Showing posts with label JVM. Show all posts
Showing posts with label JVM. Show all posts

Friday, June 21, 2013

IBM Java core file

Description

An IBM Java core file is a snapshot generated by the IBM JVM as a result of:

  • Severe events such as a java.lang.OutOfMemoryError event.
  • User signal (action) sent to the JVM such as kill -3 <Java PID>.

Sample file

javacore.20130522.091935.14024730.0008.txt

NULL           ------------------------------------------------------------------------
0SECTION       TITLE subcomponent dump routine
NULL           ===============================
1TISIGINFO     Dump Event "systhrow" (00040000) Detail "java/lang/OutOfMemoryError" received
1TIDATETIME    Date:                 2013/05/22 at 09:25:36
1TIFILENAME    Javacore filename:    <App Folder>/javacore.20130522.091935.14024730.0008.txt
NULL           ------------------------------------------------------------------------
0SECTION       GPINFO subcomponent dump routine
NULL           ================================
2XHOSLEVEL     OS Level         : AIX 6.1
2XHCPUS        Processors -
3XHCPUARCH       Architecture   : ppc64
3XHNUMCPUS       How Many       : 12
Possible causes
……………………………………………………………………………………………
0SECTION       THREADS subcomponent dump routine
NULL           =================================
NULL           
1XMCURTHDINFO  Current Thread Details
NULL           ----------------------

……………………………………………………………………………………………
0SECTION       CLASSES subcomponent dump routine
NULL           =================================
1CLTEXTCLLOS        Classloader summaries
……………………………………………………………………………………………

Data content & purpose

  • IBM JVM thread dump analysis (thread lock contention, deadlock, thread chains, execution snapshot etc.)
  • Class loader analysis (# instances, leak patterns etc.).
  • JVM runtime arguments review.
  • Last GC activity history.

References and Case Studies