ulong: bytes
251658240
reservedTopAddress ulong: address
4733009920
startAddress ulong: address
4481351680
startTime long: millis
75962738417
expansionSize ulong: bytes
65536
initialSize ulong: bytes
2555904
minBlockLength ulong: bytes
6
nonNMethodSize ulong: bytes
5839564
nonProfiledSize ulong: bytes
122909338
profiledSize ulong: bytes
122909338
reservedSize ulong: bytes
251658240
reservedTopAddress ulong: address
4771921920
startAddress ulong: address
4520263680
startTime long: millis
12863160917

JVM: Compiler

JITRestart

default profiling startTime eventThread 17 21 22 23

Category: Java Virtual Machine / Compiler

Restart of the JIT compilers after they were stopped

Configuration enabled
default true
profiling true

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

Compilation

default profiling startTime duration eventThread 11 17 21 22 23

Category: Java Virtual Machine / Compiler

Results of method compilation attempts

Configuration enabled threshold
default true 1000 ms
profiling true 100 ms

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

Examples 3
codeSize ulong: bytes
42592
compileId int
14574
compileLevel ushort
4
compiler CompilerType
c2
inlinedBytes ulong: bytes
5114
isOsr boolean
false
method Method
descriptor string
(Ljava/net/SocketAddress;)V
hidden boolean
false
modifiers int
1
name string
<init>
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
hidden boolean
false
modifiers int
33
name string
com/twitter/finagle/netty4/transport/ChannelTransport$NoStackTraceChannelClosedException
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
com/twitter/finagle/netty4/transport
startTime long: millis
30853801584
succeded boolean
true
codeSize ulong: bytes
5968
compileId int
6507
compileLevel ushort
4
compiler CompilerType
c2
inlinedBytes ulong: bytes
1014
isOsr boolean
false
method Method
descriptor string
(Lscala/util/Try;)Z
hidden boolean
false
modifiers int
17
name string
tryComplete
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
hidden boolean
false
modifiers int
33
name string
scala/concurrent/impl/Promise$DefaultPromise
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
scala/concurrent/impl
startTime long: millis
11821463917
succeded boolean
true
codeSize ulong: bytes
15728
compileId int
7029
compileLevel ushort
4
compiler CompilerType
c2
inlinedBytes ulong: bytes
3022
isOsr boolean
false
method Method
descriptor string
(Lscala/Option;)V
hidden boolean
false
modifiers int
1
name string
create
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
hidden boolean
false
modifiers int
33
name string
akka/actor/ActorCell
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
akka/actor
startTime long: millis
15026860958
succeded boolean
true

CompilerPhase

default profiling startTime duration eventThread 11 17 21 22 23

Category: Java Virtual Machine / Compiler

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

Configuration enabled threshold
default true 60 s
profiling true 10 s

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

CompilationFailure

profiling startTime eventThread 11 17 21 22 23

Category: Java Virtual Machine / Compiler

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

Configuration enabled
default false
profiling true

Field Type Description
failureMessage string Failure Message
compileId int Compilation Identifier

Examples 3
compileId int
22930
failureMessage string
concurrent class loading
startTime long: millis
74091028458
compileId int
22775
failureMessage string
concurrent class loading
startTime long: millis
57760414792
compileId int
23245
failureMessage string
concurrent class loading
startTime long: millis
82998780708

CompilerInlining

startTime eventThread 11 17 21 22 23

Category: Java Virtual Machine / Compiler / Optimization

Describes the result of a method inlining attempt

Configuration enabled
default false
profiling false

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

Examples 3
bci int
1
callee CalleeMethod
descriptor string
()V
name string
<init>
type string
java/util/AbstractCollection
caller Method
descriptor string
()V
hidden boolean
false
modifiers int
4
name string
<init>
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1057
name string
java/util/AbstractSet
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/util
compileId int
1452
message string
inline
startTime long: millis
416108708
succeeded boolean
true
bci int
150
callee CalleeMethod
descriptor string
(B)V
name string
putUncheckedByte
type string
jdk/jfr/internal/event/EventWriter
caller Method
descriptor string
(J)V
hidden boolean
false
modifiers int
2
name string
putUncheckedLong
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
49
name string
jdk/jfr/internal/event/EventWriter
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/jdk.jfr
name string
jdk.jfr
version string
21.0.1
name string
jdk/jfr/internal/event
compileId int
1486
message string
callee uses too much stack
startTime long: millis
670273334
succeeded boolean
false
bci int
2
callee CalleeMethod
descriptor string
(Ljava/lang/String;)Ljava/lang/AbstractStringBuilder;
name string
append
type string
java/lang/AbstractStringBuilder
caller Method
descriptor string
(Ljava/lang/String;)Ljava/lang/StringBuilder;
hidden boolean
false
modifiers int
1
name string
append
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
49
name string
java/lang/StringBuilder
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/lang
compileId int
1413
message string
callee is too large
startTime long: millis
359616125
succeeded boolean
false

Deoptimization

default profiling startTime eventThread stackTrace 14 17 21 22 23

Category: Java Virtual Machine / Compiler

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

Configuration enabled stackTrace
default true false
profiling true true

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

Examples 3
action DeoptimizationAction
reinterpret
bci int
55
compileId int
2689
compiler CompilerType
c2
instruction Bytecode
if_icmplt
lineNumber int
371
method Method
descriptor string
(Z[Z)Ljava/lang/String;
hidden boolean
false
modifiers int
2
name string
implReadLine
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/io/BufferedReader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/io
reason DeoptimizationReason
unstable_if
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
55
lineNumber int
371
method Method
descriptor string
(Z[Z)Ljava/lang/String;
hidden boolean
false
modifiers int
2
name string
implReadLine
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/io/BufferedReader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/io
type FrameType
Inlined
truncated boolean
false
startTime long: millis
1204479500
action DeoptimizationAction
reinterpret
bci int
13
compileId int
3187
compiler CompilerType
c2
instruction Bytecode
ifnonnull
lineNumber int
592
method Method
descriptor string
(Ljava/lang/Object;Ljava/util/function/Function;)Ljava/lang/Object;
hidden boolean
false
modifiers int
1
name string
computeIfAbsent
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/util/TreeMap
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/util
reason DeoptimizationReason
unstable_if
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
13
lineNumber int
592
method Method
descriptor string
(Ljava/lang/Object;Ljava/util/function/Function;)Ljava/lang/Object;
hidden boolean
false
modifiers int
1
name string
computeIfAbsent
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/util/TreeMap
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/util
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
2387586750
action DeoptimizationAction
maybe_recompile
bci int
19
compileId int
3184
compiler CompilerType
c2
instruction Bytecode
invokeinterface
lineNumber int
526
method Method
descriptor string
(Ljava/util/stream/Sink;Ljava/util/Spliterator;)Z
hidden boolean
false
modifiers int
16
name string
copyIntoWithCancel
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1056
name string
java/util/stream/AbstractPipeline
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/util/stream
reason DeoptimizationReason
class_check
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
19
lineNumber int
526
method Method
descriptor string
(Ljava/util/stream/Sink;Ljava/util/Spliterator;)Z
hidden boolean
false
modifiers int
16
name string
copyIntoWithCancel
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1056
name string
java/util/stream/AbstractPipeline
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/util/stream
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
2049351458

CompilerQueueUtilization

default profiling startTime duration everychunk 22 23

Category: Java Virtual Machine / Compiler

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

Configuration enabled period
default true 10 s
profiling true 5 s

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

CompilerStatistics

default profiling startTime everychunk 11 17 21 22 23

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
3
compileCount int
16845
invalidatedCount int
0
nmethodCodeSize ulong: bytes
20547976
nmethodsSize ulong: bytes
32037760
osrBytesCompiled ulong: bytes
0
osrCompileCount int
144
peakTimeSpent long: millis
953
standardBytesCompiled ulong: bytes
0
standardCompileCount int
16701
startTime long: millis
57096556750
totalTimeSpent long: millis
42423
bailoutCount int
2
compileCount int
5984
invalidatedCount int
0
nmethodCodeSize ulong: bytes
7335800
nmethodsSize ulong: bytes
11087960
osrBytesCompiled ulong: bytes
0
osrCompileCount int
66
peakTimeSpent long: millis
194
standardBytesCompiled ulong: bytes
0
standardCompileCount int
5918
startTime long: millis
9730697209
totalTimeSpent long: millis
6692
bailoutCount int
3
compileCount int
34137
invalidatedCount int
0
nmethodCodeSize ulong: bytes
43788632
nmethodsSize ulong: bytes
67440896
osrBytesCompiled ulong: bytes
0
osrCompileCount int
230
peakTimeSpent long: millis
1360
standardBytesCompiled ulong: bytes
0
standardCompileCount int
33907
startTime long: millis
96437423708
totalTimeSpent long: millis
82798

CompilerConfiguration

default profiling startTime endchunk 11 17 21 22 23

Category: Java Virtual Machine / Compiler

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

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
threadCount int Thread Count
tieredCompilation boolean Tiered Compilation
dynamicCompilerThreadCount boolean 20+ Uses Dynamic Number of Compiler Threads

Examples 3
dynamicCompilerThreadCount boolean
true
startTime long: millis
30519906375
threadCount int
4
tieredCompilation boolean
true
dynamicCompilerThreadCount boolean
true
startTime long: millis
36097498959
threadCount int
4
tieredCompilation boolean
true
dynamicCompilerThreadCount boolean
true
startTime long: millis
78960104208
threadCount int
4
tieredCompilation boolean
true

JVM: Diagnostics

SyncOnValueBasedClass

experimental default profiling startTime eventThread stackTrace 16 17 21 22 23

Category: Java Virtual Machine / Diagnostics

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

Configuration enabled stackTrace
default true true
profiling true true

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

HeapDump

default profiling startTime duration eventThread stackTrace 15 17 21 22 23

Category: Java Virtual Machine / Diagnostics

Information about a successfully written Java heap dump

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

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

JavaAgent

default profiling startTime endchunk 21 22 23

Category: Java Virtual Machine / Diagnostics

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

Configuration enabled period
default true endChunk
profiling true endChunk

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

NativeAgent

default profiling startTime endchunk 21 22 23

Category: Java Virtual Machine / Diagnostics

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

Configuration enabled period
default true endChunk
profiling true endChunk

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

JVM: Flag

IntFlagChanged

default profiling startTime 11 17 21 22 23

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 23

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 23

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 23

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 23

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 23

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 23

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 endchunk 11 17 21 22 23

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
JavaPriority3_To_OSPriority
origin FlagValueOrigin
Default
startTime long: millis
15845308542
value int
-1
name string
JavaPriority1_To_OSPriority
origin FlagValueOrigin
Default
startTime long: millis
676045417
value int
-1
name string
SoftwarePrefetchHintDistance
origin FlagValueOrigin
Default
startTime long: millis
17899846000
value int
384

UnsignedIntFlag

default profiling startTime duration endchunk 11 17 21 22 23

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
TypeProfileLevel
origin FlagValueOrigin
Default
startTime long: millis
15845316125
value uint
111
name string
TestCrashInErrorHandler
origin FlagValueOrigin
Default
startTime long: millis
60345413875
value uint
0
name string
G1ConcRefinementThreads
origin FlagValueOrigin
Ergonomic
startTime long: millis
50917396917
value uint
8

LongFlag

default profiling startTime duration endchunk 11 17 21 22 23

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
OptoPrologueNops
origin FlagValueOrigin
Default
startTime long: millis
676075625
value long
0
name string
Tier0BackedgeNotifyFreqLog
origin FlagValueOrigin
Default
startTime long: millis
364810667
value long
10
name string
LoopPercentProfileLimit
origin FlagValueOrigin
Default
startTime long: millis
423469500
value long
10

UnsignedLongFlag

default profiling startTime duration endchunk 11 17 21 22 23

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
CompressedClassSpaceSize
origin FlagValueOrigin
Default
startTime long: millis
676125042
value ulong
1073741824
name string
PLABWeight
origin FlagValueOrigin
Default
startTime long: millis
364823125
value ulong
75
name string
NewRatio
origin FlagValueOrigin
Default
startTime long: millis
423583083
value ulong
2

DoubleFlag

default profiling startTime duration endchunk 11 17 21 22 23

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
G1PeriodicGCSystemLoadThreshold
origin FlagValueOrigin
Default
startTime long: millis
364834792
value double
0.0
name string
SweeperThreshold
origin FlagValueOrigin
Default
startTime long: millis
423591417
value double
15.0
name string
G1PeriodicGCSystemLoadThreshold
origin FlagValueOrigin
Default
startTime long: millis
12863269334
value double
0.0

BooleanFlag

default profiling startTime duration endchunk 11 17 21 22 23

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
TimeLinearScan
origin FlagValueOrigin
Default
startTime long: millis
676156667
value boolean
false
name string
UseCompressedOops
origin FlagValueOrigin
Ergonomic
startTime long: millis
423593750
value boolean
true
name string
PrintBlockElimination
origin FlagValueOrigin
Default
startTime long: millis
364840083
value boolean
false

StringFlag

default profiling startTime duration endchunk 11 17 21 22 23

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
39268447667
value string
null
name string
PrintIdealGraphFile
origin FlagValueOrigin
Default
startTime long: millis
27602575875
value string
null
name string
NativeMemoryTracking
origin FlagValueOrigin
Default
startTime long: millis
40031307875
value string
off

JVM: GC: Collector

GarbageCollection

default profiling startTime duration eventThread 11 17 21 22 23

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
11
longestPause Tickspan
3109916
name GCName
ParallelScavenge
startTime long: millis
1870097042
sumOfPauses Tickspan
3109916
cause GCCause
G1 Evacuation Pause
gcId uint
77
longestPause Tickspan
21220042
name GCName
G1New
startTime long: millis
24640919042
sumOfPauses Tickspan
21220042
cause GCCause
Allocation Failure
gcId uint
82
longestPause Tickspan
72330333
name GCName
DefNew
startTime long: millis
12681501292
sumOfPauses Tickspan
72330333

SystemGC

default profiling startTime duration eventThread stackTrace 17 21 22 23

Category: Java Virtual Machine / GC / Collector

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

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

Field Type Description
invokedConcurrent boolean Invoked Concurrent

Examples 3
invokedConcurrent boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
()V
hidden boolean
false
modifiers int
257
name string
gc
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/lang/Runtime
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
56563641000
invokedConcurrent boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
()V
hidden boolean
false
modifiers int
257
name string
gc
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/lang/Runtime
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
5929602000
invokedConcurrent boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
()V
hidden boolean
false
modifiers int
257
name string
gc
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/lang/Runtime
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
36499479750

ParallelOldGarbageCollection

default profiling startTime duration 11 17 21 22 23

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
densePrefix ulong: address
30143938560
gcId uint
20
startTime long: millis
6765277208

YoungGarbageCollection

default profiling startTime duration 11 17 21 22 23

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
53
startTime long: millis
30479722417
tenuringThreshold uint
15
gcId uint
4
startTime long: millis
1128458542
tenuringThreshold uint
1
gcId uint
110
startTime long: millis
39655931459
tenuringThreshold uint
15

OldGarbageCollection

default profiling startTime duration 11 17 21 22 23

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
112
startTime long: millis
78662123208
gcId uint
61
startTime long: millis
6402641958
gcId uint
138
startTime long: millis
47853342459

G1GarbageCollection

default profiling startTime duration 11 17 21 22 23

Category: Java Virtual Machine / GC / Collector

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Extra information specific to G1 Young Garbage Collections

Configuration enabled threshold
default true 0 ms
profiling true 0 ms

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

Examples 1
gcId uint
86
startTime long: millis
30104926959
type G1YCType
Normal

ZYoungGarbageCollection

default profiling startTime duration eventThread 21 22 23

Category: Java Virtual Machine / GC / Collector

Extra information specific to ZGC Young Garbage Collections

Configuration enabled threshold
default true 0 ms
profiling true 0 ms

Field Type Description
gcId uint GC Identifier
tenuringThreshold uint Tenuring Threshold

ZOldGarbageCollection

default profiling startTime duration eventThread 21 22 23

Category: Java Virtual Machine / GC / Collector

Extra information specific to ZGC Old Garbage Collections

Configuration enabled threshold
default true 0 ms
profiling true 0 ms

Field Type Description
gcId uint GC Identifier

JVM: GC: Configuration

GCConfiguration

default profiling startTime duration endchunk 11 17 21 22 23

Category: Java Virtual Machine / GC / Configuration

The configuration of the garbage collector

Configuration enabled period
default true everyChunk
profiling true everyChunk

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

Examples 3
concurrentGCThreads uint
0
gcTimeRatio uint
99
isExplicitGCConcurrent boolean
false
isExplicitGCDisabled boolean
false
oldCollector GCName
SerialOld
parallelGCThreads uint
0
pauseTarget long: millis
-9223372036854775808
startTime long: millis
52070344583
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
26973384459
usesDynamicGCThreads boolean
true
youngCollector GCName
G1New
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
18250631375
usesDynamicGCThreads boolean
true
youngCollector GCName
ParallelScavenge

GCSurvivorConfiguration

default profiling startTime duration endchunk 11 17 21 22 23

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
50973330292
initialTenuringThreshold ubyte
7
maxTenuringThreshold ubyte
15
startTime long: millis
88354586500
initialTenuringThreshold ubyte
7
maxTenuringThreshold ubyte
15
startTime long: millis
436495750

GCTLABConfiguration

default profiling startTime duration endchunk 11 17 21 22 23

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
40220268250
tlabRefillWasteLimit ulong: bytes
64
usesTLABs boolean
true
minTLABSize ulong: bytes
2048
startTime long: millis
13055583875
tlabRefillWasteLimit ulong: bytes
64
usesTLABs boolean
true
minTLABSize ulong: bytes
2048
startTime long: millis
93887423208
tlabRefillWasteLimit ulong: bytes
64
usesTLABs boolean
true

GCHeapConfiguration

default profiling startTime duration endchunk 11 17 21 22 23

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
30690534667
usesCompressedOops boolean
true
compressedOopsMode NarrowOopMode
Zero based
heapAddressBits ubyte
32
initialSize ulong: bytes
268435456
maxSize ulong: bytes
4294967296
minSize ulong: bytes
8388608
objectAlignment ulong: bytes
8
startTime long: millis
60476333958
usesCompressedOops boolean
true
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
22231100584
usesCompressedOops boolean
true

YoungGenerationConfiguration

default profiling startTime duration endchunk 11 17 21 22 23

Category: Java Virtual Machine / GC / Configuration

The configuration of the young generation of the garbage collected heap

Configuration enabled period
default true beginChunk
profiling true beginChunk

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

Examples 3
maxSize ulong: bytes
1431633920
minSize ulong: bytes
89456640
newRatio uint
2
startTime long: millis
52241835708
maxSize ulong: bytes
1431306240
minSize ulong: bytes
89128960
newRatio uint
2
startTime long: millis
39413199875
maxSize ulong: bytes
2575302656
minSize ulong: bytes
1363144
newRatio uint
2
startTime long: millis
63145625959

JVM: GC: Detailed

ZThreadDebug

internal startTime duration eventThread 18 21 22 23

Category: Java Virtual Machine / GC / Detailed

Temporary latency measurements used during development and debugging of ZGC

Only valid for the ZGC.

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

G1MMU

default profiling startTime 11 17 21 22 23

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
gcId uint
18
gcTime long: millis
5
pauseTarget long: millis
200
startTime long: millis
2403934334
timeSlice long: millis
201

EvacuationInformation

default profiling startTime 11 17 21 22 23

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
allocationRegions uint
3
allocationRegionsUsedAfter ulong: bytes
5744896
allocationRegionsUsedBefore ulong: bytes
0
bytesCopied ulong: bytes
5744896
cSetRegions uint
84
cSetUsedAfter ulong: bytes
0
cSetUsedBefore ulong: bytes
175076992
gcId uint
17
regionsFreed uint
84
startTime long: millis
2325172042

ObjectCountAfterGC

startTime 11 17 21 22 23

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
9630
gcId uint
29
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
21.0.1
name string
java/util
startTime long: millis
7918533000
totalSize ulong: bytes
616320
count long
168
gcId uint
1
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
[I
package Package
null
startTime long: millis
865943958
totalSize ulong: bytes
108768
count long
96
gcId uint
3
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
[Ljava/util/concurrent/ConcurrentHashMap$Node;
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/util/concurrent
startTime long: millis
976302875
totalSize ulong: bytes
318272

G1EvacuationYoungStatistics

default profiling startTime 11 17 21 22 23

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
startTime long: millis
12094083709
statistics G1EvacuationStatistics
allocated ulong: bytes
100663296
directAllocated ulong: bytes
0
failureUsed ulong: bytes
0
failureWaste ulong: bytes
0
gcId uint
42
numDirectAllocated ulong
5
numPlabsFilled ulong
7504122885671534260
regionEndWaste ulong: bytes
0
regionsRefilled uint
48
undoWaste ulong: bytes
0
used ulong: bytes
98115104
wasted ulong: bytes
51240

G1EvacuationOldStatistics

default profiling startTime 11 17 21 22 23

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
startTime long: millis
22056141709
statistics G1EvacuationStatistics
allocated ulong: bytes
0
directAllocated ulong: bytes
0
failureUsed ulong: bytes
0
failureWaste ulong: bytes
0
gcId uint
64
numDirectAllocated ulong
6147041496
numPlabsFilled ulong
0
regionEndWaste ulong: bytes
0
regionsRefilled uint
0
undoWaste ulong: bytes
0
used ulong: bytes
0
wasted ulong: bytes
0

G1BasicIHOP

default profiling startTime 11 17 21 22 23

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Basic statistics related to current IHOP calculation

Configuration enabled
default true
profiling true

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

Examples 1
currentOccupancy ulong: bytes
6513440
gcId uint
6
lastMarkingDuration long: millis
0
recentAllocationRate double: bytes-per-second
0.0
recentMutatorAllocationSize ulong: bytes
0
recentMutatorDuration long: millis
425
startTime long: millis
1433723667
targetOccupancy ulong: bytes
142606336
threshold ulong: bytes
64172851
thresholdPercentage float: percentage
0.45

G1AdaptiveIHOP

default profiling startTime 11 17 21 22 23

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Statistics related to current adaptive IHOP calculation

Configuration enabled
default true
profiling true

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

Examples 1
additionalBufferSize ulong: bytes
346030080
currentOccupancy ulong: bytes
99528080
gcId uint
110
ihopTargetOccupancy ulong: bytes
547880960
predictedAllocationRate double: bytes-per-second
5.893234395981928E8
predictedMarkingDuration long: millis
338
predictionActive boolean
false
startTime long: millis
39657412542
threshold ulong: bytes
259522560
thresholdPercentage float: percentage
0.47368422

PromoteObjectInNewPLAB

profiling startTime eventThread 11 17 21 22 23

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC

Missing in: SerialGC, ShenandoahGC, ZGC

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

Configuration enabled
default false
profiling true

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

Examples 2
gcId uint
5
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
[B
package Package
null
objectSize ulong: bytes
24
plabSize ulong: bytes
8176
startTime long: millis
1164776667
tenured boolean
true
tenuringAge uint
1
gcId uint
3
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
49
name string
java/lang/Class
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/lang
objectSize ulong: bytes
112
plabSize ulong: bytes
6016
startTime long: millis
939916792
tenured boolean
true
tenuringAge uint
1

PromoteObjectOutsidePLAB

profiling startTime eventThread 11 17 21 22 23

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC

Missing in: SerialGC, ShenandoahGC, ZGC

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

Configuration enabled
default false
profiling true

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

Examples 2
gcId uint
2
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
[B
package Package
null
objectSize ulong: bytes
262064
startTime long: millis
912911542
tenured boolean
false
tenuringAge uint
0
gcId uint
14
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
[Ljava/lang/Object;
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/lang
objectSize ulong: bytes
7520
startTime long: millis
2184589833
tenured boolean
true
tenuringAge uint
1

PromotionFailed

default profiling startTime 11 17 21 22 23

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 23

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 23

Category: Java Virtual Machine / GC / Detailed

Concurrent Mode failed

Configuration enabled
default true
profiling true

Field Type Description
gcId uint GC Identifier

GCCPUTime

default profiling startTime 20 21 22 23

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

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

Configuration enabled
default true
profiling true

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

Examples 3
gcId uint
63
realTime ulong: nanos
0
startTime long: millis
21977190834
systemTime ulong: nanos
0
userTime ulong: nanos
10000000
gcId uint
37
realTime ulong: nanos
179999828
startTime long: millis
4005068542
systemTime ulong: nanos
0
userTime ulong: nanos
169999999
gcId uint
52
realTime ulong: nanos
120000123
startTime long: millis
29788598500
systemTime ulong: nanos
9999999
userTime ulong: nanos
480000000

AllocationRequiringGC

startTime eventThread stackTrace 11 17 21 22 23

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
18
size ulong: bytes
702352
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
48
lineNumber int
232
method Method
descriptor string
(Ljava/util/stream/AbstractPipeline;JJ)Ljava/util/stream/IntStream;
hidden boolean
false
modifiers int
9
name string
makeInt
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
48
name string
java/util/stream/SliceOps
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/util/stream
type FrameType
Inlined
truncated boolean
false
startTime long: millis
2401078792
gcId uint
26
size ulong: bytes
32
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
41
lineNumber int
204
method Method
descriptor string
(Lakka/actor/ActorSystemImpl;Lakka/actor/RepointableActorRef;Lakka/actor/Props;Lakka/actor/InternalActorRef;)V
hidden boolean
false
modifiers int
1
name string
<init>
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
hidden boolean
false
modifiers int
33
name string
akka/actor/UnstartedCell
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
akka/actor
type FrameType
Inlined
truncated boolean
false
startTime long: millis
16759119583
gcId uint
24
size ulong: bytes
24
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
1
lineNumber int
661
method Method
descriptor string
()[J
hidden boolean
false
modifiers int
4106
name string
lambda$summingLong$22
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
49
name string
java/util/stream/Collectors
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/util/stream
type FrameType
Inlined
truncated boolean
false
startTime long: millis
1883693333

TenuringDistribution

default profiling startTime 11 17 21 22 23

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
age uint
9
gcId uint
2
size ulong: bytes
0
startTime long: millis
1015474333
age uint
7
gcId uint
5
size ulong: bytes
0
startTime long: millis
1005682000

G1HeapRegionTypeChange

startTime 11 17 21 22 23

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
from G1HeapRegionType
Eden
index uint
62
start ulong: address
30194794496
startTime long: millis
1433290209
to G1HeapRegionType
Free
used ulong: bytes
0

ObjectCount

startTime everychunk 11 17 21 22 23

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
561
gcId uint
16
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
[I
package Package
null
startTime long: millis
4573757000
totalSize ulong: bytes
1506072
count long
538
gcId uint
0
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
[Ljava/lang/String;
package Package
exported boolean
true