Introduction

The following are the events for the OpenJDK 21 (jdk-21.0.2+0, 27-November-2023). The events are collected from the event configuration and the source code. Visit jfreventcollector for more information. this is also the place you can contribute additional event descriptions, if you don't want to contribute them directly to the OpenJDK. The site generator lives on GitHub too.

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

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

Category: Flight Recorder

Who requested the recording and why

Configuration enabled
default true
profiling true

Field Type Description
reason string Reason Reason for writing recording data to disk
recordingId int Recording Id Id of the recording that triggered the dump, or -1 if it was not related to a recording

DataLoss

default profiling startTime 11 17 21 22

Category: Flight Recorder

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

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
857
flushId ulong
44
size ulong: bytes
434690
startTime long: millis
51847140375
elements ulong
354
flushId ulong
52
size ulong: bytes
441913
startTime long: millis
56179944084
elements ulong
137
flushId ulong
70
size ulong: bytes
120975
startTime long: millis
76980740833

ActiveRecording

default profiling startTime duration stackTrace 11 17 21 22

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

Category: Flight Recorder

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

Configuration enabled
default true
profiling true

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

Examples 3
destination string
[...]/code/experiments/jfreventcollector/jfr/sample_UseParallelGC.jfr
disk boolean
true
flushInterval long: millis
1000
id long
1
maxAge long: millis
9223372036854775807
maxSize long: bytes
262144000
name string
1
recordingDuration long: millis
9223372036854775807
recordingStart long: epochmillis
1701099063735
stackTrace StackTrace
null
startTime long: millis
46912624834
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
1701099181498
stackTrace StackTrace
null
startTime long: millis
86681976541
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
1701098850537
stackTrace StackTrace
null
startTime long: millis
192132299750

ActiveSetting

default profiling startTime duration stackTrace 11 17 21 22

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

Category: Flight Recorder

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

Configuration enabled
default true
profiling true

Field Type Description
id long Event Id
name string Setting Name
value string Setting Value

Examples 3
id long
49
name string
threshold
stackTrace StackTrace
null
startTime long: millis
688133083
value string
0 ms
id long
12
name string
enabled
stackTrace StackTrace
null
startTime long: millis
339201541
value string
true
id long
11
name string
threshold
stackTrace StackTrace
null
startTime long: millis
479682042
value string
10 ms

JVM

JVMInformation

default profiling startTime duration end chunk 11 17 21 22

Category: Java Virtual Machine

Description of JVM and the Java application

Configuration enabled period
default true beginChunk
profiling true beginChunk

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

Examples 3
javaArguments string
[...]/code/experiments/jfreventcollector/.cache/renaissance.jar -t 5 -r 1 all
jvmArguments string
-XX:StartFlightRecording=filename=[...]/code/experiments/jfreventcollector/jfr/sample_UseG1GC.jfr,settings=[...]/code/experiments/jfreventcollector/.cache/jfc.jfc -XX:+UseG1GC
jvmFlags string
null
jvmName string
OpenJDK 64-Bit Server VM
jvmStartTime long: epochmillis
1701098849915
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
15986
startTime long: millis
135012505000
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
1701099181221
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
16877
startTime long: millis
48587905500
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
1701099063338
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
16596
startTime long: millis
20953202542

InitialSystemProperty

default profiling startTime end chunk 11 17 21 22

Category: Java Virtual Machine

System Property at JVM start

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
key string Key
value string Value

Examples 3
key string
java.vm.version
startTime long: millis
340530041
value string
21.0.1+12-LTS
key string
java.library.path
startTime long: millis
98899630834
value string
[...]/Library/Java/Extensions:/Library/Java/Extensions:/Network/Library/Java/Extensions:/System/Library/Java/Extensions:/usr/lib/java:.
key string
jdk.debug
startTime long: millis
75467363958
value string
release

JVM: Class Loading

ClassLoad

startTime duration eventThread stackTrace 11 17 21 22

Category: Java Virtual Machine / Class Loading

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

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

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

Examples 3
definingClassLoader ClassLoader
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/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
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/String;)Ljava/lang/Class;
hidden boolean
false
modifiers int
266
name string
findBootstrapClass
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
711856500
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/util/logging/StreamHandler
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
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/String;)Ljava/lang/Class;
hidden boolean
false
modifiers int
266
name string
findBootstrapClass
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
508537167
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$AppClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
jdk/internal/loader
hidden boolean
false
modifiers int
49
name string
org/renaissance/core/Logging
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
app
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
32
name string
jdk/internal/loader/ClassLoaders$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
2
lineNumber int
21
method Method
descriptor string
()V
hidden boolean
false
modifiers int
8
name string
<clinit>
type Class
classLoader ClassLoader
name string
app
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
32
name string
jdk/internal/loader/ClassLoaders$AppClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
jdk/internal/loader
hidden boolean
false
modifiers int
49
name string
org/renaissance/core/Launcher
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
app
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
32
name string
jdk/internal/loader/ClassLoaders$AppClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
jdk/internal/loader
location string
null
name string
null
version string
null
name string
org/renaissance/core
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
360709750

ClassDefine

startTime eventThread stackTrace 11 17 21 22

Category: Java Virtual Machine / Class Loading

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

Configuration enabled stackTrace
default false true
profiling false true

Field Type Description
definedClass Class Defined Class Consider contributing a description to jfreventcollector.
definingClassLoader ClassLoader Defining Class Loader Consider contributing a description to jfreventcollector.

Examples 3
definedClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
32
name string
java/util/Formatter$Flags
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/util
definingClassLoader ClassLoader
name string
bootstrap
type Class
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
4
lineNumber int
2924
method Method
descriptor string
(Ljava/lang/String;II)V
hidden boolean
false
modifiers int
2
name string
flags
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
32
name string
java/util/Formatter$FormatSpecifier
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
515391250
definedClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
48
name string
java/util/regex/Pattern$Branch
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/util/regex
definingClassLoader ClassLoader
name string
bootstrap
type Class
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
812
lineNumber int
3259
method Method
descriptor string
()Ljava/util/regex/Pattern$Node;
hidden boolean
false
modifiers int
2
name string
group0
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
49
name string
java/util/regex/Pattern
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/util/regex
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
363969750
definedClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1537
name string
sun/util/locale/provider/AvailableLanguageTags
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
sun/util/locale/provider
definingClassLoader ClassLoader
name string
bootstrap
type Class
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
221
method Method
descriptor string
()Ljava/text/spi/DecimalFormatSymbolsProvider;
hidden boolean
false
modifiers int
4098
name string
lambda$getDecimalFormatSymbolsProvider$4
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
sun/util/locale/provider/JRELocaleProviderAdapter
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
sun/util/locale/provider
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
721852041

ClassRedefinition

default profiling startTime 15 17 21 22

Category: Java Virtual Machine / Class Loading

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

Configuration enabled
default 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

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

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

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
4057416625
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/immutable/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/immutable
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
startTime long: millis
8802329625
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/immutable/IndexedSeqOps
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
scala/collection/immutable
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
startTime long: millis
5904962459
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+0x0000000800376000/283923004
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

Category: Java Virtual Machine / Code Cache

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

Configuration enabled
default true
profiling true

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

CodeCacheStatistics

default profiling startTime every chunk 11 17 21 22

Category: Java Virtual Machine / Code Cache

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

Configuration enabled period
default true everyChunk
profiling true everyChunk

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

Examples 3
adaptorCount int
0
codeBlobType CodeBlobType
CodeHeap 'non-profiled nmethods'
entryCount int
3144
fullCount int
0
methodCount int
3144
reservedTopAddress ulong: address
4778721280
startAddress ulong: address
4655808512
startTime long: millis
38504740458
unallocatedCapacity ulong: bytes
117436032
adaptorCount int
486
codeBlobType CodeBlobType
CodeHeap 'non-nmethods'
entryCount int
576
fullCount int
0
methodCount int
0
reservedTopAddress ulong: address
4652564480
startAddress ulong: address
4646715392
startTime long: millis
46408567292
unallocatedCapacity ulong: bytes
4466816
adaptorCount int
0
codeBlobType CodeBlobType
CodeHeap 'non-profiled nmethods'
entryCount int
3088
fullCount int
0
methodCount int
3088
reservedTopAddress ulong: address
5486149632
startAddress ulong: address
5363236864
startTime long: millis
117193288625
unallocatedCapacity ulong: bytes
116988416

CodeCacheConfiguration

default profiling startTime end chunk 11 17 21 22

Category: Java Virtual Machine / Code Cache

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

Configuration enabled period
default true beginChunk
profiling true beginChunk

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

Examples 3
expansionSize ulong: bytes
65536
initialSize ulong: bytes
2555904
minBlockLength ulong: bytes
6
nonNMethodSize ulong: bytes
5839564
nonProfiledSize ulong: bytes
122909338
profiledSize ulong: bytes
122909338
reservedSize ulong: bytes
251658240
reservedTopAddress ulong: address
5486149632
startAddress ulong: address
5234491392
startTime long: millis
75476045500
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
4775477248
startAddress ulong: address
4523819008
startTime long: millis
46914774292
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
4778721280
startAddress ulong: address
4527063040
startTime long: millis
48589449083

JVM: Compiler

JITRestart

default profiling startTime eventThread 17 21 22

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

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
7040
compileId int
14402
compileLevel ushort
3
compiler CompilerType
c1
inlinedBytes ulong: bytes
123
isOsr boolean
false
method Method
descriptor string
(Lcom/twitter/finagle/http/Request;Lcom/twitter/finagle/Service;)Lcom/twitter/util/Future;
hidden boolean
false
modifiers int
1
name string
apply
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
hidden boolean
false
modifiers int
49
name string
com/twitter/finagle/http/filter/HttpNackFilter
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/http/filter
startTime long: millis
52637788584
succeded boolean
true
codeSize ulong: bytes
4728
compileId int
4965
compileLevel ushort
4
compiler CompilerType
c2
inlinedBytes ulong: bytes
0
isOsr boolean
false
method Method
descriptor string
()I
hidden boolean
false
modifiers int
0
name string
readLine
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
32
name string
java/util/Properties$LineReader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/util
startTime long: millis
5978525083
succeded boolean
true
codeSize ulong: bytes
38768
compileId int
8071
compileLevel ushort
4
compiler CompilerType
c2
inlinedBytes ulong: bytes
6045
isOsr boolean
false
method Method
descriptor string
(Lcafesat/asts/core/Trees$Formula;Lscala/collection/mutable/ListBuffer;Lscala/runtime/ObjectRef;Lscala/runtime/LazyRef;)I
hidden boolean
false
modifiers int
18
name string
rec$1
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
hidden boolean
false
modifiers int
49
name string
cafesat/sat/ConjunctiveNormalForm$
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
cafesat/sat
startTime long: millis
78091594041
succeded boolean
true

CompilerPhase

default profiling startTime duration eventThread 11 17 21 22

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

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
6317
failureMessage string
out of virtual registers in LIR generator
startTime long: millis
29774204541
compileId int
23506
failureMessage string
concurrent class loading
startTime long: millis
98563910709
compileId int
5061
failureMessage string
concurrent class loading
startTime long: millis
5977357375

CompilerInlining

startTime eventThread 11 17 21 22

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
47
callee CalleeMethod
descriptor string
()B
name string
coder
type string
java/lang/String
caller Method
descriptor string
(Ljava/lang/String;I)Z
hidden boolean
false
modifiers int
1
name string
startsWith
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 int
1485
message string
inline
startTime long: millis
479413459
succeeded boolean
true
bci int
1
callee CalleeMethod
descriptor string
()V
name string
<init>
type string
java/lang/Object
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/AbstractCollection
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
1449
message string
inline
startTime long: millis
687632500
succeeded boolean
true
bci int
1
callee CalleeMethod
descriptor string
()V
name string
<init>
type string
java/lang/Object
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/AbstractCollection
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
1466
message string
inline
startTime long: millis
339052458
succeeded boolean
true

Deoptimization

default profiling startTime eventThread stackTrace 14 17 21 22

Category: Java Virtual Machine / Compiler

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

Configuration enabled stackTrace
default true false
profiling true true

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

Examples 3
action DeoptimizationAction
maybe_recompile
bci int
51
compileId int
2538
compiler CompilerType
c2
instruction Bytecode
invokevirtual
lineNumber int
1380
method Method
descriptor string
(Ljava/lang/Class;I)Ljava/lang/Object;
hidden boolean
false
modifiers int
1
name string
allocateUninitializedArray
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
49
name string
jdk/internal/misc/Unsafe
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/misc
reason DeoptimizationReason
class_check
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
51
lineNumber int
1380
method Method
descriptor string
(Ljava/lang/Class;I)Ljava/lang/Object;
hidden boolean
false
modifiers int
1
name string
allocateUninitializedArray
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
49
name string
jdk/internal/misc/Unsafe
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/misc
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
1032675792
action DeoptimizationAction
reinterpret
bci int
4
compileId int
1465
compiler CompilerType
c2
instruction Bytecode
ifne
lineNumber int
78
method Method
descriptor string
(I)Ljava/lang/CharacterData;
hidden boolean
false
modifiers int
24
name string
of
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1056
name string
java/lang/CharacterData
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
reason DeoptimizationReason
unstable_if
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
4
lineNumber int
78
method Method
descriptor string
(I)Ljava/lang/CharacterData;
hidden boolean
false
modifiers int
24
name string
of
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1056
name string
java/lang/CharacterData
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
JIT compiled
truncated boolean
false
startTime long: millis
377122833
action DeoptimizationAction
maybe_recompile
bci int
19
compileId int
3436
compiler CompilerType
c2
instruction Bytecode
if_icmpge
lineNumber int
285
method Method
descriptor string
(Ljava/nio/ByteBuffer;ILjava/lang/String;I)I
hidden boolean
false
modifiers int
8
name string
stringFromByteBufferMatches
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
jdk/internal/jimage/ImageStringsReader
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/jimage
reason DeoptimizationReason
profile_predicate
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
19
lineNumber int
285
method Method
descriptor string
(Ljava/nio/ByteBuffer;ILjava/lang/String;I)I
hidden boolean
false
modifiers int
8
name string
stringFromByteBufferMatches
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
jdk/internal/jimage/ImageStringsReader
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/jimage
type FrameType
Inlined
truncated boolean
false
startTime long: millis
4128942541

CompilerStatistics

default profiling startTime every chunk 11 17 21 22

Category: Java Virtual Machine / Compiler

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

Configuration enabled period
default true 1000 ms
profiling true 1000 ms

Field Type Description
compileCount int Compiled Methods
bailoutCount int Bailouts
invalidatedCount int Invalidated Compilations
osrCompileCount int OSR Compilations
standardCompileCount int Standard Compilations
osrBytesCompiled ulong: bytes OSR Bytes Compiled
standardBytesCompiled ulong: bytes Standard Bytes Compiled
nmethodsSize ulong: bytes Compilation Resulting Size
nmethodCodeSize ulong: bytes Compilation Resulting Code Size
peakTimeSpent long: millis Peak Time
totalTimeSpent long: millis Total time

Examples 3
bailoutCount int
4
compileCount int
8034
invalidatedCount int
0
nmethodCodeSize ulong: bytes
10128120
nmethodsSize ulong: bytes
15424704
osrBytesCompiled ulong: bytes
0
osrCompileCount int
89
peakTimeSpent long: millis
4774
standardBytesCompiled ulong: bytes
0
standardCompileCount int
7945
startTime long: millis
83761774208
totalTimeSpent long: millis
54299
bailoutCount int
6
compileCount int
23625
invalidatedCount int
0
nmethodCodeSize ulong: bytes
30925584
nmethodsSize ulong: bytes
47172856
osrBytesCompiled ulong: bytes
0
osrCompileCount int
181
peakTimeSpent long: millis
1068
standardBytesCompiled ulong: bytes
0
standardCompileCount int
23444
startTime long: millis
82109837625
totalTimeSpent long: millis
51632
bailoutCount int
2
compileCount int
7782
invalidatedCount int
0
nmethodCodeSize ulong: bytes
9358800
nmethodsSize ulong: bytes
14780720
osrBytesCompiled ulong: bytes
0
osrCompileCount int
66
peakTimeSpent long: millis
1043
standardBytesCompiled ulong: bytes
0
standardCompileCount int
7716
startTime long: millis
32415498042
totalTimeSpent long: millis
20578

CompilerConfiguration

default profiling startTime end chunk 11 17 21 22

Category: Java Virtual Machine / Compiler

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

Configuration enabled period
default true beginChunk
profiling true beginChunk

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

Examples 3
dynamicCompilerThreadCount boolean
true
startTime long: millis
14190149791
threadCount int
4
tieredCompilation boolean
true
dynamicCompilerThreadCount boolean
true
startTime long: millis
20956119292
threadCount int
4
tieredCompilation boolean
true
dynamicCompilerThreadCount boolean
true
startTime long: millis
117193287416
threadCount int
4
tieredCompilation boolean
true

JVM: Diagnostics

SyncOnValueBasedClass

experimental default profiling startTime eventThread stackTrace 16 17 21 22

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

Category: Java Virtual Machine / Diagnostics

Information about a successfully written Java heap dump

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

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

JavaAgent

default profiling startTime end chunk 21 22

Category: Java Virtual Machine / Diagnostics

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

Configuration enabled period
default true endChunk
profiling true endChunk

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

NativeAgent

default profiling startTime end chunk 21 22

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

Category: Java Virtual Machine / Flag

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

Configuration enabled
default true
profiling true

Field Type Description
name string Name
oldValue int Old Value
newValue int New Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

UnsignedIntFlagChanged

default profiling startTime 11 17 21 22

Category: Java Virtual Machine / Flag

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

Configuration enabled
default true
profiling true

Field Type Description
name string Name
oldValue uint Old Value
newValue uint New Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

LongFlagChanged

default profiling startTime 11 17 21 22

Category: Java Virtual Machine / Flag

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

Configuration enabled
default true
profiling true

Field Type Description
name string Name
oldValue long Old Value
newValue long New Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

UnsignedLongFlagChanged

default profiling startTime 11 17 21 22

Category: Java Virtual Machine / Flag

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

Configuration enabled
default true
profiling true

Field Type Description
name string Name
oldValue ulong Old Value
newValue ulong New Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

DoubleFlagChanged

default profiling startTime 11 17 21 22

Category: Java Virtual Machine / Flag

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

Configuration enabled
default true
profiling true

Field Type Description
name string Name
oldValue double Old Value
newValue double New Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

BooleanFlagChanged

default profiling startTime 11 17 21 22

Category: Java Virtual Machine / Flag

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

Configuration enabled
default true
profiling true

Field Type Description
name string Name
oldValue boolean Old Value
newValue boolean New Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

StringFlagChanged

default profiling startTime 11 17 21 22

Category: Java Virtual Machine / Flag

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

Configuration enabled
default true
profiling true

Field Type Description
name string Name
oldValue string Old Value
newValue string New Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

IntFlag

default profiling startTime duration end chunk 11 17 21 22

Category: Java Virtual Machine / Flag

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

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value int Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

Examples 3
name string
JavaPriority2_To_OSPriority
origin FlagValueOrigin
Default
startTime long: millis
46914777209
value int
-1
name string
ThreadPriorityPolicy
origin FlagValueOrigin
Default
startTime long: millis
689924375
value int
0
name string
ObjectAlignmentInBytes
origin FlagValueOrigin
Default
startTime long: millis
28294044708
value int
8

UnsignedIntFlag

default profiling startTime duration end chunk 11 17 21 22

Category: Java Virtual Machine / Flag

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

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value uint Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

Examples 3
name string
MarkSweepAlwaysCompactCount
origin FlagValueOrigin
Default
startTime long: millis
101284454042
value uint
4
name string
G1RefProcDrainInterval
origin FlagValueOrigin
Default
startTime long: millis
135014006416
value uint
1000
name string
ConcGCThreads
origin FlagValueOrigin
Default
startTime long: millis
28294051291
value uint
0

LongFlag

default profiling startTime duration end chunk 11 17 21 22

Category: Java Virtual Machine / Flag

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

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value long Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

Examples 3
name string
LoopMaxUnroll
origin FlagValueOrigin
Default
startTime long: millis
340862500
value long
16
name string
InterpreterProfilePercentage
origin FlagValueOrigin
Default
startTime long: millis
689940958
value long
33
name string
TieredRateUpdateMaxTime
origin FlagValueOrigin
Default
startTime long: millis
482150334
value long
25

UnsignedLongFlag

default profiling startTime duration end chunk 11 17 21 22

Category: Java Virtual Machine / Flag

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

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value ulong Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

Examples 3
name string
LargePageHeapSizeThreshold
origin FlagValueOrigin
Default
startTime long: millis
482166750
value ulong
134217728
name string
MetadataAllocationFailALotInterval
origin FlagValueOrigin
Default
startTime long: millis
340879541
value ulong
1000
name string
TLABRefillWasteFraction
origin FlagValueOrigin
Default
startTime long: millis
689956208
value ulong
64

DoubleFlag

default profiling startTime duration end chunk 11 17 21 22

Category: Java Virtual Machine / Flag

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

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value double Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

Examples 3
name string
G1PeriodicGCSystemLoadThreshold
origin FlagValueOrigin
Default
startTime long: millis
82931781125
value double
0.0
name string
G1PeriodicGCSystemLoadThreshold
origin FlagValueOrigin
Default
startTime long: millis
101284488959
value double
0.0
name string
ZCollectionIntervalMajor
origin FlagValueOrigin
Default
startTime long: millis
43601228416
value double
-1.0

BooleanFlag

default profiling startTime duration end chunk 11 17 21 22

Category: Java Virtual Machine / Flag

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

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value boolean Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

Examples 3
name string
PatchALot
origin FlagValueOrigin
Default
startTime long: millis
340898583
value boolean
false
name string
UseFastNewObjectArray
origin FlagValueOrigin
Default
startTime long: millis
689971541
value boolean
true
name string
UseSIMDForBigIntegerShiftIntrinsics
origin FlagValueOrigin
Default
startTime long: millis
482184625
value boolean
true

StringFlag

default profiling startTime duration end chunk 11 17 21 22

Category: Java Virtual Machine / Flag

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

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value string Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

Examples 3
name string
DumpLoadedClassList
origin FlagValueOrigin
Default
startTime long: millis
14190249833
value string
null
name string
DumpLoadedClassList
origin FlagValueOrigin
Default
startTime long: millis
690006958
value string
null
name string
PrintIdealGraphAddress
origin FlagValueOrigin
Default
startTime long: millis
20956800084
value string
127.0.0.1

JVM: GC: Collector

GarbageCollection

default profiling startTime duration eventThread 11 17 21 22

Category: Java Virtual Machine / GC / Collector

Garbage collection performed by the JVM

Configuration enabled threshold
default true 0 ms
profiling true 0 ms

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

Examples 3
cause GCCause
G1 Evacuation Pause
gcId uint
12
longestPause Tickspan
4686625
name GCName
G1New
startTime long: millis
1416420791
sumOfPauses Tickspan
4686625
cause GCCause
Metadata GC Threshold
gcId uint
1
longestPause Tickspan
14376625
name GCName
SerialOld
startTime long: millis
693402041
sumOfPauses Tickspan
14376625
cause GCCause
Allocation Failure
gcId uint
37
longestPause Tickspan
221258375
name GCName
ParallelScavenge
startTime long: millis
30169596125
sumOfPauses Tickspan
221258375

SystemGC

default profiling startTime duration eventThread stackTrace 17 21 22

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
1054362208
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
89406320667
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
1753256291

ParallelOldGarbageCollection

default profiling startTime duration 11 17 21 22

Category: Java Virtual Machine / GC / Collector

Appearing in: ParallelGC

Missing in: G1GC, SerialGC, ShenandoahGC, ZGC

Extra information specific to Parallel Old Garbage Collections

Configuration enabled threshold
default true 0 ms
profiling true 0 ms

Field Type Description
gcId uint GC Identifier
densePrefix ulong: address Dense Prefix The address of the dense prefix, used when compacting

Examples 1
densePrefix ulong: address
30155997184
gcId uint
75
startTime long: millis
79123446292

YoungGarbageCollection

default profiling startTime duration 11 17 21 22

Category: Java Virtual Machine / GC / Collector

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

Extra information specific to Young Garbage Collections

Configuration enabled threshold
default true 0 ms
profiling true 0 ms

Field Type Description
gcId uint GC Identifier
tenuringThreshold uint Tenuring Threshold

Examples 3
gcId uint
105
startTime long: millis
97312798542
tenuringThreshold uint
15
gcId uint
71
startTime long: millis
7944134375
tenuringThreshold uint
1
gcId uint
3
startTime long: millis
930384000
tenuringThreshold uint
1

OldGarbageCollection

default profiling startTime duration 11 17 21 22

Category: Java Virtual Machine / GC / Collector

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

Extra information specific to Old Garbage Collections

Configuration enabled threshold
default true 0 ms
profiling true 0 ms

Field Type Description
gcId uint GC Identifier

Examples 3
gcId uint
9
startTime long: millis
1450494417
gcId uint
54
startTime long: millis
43628069916
gcId uint
1
startTime long: millis
693402041

G1GarbageCollection

default profiling startTime duration 11 17 21 22

Category: Java Virtual Machine / GC / Collector

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Extra information specific to G1 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
4
startTime long: millis
950666083
type G1YCType
Normal

ZYoungGarbageCollection

default profiling startTime duration eventThread 21 22

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

Category: Java Virtual Machine / GC / Collector

Extra information specific to ZGC Old Garbage Collections

Configuration enabled threshold
default true 0 ms
profiling true 0 ms

Field Type Description
gcId uint GC Identifier

JVM: GC: Configuration

GCConfiguration

default profiling startTime duration end chunk 11 17 21 22

Category: Java Virtual Machine / GC / Configuration

The configuration of the garbage collector

Configuration enabled period
default true everyChunk
profiling true everyChunk

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

Examples 3
concurrentGCThreads uint
0
gcTimeRatio uint
99
isExplicitGCConcurrent boolean
false
isExplicitGCDisabled boolean
false
oldCollector GCName
SerialOld
parallelGCThreads uint
0
pauseTarget long: millis
-9223372036854775808
startTime long: millis
100110830083
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
117267336166
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
99012180792
usesDynamicGCThreads boolean
true
youngCollector GCName
ParallelScavenge

GCSurvivorConfiguration

default profiling startTime duration end chunk 11 17 21 22

Category: Java Virtual Machine / GC / Configuration

The configuration of the survivors of garbage collection

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
maxTenuringThreshold ubyte Maximum Tenuring Threshold Upper limit for the age of how old objects to keep in the survivor area
initialTenuringThreshold ubyte Initial Tenuring Threshold Initial age limit for how old objects to keep in survivor area

Examples 3
initialTenuringThreshold ubyte
7
maxTenuringThreshold ubyte
15
startTime long: millis
117267337291
initialTenuringThreshold ubyte
7
maxTenuringThreshold ubyte
15
startTime long: millis
14613397750
initialTenuringThreshold ubyte
7
maxTenuringThreshold ubyte
15
startTime long: millis
108530487125

GCTLABConfiguration

default profiling startTime duration end chunk 11 17 21 22

Category: Java Virtual Machine / GC / Configuration

The configuration of the Thread Local Allocation Buffers (TLABs)

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
usesTLABs boolean TLABs Used If Thread Local Allocation Buffers (TLABs) are in use
minTLABSize ulong: bytes Minimum TLAB Size
tlabRefillWasteLimit ulong: bytes TLAB Refill Waste Limit

Examples 3
minTLABSize ulong: bytes
2048
startTime long: millis
108530488542
tlabRefillWasteLimit ulong: bytes
64
usesTLABs boolean
true
minTLABSize ulong: bytes
2048
startTime long: millis
698262208
tlabRefillWasteLimit ulong: bytes
64
usesTLABs boolean
true
minTLABSize ulong: bytes
2048
startTime long: millis
38672883750
tlabRefillWasteLimit ulong: bytes
64
usesTLABs boolean
true

GCHeapConfiguration

default profiling startTime duration end chunk 11 17 21 22

Category: Java Virtual Machine / GC / Configuration

The configuration of the garbage collected heap

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
minSize ulong: bytes Minimum Heap Size
maxSize ulong: bytes Maximum Heap Size
initialSize ulong: bytes Initial Heap Size
usesCompressedOops boolean If Compressed Oops Are Used If compressed Oops (Ordinary Object Pointers) are enabled
compressedOopsMode NarrowOopMode Compressed Oops Mode The kind of compressed oops being used
objectAlignment ulong: bytes Object Alignment Object alignment (in bytes) on the heap
heapAddressBits ubyte Heap Address Size Heap Address Size (in bits)

Examples 3
compressedOopsMode NarrowOopMode
Zero based
heapAddressBits ubyte
32
initialSize ulong: bytes
268435456
maxSize ulong: bytes
4294967296
minSize ulong: bytes
8388608
objectAlignment ulong: bytes
8
startTime long: millis
698263208
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
14613399166
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
496231084
usesCompressedOops boolean
true

YoungGenerationConfiguration

default profiling startTime duration end chunk 11 17 21 22

Category: Java Virtual Machine / GC / Configuration

The configuration of the young generation of the garbage collected heap

Configuration enabled period
default true beginChunk
profiling true beginChunk

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

Examples 3
maxSize ulong: bytes
2575302656
minSize ulong: bytes
1363144
newRatio uint
2
startTime long: millis
196524385083
maxSize ulong: bytes
1431633920
minSize ulong: bytes
89456640
newRatio uint
2
startTime long: millis
97864789666
maxSize ulong: bytes
1431306240
minSize ulong: bytes
89128960
newRatio uint
2
startTime long: millis
496238042

JVM: GC: Detailed

ZThreadDebug

internal startTime duration eventThread 18 21 22

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

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
82
gcTime long: millis
102
pauseTarget long: millis
200
startTime long: millis
63559704750
timeSlice long: millis
201

EvacuationInformation

default profiling startTime 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

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

Configuration enabled
default true
profiling true

Field Type Description
gcId uint GC Identifier
cSetRegions uint Collection Set Regions
cSetUsedBefore ulong: bytes Collection Set Before Memory usage before GC in the collection set regions
cSetUsedAfter ulong: bytes Collection Set After Memory usage after GC in the collection set regions
allocationRegions uint Allocation Regions Regions chosen as allocation regions during evacuation (includes survivors and old space regions)
allocationRegionsUsedBefore ulong: bytes Allocation Regions Before Memory usage before GC in allocation regions
allocationRegionsUsedAfter ulong: bytes Allocation Regions After Memory usage after GC in allocation regions
bytesCopied ulong: bytes Bytes Copied
regionsFreed uint Regions Freed

Examples 1
allocationRegions uint
22
allocationRegionsUsedAfter ulong: bytes
46137344
allocationRegionsUsedBefore ulong: bytes
1048576
bytesCopied ulong: bytes
45088768
cSetRegions uint
34
cSetUsedAfter ulong: bytes
0
cSetUsedBefore ulong: bytes
71303168
gcId uint
41
regionsFreed uint
34
startTime long: millis
29381136750

ObjectCountAfterGC

startTime 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

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

Configuration enabled
default false
profiling false

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

Examples 3
count long
96
gcId uint
1
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
[Ljava/util/concurrent/ConcurrentHashMap$Node;
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/util/concurrent
startTime long: millis
702041958
totalSize ulong: bytes
318272
count long
6731
gcId uint
17
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/util/LinkedHashMap
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/util
startTime long: millis
1617457750
totalSize ulong: bytes
430784
count long
292085
gcId uint
22
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
32
name string
java/util/HashMap$Node
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/util
startTime long: millis
13696186625
totalSize ulong: bytes
9346720

G1EvacuationYoungStatistics

default profiling startTime 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Memory related evacuation statistics during GC for the young generation

Configuration enabled
default true
profiling true

Field Type Description
statistics G1EvacuationStatistics struct Evacuation Statistics

Examples 1
startTime long: millis
36822423375
statistics G1EvacuationStatistics
allocated ulong: bytes
23068672
directAllocated ulong: bytes
0
failureUsed ulong: bytes
0
failureWaste ulong: bytes
0
gcId uint
49
numDirectAllocated ulong
5
numPlabsFilled ulong
2193956712555703988
regionEndWaste ulong: bytes
0
regionsRefilled uint
11
undoWaste ulong: bytes
0
used ulong: bytes
23067416
wasted ulong: bytes
1256

G1EvacuationOldStatistics

default profiling startTime 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Memory related evacuation statistics during GC for the old generation

Configuration enabled
default true
profiling true

Field Type Description
statistics G1EvacuationStatistics struct Evacuation Statistics

Examples 1
startTime long: millis
58319847791
statistics G1EvacuationStatistics
allocated ulong: bytes
58216008
directAllocated ulong: bytes
0
failureUsed ulong: bytes
0
failureWaste ulong: bytes
0
gcId uint
75
numDirectAllocated ulong
6184184024
numPlabsFilled ulong
0
regionEndWaste ulong: bytes
0
regionsRefilled uint
28
undoWaste ulong: bytes
0
used ulong: bytes
56031472
wasted ulong: bytes
2032

G1BasicIHOP

default profiling startTime 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Basic statistics related to current IHOP calculation

Configuration enabled
default true
profiling true

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

Examples 1
currentOccupancy ulong: bytes
369087968
gcId uint
46
lastMarkingDuration long: millis
4056
recentAllocationRate double: bytes-per-second
9.574403986410235E7
recentMutatorAllocationSize ulong: bytes
31844352
recentMutatorDuration long: millis
332
startTime long: millis
34612846666
targetOccupancy ulong: bytes
2006974464
threshold ulong: bytes
1647272299
thresholdPercentage float: percentage
0.8207739

G1AdaptiveIHOP

default profiling startTime 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Statistics related to current adaptive IHOP calculation

Configuration enabled
default true
profiling true

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

Examples 1
additionalBufferSize ulong: bytes
656408576
currentOccupancy ulong: bytes
187135592
gcId uint
114
ihopTargetOccupancy ulong: bytes
1039977676
predictedAllocationRate double: bytes-per-second
8.635352805272725E7
predictedMarkingDuration long: millis
775
predictionActive boolean
true
startTime long: millis
94160192958
threshold ulong: bytes
316619231
thresholdPercentage float: percentage
0.3044481

PromoteObjectInNewPLAB

profiling startTime eventThread 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC

Missing in: SerialGC, ShenandoahGC, ZGC

Object survived scavenge and was copied to a new Promotion Local Allocation Buffer (PLAB). Supported GCs are Parallel 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
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
32752
startTime long: millis
1224516459
tenured boolean
false
tenuringAge uint
1
gcId uint
7
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/util/LinkedHashMap
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/util
objectSize ulong: bytes
64
plabSize ulong: bytes
56672
startTime long: millis
1208536833
tenured boolean
false
tenuringAge uint
0

PromoteObjectOutsidePLAB

profiling startTime eventThread 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC

Missing in: SerialGC, ShenandoahGC, ZGC

Object survived scavenge and was copied directly to the heap. Supported GCs are Parallel 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
7
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
51824
startTime long: millis
1208438125
tenured boolean
false
tenuringAge uint
0
gcId uint
11
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
16672
startTime long: millis
2096605667
tenured boolean
false
tenuringAge uint
0

PromotionFailed

default profiling startTime 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Promotion of an object failed

Configuration enabled
default true
profiling true

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

EvacuationFailed

default profiling startTime 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Evacuation of an object failed

Configuration enabled
default true
profiling true

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

ConcurrentModeFailure

default profiling startTime 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Concurrent Mode failed

Configuration enabled
default true
profiling true

Field Type Description
gcId uint GC Identifier

GCCPUTime

default profiling startTime 20 21 22

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
88
realTime ulong: nanos
0
startTime long: millis
86914297917
systemTime ulong: nanos
9999999
userTime ulong: nanos
30000000
gcId uint
89
realTime ulong: nanos
4730000019
startTime long: millis
74988595625
systemTime ulong: nanos
1300000000
userTime ulong: nanos
649999999
gcId uint
62
realTime ulong: nanos
39999961
startTime long: millis
6511144958
systemTime ulong: nanos
10000000
userTime ulong: nanos
19999999

AllocationRequiringGC

startTime eventThread stackTrace 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

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

Configuration enabled stackTrace
default false true
profiling false true

Field Type Description
gcId uint Pending GC Identifier
size ulong: bytes Allocation Size

Examples 3
gcId uint
37
size ulong: bytes
56
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
51
lineNumber int
236
method Method
descriptor string
(Lakka/actor/ActorRef;Lakka/actor/ActorRef;IIIZ)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
edu/rice/habanero/benchmarks/uct/UctAkkaActorBenchmark$NodeActor
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
edu/rice/habanero/benchmarks/uct
type FrameType
Inlined
truncated boolean
false
startTime long: millis
30169188334
gcId uint
79
size ulong: bytes
32
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
67
lineNumber int
718
method Method
descriptor string
(Lscala/collection/immutable/RedBlackTree$Tree;)Lscala/collection/immutable/RedBlackTree$Tree;
hidden boolean
false
modifiers int
1
name string
blackWithRight
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/net
hidden boolean
false
modifiers int
49
name string
scala/collection/immutable/RedBlackTree$Tree
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
10613444208
gcId uint
56
size ulong: bytes
2048
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
16
lineNumber int
2849
method Method
descriptor string
(Ljava/lang/Runnable;)V
hidden boolean
false
modifiers int
1
name string
execute
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/util/concurrent/ForkJoinPool
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
type FrameType
Inlined
truncated boolean
false
startTime long: millis
47266518208

TenuringDistribution

default profiling startTime 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, SerialGC

Missing in: ParallelGC, ShenandoahGC, ZGC

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

Configuration enabled
default true
profiling true

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

Examples 2
age uint
11
gcId uint
14
size ulong: bytes
0
startTime long: millis
1540715125
age uint
14
gcId uint
5
size ulong: bytes
0
startTime long: millis
983426208

G1HeapRegionTypeChange

startTime 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Information about a G1 heap region type change

Configuration enabled
default false
profiling false

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

Examples 1
from G1HeapRegionType
Eden
index uint
22
start ulong: address
30110908416
startTime long: millis
1540666958
to G1HeapRegionType
Free
used ulong: bytes
0

ObjectCount

startTime every chunk 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

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

Configuration enabled period
default false everyChunk
profiling false everyChunk

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

Examples 3
count long
1205925
gcId uint
29
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
startTime long: millis
9171878750
totalSize ulong: bytes
28942200
count long
6731
gcId uint
1
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
702041958
totalSize ulong: bytes
430784
count long
1461337
gcId uint
22
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
13696186625
totalSize ulong: bytes
39236960

G1HeapRegionInformation

startTime duration every chunk 11 17 21 22

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Information about a specific heap region in the G1 GC

Configuration enabled period
default false everyChunk
profiling false everyChunk

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

Examples