Introduction

The following are the events for the OpenJDK 12 (jdk-12.0.2+10, 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

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.
maxAge long: millis Max Age
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
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
40015959333
destination string
[...]/code/experiments/jfreventcollector/jfr/sample_UseG1GC.jfr
id long
1
maxAge long: millis
9223372036854775807
maxSize long: bytes
0
name string
1
recordingDuration long: millis
9223372036854775807
recordingStart long: epochmillis
1702902685041
stackTrace StackTrace
null
startTime long: millis
669832834
destination string
[...]/code/experiments/jfreventcollector/jfr/sample_UseParallelGC.jfr
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
39217883625

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
63
name string
enabled
stackTrace StackTrace
null
startTime long: millis
416785542
value string
true
id long
13
name string
threshold
stackTrace StackTrace
null
startTime long: millis
360834042
value string
10 ms
id long
60
name string
enabled
stackTrace StackTrace
null
startTime long: millis
669832834
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_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
364229792
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
422523083

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
java.vm.specification.vendor
startTime long: millis
22148538625
value string
Oracle Corporation
key string
java.vm.specification.vendor
startTime long: millis
364247417
value string
Oracle Corporation
key string
java.vm.specification.version
startTime long: millis
39218561500
value string
21

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
16432
name string
jdk/jfr/internal/Utils$ThrottleUnit
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/jdk.jfr
name string
jdk.jfr
version string
21.0.1
name string
jdk/jfr/internal
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
26
lineNumber int
289
method Method
descriptor string
(Ljava/lang/String;)J
hidden boolean
false
modifiers int
9
name string
parseThrottleValue
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
49
name string
jdk/jfr/internal/Utils
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/jdk.jfr
name string
jdk.jfr
version string
21.0.1
name string
jdk/jfr/internal
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
412508792
definingClassLoader ClassLoader
name string
bootstrap
type Class
null
initiatingClassLoader ClassLoader
name string
app
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
32
name string
jdk/internal/loader/ClassLoaders$AppClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
jdk/internal/loader
loadedClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/io/ByteArrayOutputStream
package Package
exported boolean
true
module Module
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
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
390436375
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
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
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
22
lineNumber int
2032
method Method
descriptor string
(Ljava/util/Locale;)Ljava/text/DecimalFormatSymbols;
hidden boolean
false
modifiers int
10
name string
getDecimalFormatSymbols
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
49
name string
java/util/Formatter
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/util
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
725916750

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
33
name string
jdk/internal/module/ModulePatcher$PatchedModuleReader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
jdk/internal/module
definingClassLoader ClassLoader
name string
bootstrap
type Class
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
35
lineNumber int
802
method Method
descriptor string
(Ljava/lang/String;Ljdk/internal/loader/BuiltinClassLoader$LoadedModule;)Ljava/lang/Class;
hidden boolean
false
modifiers int
2
name string
defineClass
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
478350125
definedClass 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
21.0.1
name string
sun/launcher
definingClassLoader ClassLoader
name string
bootstrap
type Class
null
stackTrace StackTrace
null
startTime long: millis
380335375
definedClass 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
definingClassLoader ClassLoader
name string
bootstrap
type Class
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
22
lineNumber int
2032
method Method
descriptor string
(Ljava/util/Locale;)Ljava/text/DecimalFormatSymbols;
hidden boolean
false
modifiers int
10
name string
getDecimalFormatSymbols
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
49
name string
java/util/Formatter
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/util
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
726039417

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
5993906709
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$$$Lambda+0x0000000800372d48/1179689991
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/internal/config
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
startTime long: millis
4558738292
unloadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
hidden boolean
true
modifiers int
4144
name string
org.apache.spark.internal.config.package$$$Lambda+0x0000000800374ab8/806572546
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/internal/config
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
startTime long: millis
3889446375
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/runtime/java8/JFunction1$mcZI$sp
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/runtime/java8

JVM: Code Cache

CodeCacheFull

default profiling startTime eventThread 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
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 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
402
fullCount int
0
methodCount int
402
reservedTopAddress ulong: address
4771921920
startAddress ulong: address
4649009152
startTime long: millis
676035250
unallocatedCapacity ulong: bytes
122454400
adaptorCount int
0
codeBlobType CodeBlobType
CodeHeap 'profiled nmethods'
entryCount int
4980
fullCount int
0
methodCount int
4980
reservedTopAddress ulong: address
5088952320
startAddress ulong: address
4966055936
startTime long: millis
94083575458
unallocatedCapacity ulong: bytes
109975808
adaptorCount int
0
codeBlobType CodeBlobType
CodeHeap 'non-profiled nmethods'
entryCount int
2926
fullCount int
0
methodCount int
2926
reservedTopAddress ulong: address
4733009920
startAddress ulong: address
4610097152
startTime long: millis
40031138500
unallocatedCapacity ulong: bytes
117868928

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
4771921920
startAddress ulong: address
4520263680
startTime long: millis
58734928042
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
60345400708
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
40031140833

JVM: Code Sweeper

SweepCodeCache

default profiling startTime duration eventThread 11 17 until JDK 20

Category: Java Virtual Machine / Code Sweeper

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

Configuration enabled threshold
default true 100 ms
profiling true 100 ms

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

CodeSweeperStatistics

default profiling startTime everychunk 11 17 until JDK 20

Category: Java Virtual Machine / Code Sweeper

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

Configuration enabled period
default true everyChunk
profiling true everyChunk

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

CodeSweeperConfiguration

default profiling startTime endchunk 11 17 until JDK 20

Category: Java Virtual Machine / Code Sweeper

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

Configuration enabled period
default true beginChunk
profiling true beginChunk

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

JVM: Compiler

Compilation

default profiling startTime duration eventThread 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 threshold
default true 1000 ms
profiling true 100 ms

Field Type Description
method Method Java Method
compileId uint Compilation Identifier
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
1152
compileId uint
15911
compileLevel ushort
4
inlinedBytes ulong: bytes
765
isOsr boolean
false
method Method
descriptor string
(Ljava/lang/Object;)Ljava/lang/Object;
hidden boolean
false
modifiers int
17
name string
$plus$colon
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
hidden boolean
false
modifiers int
1057
name string
scala/collection/AbstractSeq
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
startTime long: millis
45946380250
succeded boolean
true
codeSize ulong: bytes
51704
compileId uint
30764
compileLevel ushort
3
inlinedBytes ulong: bytes
1239
isOsr boolean
false
method Method
descriptor string
(Ljava/nio/ByteBuffer;)I
hidden boolean
false
modifiers int
1
name string
read
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
32
name string
sun/nio/ch/SocketChannelImpl
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
sun/nio/ch
startTime long: millis
78400531500
succeded boolean
true
codeSize ulong: bytes
1272
compileId uint
14523
compileLevel ushort
4
inlinedBytes ulong: bytes
1
isOsr boolean
false
method Method
descriptor string
(Lio/netty/handler/codec/http2/DefaultHttp2Connection;ILio/netty/handler/codec/http2/Http2Stream$State;)V
hidden boolean
false
modifiers int
0
name string
<init>
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
hidden boolean
false
modifiers int
32
name string
io/netty/handler/codec/http2/DefaultHttp2Connection$DefaultStream
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
io/netty/handler/codec/http2
startTime long: millis
30006388584
succeded boolean
true

CompilerPhase

default profiling startTime duration eventThread 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 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 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
default false
profiling true

Field Type Description
failureMessage string Failure Message
compileId uint Compilation Identifier

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

CompilerInlining

startTime eventThread 11 17 21 22 23

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 Byte Code Index

Examples 3
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 uint
1455
message string
callee is too large
startTime long: millis
414664792
succeeded boolean
false
bci int
3
callee CalleeMethod
descriptor string
(Ljava/lang/AbstractStringBuilder;Ljava/lang/Void;)V
name string
<init>
type string
java/lang/String
caller Method
descriptor string
(Ljava/lang/StringBuilder;)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
49
name string
java/lang/String
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/lang
compileId uint
1421
message string
callee is too large
startTime long: millis
360803125
succeeded boolean
false
bci int
94
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 uint
1486
message string
callee uses too much stack
startTime long: millis
670225042
succeeded boolean
false

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
nmetodsSize ulong: bytes until JDK 13 Compilation Resulting Size
nmetodCodeSize ulong: bytes until JDK 13 Compilation Resulting Code Size
peakTimeSpent long: millis Peak Time
totalTimeSpent long: millis Total time

Examples 3
bailoutCount int
3
compileCount int
34137
invalidatedCount int
0
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
bailoutCount int
3
compileCount int
17748
invalidatedCount int
0
osrBytesCompiled ulong: bytes
0
osrCompileCount int
174
peakTimeSpent long: millis
953
standardBytesCompiled ulong: bytes
0
standardCompileCount int
17574
startTime long: millis
59114432250
totalTimeSpent long: millis
44221
bailoutCount int
5
compileCount int
35172
invalidatedCount int
0
osrBytesCompiled ulong: bytes
0
osrCompileCount int
243
peakTimeSpent long: millis
1167
standardBytesCompiled ulong: bytes
0
standardCompileCount int
34929
startTime long: millis
77328678334
totalTimeSpent long: millis
104169

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

Examples 3
startTime long: millis
27602494875
threadCount int
4
tieredCompilation boolean
true
startTime long: millis
15845292917
threadCount int
4
tieredCompilation boolean
true
startTime long: millis
423294458
threadCount int
4
tieredCompilation boolean
true

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
DeoptimizeObjectsALotThreadCountAll
origin FlagValueOrigin
Default
startTime long: millis
27602499834
value int
1
name string
UnguardOnExecutionViolation
origin FlagValueOrigin
Default
startTime long: millis
30519912292
value int
0
name string
JavaPriority9_To_OSPriority
origin FlagValueOrigin
Default
startTime long: millis
30586822667
value int
-1

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
60345414125
value uint
111
name string
ParallelGCThreads
origin FlagValueOrigin
Default
startTime long: millis
52082156083
value uint
0
name string
UseSVE
origin FlagValueOrigin
Default
startTime long: millis
12863175584
value uint
0

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
TieredRateUpdateMaxTime
origin FlagValueOrigin
Default
startTime long: millis
676089084
value long
25
name string
ValueMapInitialSize
origin FlagValueOrigin
Default
startTime long: millis
364804875
value long
11
name string
MaxLabelRootDepth
origin FlagValueOrigin
Default
startTime long: millis
423471625
value long
1100

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
ProcessDistributionStride
origin FlagValueOrigin
Default
startTime long: millis
676107167
value ulong
4
name string
PreallocatedOutOfMemoryErrorCount
origin FlagValueOrigin
Default
startTime long: millis
364820250
value ulong
4
name string
GCTimeLimit
origin FlagValueOrigin
Default
startTime long: millis
423582750
value ulong
98

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
ZYoungCompactionLimit
origin FlagValueOrigin
Default
startTime long: millis
12863270167
value double
25.0
name string
CompileThresholdScaling
origin FlagValueOrigin
Default
startTime long: millis
423590875
value double
1.0
name string
CompileThresholdScaling
origin FlagValueOrigin
Default
startTime long: millis
15845388208
value double
1.0

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
TraceRangeCheckElimination
origin FlagValueOrigin
Default
startTime long: millis
676153709
value boolean
false
name string
C1UpdateMethodData
origin FlagValueOrigin
Default
startTime long: millis
423601333
value boolean
true
name string
BailoutOnExceptionHandlers
origin FlagValueOrigin
Default
startTime long: millis
364842458
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
PerfDataSaveFile
origin FlagValueOrigin
Default
startTime long: millis
30519988125
value string
null
name string
StartFlightRecording
origin FlagValueOrigin
Command line
startTime long: millis
676243792
value string
filename=[...]/code/experiments/jfreventcollector/jfr/sample_UseG1GC.jfr,settings=[...]/code/experiments/jfreventcollector/.cache/jfc.jfc
name string
DeoptimizeOnlyAt
origin FlagValueOrigin
Default
startTime long: millis
17899930458
value string

JVM: GC: Collector

GarbageCollection

default profiling startTime duration 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
26
longestPause Tickspan
216155667
name GCName
ParallelScavenge
startTime long: millis
16764354208
sumOfPauses Tickspan
216155667
cause GCCause
G1 Evacuation Pause
gcId uint
85
longestPause Tickspan
1736708
name GCName
G1New
startTime long: millis
29722323917
sumOfPauses Tickspan
1736708
cause GCCause
Allocation Failure
gcId uint
96
longestPause Tickspan
81701416
name GCName
DefNew
startTime long: millis
16602380667
sumOfPauses Tickspan
81701416

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
30164385792
gcId uint
123
startTime long: millis
94096613875

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
47
startTime long: millis
28056702708
tenuringThreshold uint
12
gcId uint
85
startTime long: millis
29722323917
tenuringThreshold uint
15
gcId uint
50
startTime long: millis
5210542833
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
197
startTime long: millis
55946746584
gcId uint
65
startTime long: millis
45193051333
gcId uint
286
startTime long: millis
64096175375

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 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
31
startTime long: millis
8479159917
type G1YCType
Normal

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
2
gcTimeRatio uint
12
isExplicitGCConcurrent boolean
false
isExplicitGCDisabled boolean
false
oldCollector GCName
G1Old
parallelGCThreads uint
8
pauseTarget long: millis
-9223372036854775808
startTime long: millis
12824331625
usesDynamicGCThreads boolean
true
youngCollector GCName
G1New
concurrentGCThreads uint
0
gcTimeRatio uint
99
isExplicitGCConcurrent boolean
false
isExplicitGCDisabled boolean
false
oldCollector GCName
SerialOld
parallelGCThreads uint
0
pauseTarget long: millis
-9223372036854775808
startTime long: millis
15621221667
usesDynamicGCThreads boolean
true
youngCollector GCName
DefNew
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
75047469167
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
79064864500
initialTenuringThreshold ubyte
7
maxTenuringThreshold ubyte
15
startTime long: millis
16561208250
initialTenuringThreshold ubyte
7
maxTenuringThreshold ubyte
15
startTime long: millis
63145622084

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
39413198375
tlabRefillWasteLimit ulong: bytes
64
usesTLABs boolean
true
minTLABSize ulong: bytes
2048
startTime long: millis
75290927459
tlabRefillWasteLimit ulong: bytes
64
usesTLABs boolean
true
minTLABSize ulong: bytes
2048
startTime long: millis
88354587167
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
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
36156163917
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
52241834458
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
2575302656
minSize ulong: bytes
1363144
newRatio uint
2
startTime long: millis
27650273500
maxSize ulong: bytes
1431633920
minSize ulong: bytes
89456640
newRatio uint
2
startTime long: millis
30690535375
maxSize ulong: bytes
1431306240
minSize ulong: bytes
89128960
newRatio uint
2
startTime long: millis
93887425708

JVM: GC: Detailed

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
37
gcTime long: millis
17
pauseTarget long: millis
200
startTime long: millis
9321049792
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
23
allocationRegionsUsedAfter ulong: bytes
47185920
allocationRegionsUsedBefore ulong: bytes
0
bytesCopied ulong: bytes
47185920
cSetRegions uint
188
cSetUsedAfter ulong: bytes
0
cSetUsedBefore ulong: bytes
394264576
gcId uint
45
regionsFreed uint
188
startTime long: millis
13220241625

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
1212484
gcId uint
29
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
[B
package Package
null
startTime long: millis
7918533000
totalSize ulong: bytes
33427832
count long
214383
gcId uint
28
objectClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
hidden boolean
false
modifiers int
49
name string
akka/actor/ChildActorPath
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
akka/actor
startTime long: millis
17449627375
totalSize ulong: bytes
6860256
count long
1467
gcId uint
0
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
49
name string
jdk/jfr/internal/AnnotationConstruct
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
startTime long: millis
372286000
totalSize ulong: bytes
35208

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
33106718959
statistics G1EvacuationStatistics
allocated ulong: bytes
457200
directAllocated ulong: bytes
0
failureUsed ulong: bytes
0
failureWaste ulong: bytes
0
gcId uint
94
regionEndWaste ulong: bytes
0
regionsRefilled uint: bytes
1
undoWaste ulong: bytes
0
used ulong: bytes
370928
wasted ulong: bytes
1016

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
25081289000
statistics G1EvacuationStatistics
allocated ulong: bytes
0
directAllocated ulong: bytes
0
failureUsed ulong: bytes
0
failureWaste ulong: bytes
0
gcId uint
79
regionEndWaste ulong: bytes
0
regionsRefilled uint: bytes
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 initial mark to the first mixed GC

Examples 1
currentOccupancy ulong: bytes
13159536
gcId uint
8
lastMarkingDuration long: millis
0
recentAllocationRate double: bytes-per-second
0.0
recentMutatorAllocationSize ulong: bytes
0
recentMutatorDuration long: millis
104
startTime long: millis
1553237875
targetOccupancy ulong: bytes
44040192
threshold ulong: bytes
19818086
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 initial mark to the first mixed GC
predictionActive boolean Prediction Active Indicates whether the adaptive IHOP prediction is active

Examples 1
additionalBufferSize ulong: bytes
348127232
currentOccupancy ulong: bytes
100050408
gcId uint
25
ihopTargetOccupancy ulong: bytes
551865548
predictedAllocationRate double: bytes-per-second
1.1766365773163897E8
predictedMarkingDuration long: millis
314
predictionActive boolean
false
startTime long: millis
6747742667
threshold ulong: bytes
261409996
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 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
gcId uint
3
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/util/jar/Attributes
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/util/jar
objectSize ulong: bytes
16
plabSize ulong: bytes
12032
startTime long: millis
940168334
tenured boolean
true
tenuringAge uint
1
gcId uint
5
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
49
name string
java/lang/String
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/lang
objectSize ulong: bytes
24
plabSize ulong: bytes
8176
startTime long: millis
1163392792
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 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
gcId uint
9
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
objectSize ulong: bytes
8208
startTime long: millis
1607661584
tenured boolean
true
tenuringAge uint
2
gcId uint
0
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
103152
startTime long: millis
424555667
tenured boolean
false
tenuringAge uint
0

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

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
88
size ulong: bytes
2048
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
11
lineNumber int
248
method Method
descriptor string
(Ljava/lang/Object;)Lscala/Option;
hidden boolean
false
modifiers int
1
name string
get
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
hidden boolean
false
modifiers int
49
name string
scala/collection/immutable/Map$Map1
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
scala/collection/immutable
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
30825556542
gcId uint
67
size ulong: bytes
16
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
20
lineNumber int
223
method Method
descriptor string
(Ljava/lang/Class;Lscala/collection/Seq;)Ljava/lang/reflect/Constructor;
hidden boolean
false
modifiers int
2
name string
matchingConstructor
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
hidden boolean
false
modifiers int
33
name string
io/reactors/Platform$Reflect$
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
io/reactors
type FrameType
Inlined
truncated boolean
false
startTime long: millis
49340528000
gcId uint
5
size ulong: bytes
24
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
198
lineNumber int
403
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
1168872542

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
13
gcId uint
17
size ulong: bytes
0
startTime long: millis
1795047833
age uint
6
gcId uint
2
size ulong: bytes
0
startTime long: millis
914806750

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
67
start ulong: address
30205280256
startTime long: millis
1433297167
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
869
gcId uint
3
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
48
name string
java/lang/invoke/MemberName
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/lang/invoke
startTime long: millis
976302875
totalSize ulong: bytes
41712
count long
1822
gcId uint
69
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
21.0.1
name string
java/util
startTime long: millis
8663866792
totalSize ulong: bytes
2320200
count long
532169
gcId uint
34
objectClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
hidden boolean
false
modifiers int
49
name string
akka/dispatch/Envelope
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
akka/dispatch
startTime long: millis
8979422834
totalSize ulong: bytes
12772056

G1HeapRegionInformation

startTime duration everychunk 11 17 21 22 23

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
index uint
42
start ulong: address
30152851456
startTime long: millis
12822303959
type G1HeapRegionType
Old
used ulong: bytes
2097136

ZPageAllocation

experimental default profiling startTime duration eventThread 11 17 21 22 23

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
11216002541

ZThreadPhase

experimental default profiling startTime duration eventThread 11 17 21 22 23

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
3
name string
Concurrent Roots JavaThreads
startTime long: millis
1170869500

ZStatisticsCounter

experimental default profiling startTime duration eventThread 11 17 21 22 23

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 10 ms
profiling true 10 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
1151208041
value ulong
13

ZStatisticsSampler

experimental default profiling startTime duration eventThread 11 17 21 22 23

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 10 ms
profiling true 10 ms

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

Examples 1
id ZStatisticsSamplerType
Concurrent Roots JavaThreads
startTime long: millis
745216500
value ulong
121708

JVM: GC: Heap

GCHeapSummary

default profiling startTime 11 17 21 22 23

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
17
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
95291016
startTime long: millis
1795049125
when GCWhen
After GC
gcId uint
2
heapSpace VirtualSpace
committedEnd ulong: address
30322196480
committedSize ulong: bytes
257425408
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
4294967296
start ulong: address
30064771072
heapUsed ulong: bytes
32714080
startTime long: millis
967623375
when GCWhen
Before GC
gcId uint
23
heapSpace VirtualSpace
committedEnd ulong: address
30691819520
committedSize ulong: bytes
627048448
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
4294967296
start ulong: address
30064771072
heapUsed ulong: bytes
392781104
startTime long: millis
5929721625
when GCWhen
Before GC

MetaspaceSummary

default profiling startTime 11 17 21 22 23

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
3080192
reserved ulong: bytes
1073741824
used ulong: bytes
2830240
dataSpace MetaspaceSizes
committed ulong: bytes
23396352
reserved ulong: bytes
67108864
used ulong: bytes
23220816
gcId uint
28
gcThreshold ulong: bytes
42729472
metaspace MetaspaceSizes
committed ulong: bytes
26476544
reserved ulong: bytes
1140850688
used ulong: bytes
26051056
startTime long: millis
7657987042
when GCWhen
After GC
classSpace MetaspaceSizes
committed ulong: bytes
2490368
reserved ulong: bytes
1073741824
used ulong: bytes
2421352
dataSpace MetaspaceSizes
committed ulong: bytes
20512768
reserved ulong: bytes
67108864
used ulong: bytes
20385384
gcId uint
7
gcThreshold ulong: bytes
36700160
metaspace MetaspaceSizes
committed ulong: bytes
23003136
reserved ulong: bytes
1140850688
used ulong: bytes
22806736
startTime long: millis
1228280542
when GCWhen
Before GC
classSpace MetaspaceSizes
committed ulong: bytes
2359296
reserved ulong: bytes
1073741824
used ulong: bytes
2291744
dataSpace MetaspaceSizes
committed ulong: bytes
19660800
reserved ulong: bytes
67108864
used ulong: bytes
19568280
gcId uint
2
gcThreshold ulong: bytes
22020096
metaspace MetaspaceSizes
committed ulong: bytes
22020096
reserved ulong: bytes
1140850688
used ulong: bytes
21860024
startTime long: millis
967624083
when GCWhen
Before GC

PSHeapSummary

default profiling startTime 11 17 21 22 23

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
edenSpace ObjectSpace
end ulong: address
34228142080
size ulong: bytes
1299709952
start ulong: address
32928432128
used ulong: bytes
1299709952
fromSpace ObjectSpace
end ulong: address
34264842240
size ulong: bytes
36700160
start ulong: address
34228142080
used ulong: bytes
30365680
gcId uint
23
oldObjectSpace ObjectSpace
end ulong: address
30407131136
size ulong: bytes
342360064
start ulong: address
30064771072
used ulong: bytes
178910352
oldSpace VirtualSpace
committedEnd ulong: address
30407131136
committedSize ulong: bytes
342360064
reservedEnd ulong: address
32928432128
reservedSize ulong: bytes
2863661056
start ulong: address
30064771072
startTime long: millis
10970344333
toSpace ObjectSpace
end ulong: address
34359738368
size ulong: bytes
77594624
start ulong: address
34282143744
used ulong: bytes
0
when GCWhen
Before GC
youngSpace VirtualSpace
committedEnd ulong: address
34359738368
committedSize ulong: bytes
1431306240
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
1431306240
start ulong: address
32928432128

G1HeapSummary

default profiling startTime 11 17 21 22 23

Category: Java Virtual Machine / GC / Heap

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

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

Configuration enabled
default true
profiling true

Field Type Description
gcId uint GC Identifier
when GCWhen When Consider contributing a description to jfreventcollector.
edenUsedSize ulong: bytes Eden Used Size
edenTotalSize ulong: bytes Eden Total Size
survivorUsedSize ulong: bytes Survivor Used Size
numberOfRegions uint Number of Regions

Examples 1
edenTotalSize ulong: bytes
343415664
edenUsedSize ulong: bytes
0
gcId uint
22
numberOfRegions uint
299
startTime long: millis
2838082750
survivorUsedSize ulong: bytes
31974544
when GCWhen
After GC

JVM: GC: Metaspace

MetaspaceGCThreshold

default profiling startTime 11 17 21 22 23

Category: Java Virtual Machine / GC / Metaspace

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

Configuration enabled
default true
profiling true

Field Type Description
oldValue ulong: bytes Old Value
newValue ulong: bytes New Value
updater GCThresholdUpdater Updater Consider contributing a description to jfreventcollector.

Examples 3
newValue ulong: bytes
42729472
oldValue ulong: bytes
38469632
startTime long: millis
6122275834
updater GCThresholdUpdater
compute_new_size
newValue ulong: bytes
141819904
oldValue ulong: bytes
141361152
startTime long: millis
67821273292
updater GCThresholdUpdater
compute_new_size
newValue ulong: bytes
244776960
oldValue ulong: bytes
195887104
startTime long: millis
78184037583
updater GCThresholdUpdater
compute_new_size

MetaspaceAllocationFailure

default profiling startTime stackTrace 11 17 21 22 23

Category: Java Virtual Machine / GC / Metaspace

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

Configuration enabled stackTrace
default true true
profiling true true

Field Type Description
classLoader ClassLoader Class Loader Consider contributing a description to jfreventcollector.
unsafeAnonymousClassLoader boolean until JDK 15 Unsafe Anonymous Class Loader
size ulong: bytes Size
metadataType MetadataType Metadata Type Consider contributing a description to jfreventcollector.
metaspaceObjectType MetaspaceObjectType Metaspace Object Type Consider contributing a description to jfreventcollector.

Examples 3
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
metadataType MetadataType
Metadata
metaspaceObjectType MetaspaceObjectType
ConstMethod
size ulong: bytes
104
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/ClassLoader;Ljava/lang/String;[BIILjava/security/ProtectionDomain;Ljava/lang/String;)Ljava/lang/Class;
hidden boolean
false
modifiers int
264
name string
defineClass1
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1057
name string
java/lang/ClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
1430932917
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
metadataType MetadataType
Metadata
metaspaceObjectType MetaspaceObjectType
ConstantPool
size ulong: bytes
2440
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/ClassLoader;Ljava/lang/String;[BIILjava/security/ProtectionDomain;Ljava/lang/String;)Ljava/lang/Class;
hidden boolean
false
modifiers int
264
name string
defineClass1
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1057
name string
java/lang/ClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type