How to create Heap dump with time stamp

Solution Verified - Updated

Environment

  • Java
    • Oracle(Sun) JDK
    • Open JDK

Issue

  • Is it possible to create Heap Dump with time stamp ?

Resolution

JDK / Version

OpenJDK / Oracle JDK 11

  1. HeapDumpOnOutOfMemoryError
  2. jcmd
  3. jmap - Java Process
  4. jmap - Core File
  5. JConsole

OpenJDK / Oracle JDK 1.8

  1. HeapDumpOnOutOfMemoryError
  2. jcmd
  3. jmap - Java Process
  4. jmap - Core File
  5. jmap - OpenShift
  6. JConsole
  7. JBoss JMX Console

OpenJDK / Oracle JDK 1.7

  1. HeapDumpOnOutOfMemoryError
  2. jmap - Java Process
  3. jmap - Core File
  4. JConsole
  5. JBoss JMX Console

OpenJDK / Oracle JDK 1.6

  1. HeapDumpOnOutOfMemoryError
  2. jmap - Java Process
  3. jmap - Core File
  4. JConsole
  5. JBoss JMX Console

OpenJDK / Oracle JDK 1.5

  1. HeapDumpOnOutOfMemoryError
  2. jmap - Java Process
  3. jmap - Core File
  4. HeapDumpOnCtrlBreak
  5. runhprof

IBM

  1. OutOfMemoryError

HP

  1. HeapDumpOnOutOfMemoryError

JRockit

  1. jrcmd

Reference

-XX:+HeapDumpOnOutOfMemoryError

   OpenJDK
   Sun/Oracle JDK 1.4.2\_12 (except with throughput collector -XX:+UseParallelGC, which requires 1.4.2\_15)
   Sun/Oracle JDK 1.5.0_07
   Sun/Oracle JDK 1.6.0 and all later ones.
   HP-UX JDK 1.4.2_11
   JRockit R28 and up

Notes:

  • Produces dumps in hprof format, a binary, platform-independent format.

  • By default the heap dump is created in the directory defined by the user.dir environment variable and named java_pid<pid>.hprof, where <pid> is the  Java process id. For JBoss, check boot.log to see the value of user.dir (e.g. $JBOSS_HOME/bin).

  • Use the -XX:HeapDumpPath option to specify a different location (e.g. -XX:HeapDumpPath=/mypath/). If you specify a directory Java will write it there using the default file name, including the process id. If you specify a file name (e.g. -XX:HeapDumpPath=/mypath/myheapdump.hprof) heap dumps will overwrite each other. Unless disk space is a concern, you typically would not want to overwrite heap dumps and lose data.

  • This option does not impact performance (until the heap is actually written out); it is simply a flag to indicate that a heap dump should be generated when the first thread throws OutOfMemoryError.

  • It is typically a best practice to use this JVM option, as it provides critical information in case of a memory error.

  • For JBoss EAP, see Configuring JVM SETTINGS for instructions on setting command line parameters. This covers standard, clustered, and domain mode configuration. You can set the same command line parameters as you would for an Java-based application.

See Java heap dump not created on OutOfMemoryError for details on why a heap dump may not be created even when the jvm parameter -XX:+HeapDumpOnOutOfMemoryError is present

-XX:+HeapDumpOnCtrlBreak

Effective from Sun JDK 1.5.0_14, but note HeapDumpOnCtrlBreak it does not work in JDK 1.6 and beyond.

  • Produces dumps in hprof format, a binary, platform-independent format.

  • kill -3 JAVA_PID (or Ctrl-Break on Windows) will cause the heap dump to be created (in addition to a stack trace). For Windows, you can use the Content from www.latenighthacking.com is not included.SendSignal utility to send the Ctrl-Break signal from the command line. See the following document for details using SendSignal: How do I generate a Java thread dump on Windows?.

  • The heap dump will be created in the directory defined by the user.dir environment  variable and named java_pid<jboss_pid>.hprof.<date>.<time>.  For JBoss, check boot.log to see the value of user.dir (e.g. $JBOSS_HOME/bin).

jmap - java process

Heap dump is created in the directory where the jmap command is issued. If using RHEL's OpenJDK, ensure the corresponding devel package is installed for jmap (java-1.6.0-openjdk-devel or java-1.7.0-openjdk-devel).

  • Sun JDK 1.5: (excluding Windows or Linux Itanium)

    • jmap -heap:format=b <JAVA_PID>

  • Sun JDK 1.5 64-bit: (excluding Windows or Linux Itanium)

    • jmap -J-d64 -heap:format=b <JAVA_PID>

Notes:

  • You need to execute jmap as the same user as the java process. Please see this article for more details.

  • Heap dump is created in the directory where the jmap command is issued.

  • Heap dump file is named heap.bin, or you can name it.

  • This syntax also works on Sun JDK 1.6; however, the heap dump will not include some advanced 1.6 features (e.g. stack traces for stack roots) and will run slower than the 1.6 syntax. Therefore, do not use the 1.5 syntax on a 1.6 JVM.

  • OpenJDK 1.6/1.7/1.8:

    • jmap -dump:format=b,file=heap.hprof JAVA_PID

  • OpenJDK 1.6/1.7/1.8 64-bit

    • jmap -J-d64 -dump:format=b,file=heap.hprof JAVA_PID

  • OpenJDK 1.6/1.7/1.8 (Windows):

  • OpenJDK 11:

    • jmap -dump:format=b,file=heap.hprof JAVA_PID

Notes:

  • Heap dump is created in the directory where the jmap command is issued.
  • Heap dump file is named according to file attribute.
  • Available on Windows, but not on Linux Itanium.
  • The -J option does not work on Windows or JDK11.
  • Heap dump file generated is only accessible to the user who is the JBoss process owner.

jmap - core file

jmap blocks when creating the heap dump, and with large heaps, this can take a very long time.
In these cases it is often much faster to get a core and then run jmap to extract a heap dump from the core.
It is typically best to create the heap dump on the same box where the core was created to avoid environment differences.

  • Sun JDK 1.5:

    • jmap -heap:format=b JAVA_HOME/bin/java COREFILE > heap.hprof 2>&1

  • Sun JDK 1.5 64-bit:

    • jmap -J-d64 -heap:format=b JAVA_HOME/bin/java COREFILE > heap.hprof 2>&1

Notes:

  • Be sure to specify the path to the java executable relevant to the core.

  • Not available on Windows or Linux Itanium. For Windows on 1.5, consider -XX:+HeapDumpOnCtrlBreak or third party tools such as Eclipse Memory Analyzer Tool (MAT) for capturing a heap dump.

  • This  syntax also works on Sun JDK 1.6; however, the heap dump will not  include some advanced 1.6 features (e.g. stack traces for stack roots)  and will run slower than the 1.6 syntax. Therefore, do not use the 1.5  syntax on a 1.6 JVM.

  • Sun JDK 1.6, OpenJDK:

    • jmap -dump:format=b,file=heap.hprof JAVA_HOME/bin/java COREFILE > heap.out 2>&1

  • Sun JDK 1.6, OpenJDK 64-bit (not Windows):

    • jmap -J-d64 -dump:format=b,file=heap.hprof JAVA_HOME/bin/java COREFILE > heap.out 2>&1

  • Sun JDK 1.6 (Windows):

    • jmap -dump:format=b,file=heap.hprof JAVA_HOME/bin/java COREFILE > heap.out 2>&1

Notes:

  • Be sure to specify the path to the java executable relevant to the core.
  • Available on Windows, but not on Linux Itanium.
  • The -J option does not work on Windows.

jmap - OpenShift

POD=your-pod-name; PID=$(oc exec $POD ps aux | grep java | awk '{print $2}'); oc exec $POD -- bash -c "for x in {1..10}; do jstack -l $PID >> /opt/eap/standalone/tmp/jstack.out; sleep 2; done"; oc rsync $POD:/opt/eap/standalone/tmp/jstack.out .

See: https://access.redhat.com/articles/3135421#gather-a-heap-dump-from-a-running-container-4a

JRockit R28 and up

jrcmd <JAVA_PID> hprofdump filename=abc.hprof

Notes:

IBM JDK

A portable heap dump (phd) format heap dump is created in the temp directory (e.g. /tmp/) when OutOfMemoryError is thrown.

JConsole

Starting with Sun JDK 1.6 you can Content from docs.oracle.com is not included.get a heap dump from JConsole:

  1. Go to MBeans/com.sun.management/HotSpotDiagnostic/Operations.
  2. Enter "heap.hprof" in the p0 textbox and "true" in the p1 textbox.
  3. Click the dumpHeap button.

The heap dump will be created in the directory defined by the user.dir environment  variable and named heap.hprof.  For JBoss,  check boot.log to see the value of user.dir (e.g. $JBOSS_HOME/bin).

runhprof

  • Sun JDK 1.3, 1.4 (deprecated in Sun JDK 1.5):

  • Enabled with the following JVM option:

          -Xrunhprof:heap=dump,file=dump.hprof,format=b

Notes:

  • kill -3 JAVA_PID (or Ctrl-Break on Windows) will cause the heap dump to be created (in addition to a stack trace). You can also use the Content from www.latenighthacking.com is not included.SendSignal utility on Windows to send the Ctrl-Break from the command line.

  • Produces dumps in hprof format, a binary, platform-independent format.

  • dump.hprof.TMP and dump.hprof placeholder files are created in the directory defined by the user.dir environment  variable and written to when kill -3 JBOSS_PID or Ctrl+Break is executed.  For JBoss,  check boot.log to see the value of user.dir (e.g. $JBOSS_HOME/bin).

  • Taking more than one heap dump will cause the following error and crash the JVM: "HPROF ERROR: Mis-match on instance size in instance dump" due to the following bug:
    Content from bugs.sun.com is not included.Content from bugs.sun.com is not included.http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6379450

  • Run java -Xrunhprof:help for configuration options.

JBoss JMX Console

  1. Open JBoss EAP 4.x/5.x JMX console, and go to the "HotSpotDiagnostic" MBean under com.sun.management.
  2. For the "dumpHeap" operation, enter "heap.hprof" for the first parameter and "true" for the second parameter.
  3. Press Invoke

It will create a heap dump called "heap.hprof" in JBoss' working directory (probably $JBOSS_HOME/bin). Alternatively, you can specify a full path for the first parameter.

jcmd

  • Valid for Oracle JDK and OpenJDK 7 and 8. This is Oracle's preferred method since JDK 8.
  • jcmd JAVA_PID GC.heap_dump -all=true FILENAME.hprof
  • The heap dump file will be created on the directory which was used to start the application
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