out of memory issues on IBM AIX and IBM JDK 1.4.2 J9 version

[Former Member]

Hi,

We are having out of memory issue on IBM AIX 5.3 version and IBM JDK 1.4.2 J9. All the settings for jvm parameters have been

made as per sap recommendations. Now that we need to debug this issue using some java profiler tool. We tried using Sherlok

but this does't seem to work on AIX platform. SAP Memory analyzer is a great tool but unfortunately is not supported with IBM JDK.

so what is the best way to troubleshoot out of memory heap issues ? which tools needs to be used for ibm platform and ibm jdk ?

[Former Member · Accepted solution]

Hi,

You can get the HeapDump Analyzer for analyzing IBM AIX heapdumps from the below mentioned link.

http://www.alphaworks.ibm.com/tech/heapanalyzer

http://www-1.ibm.com/support/docview.wss?uid=swg21190608

Prerequistes for obtaining a heapdump:

1.You have to add -XX:+HeapDumpOnOutOfMemoryError to the java options of the server (see note 710146,1053604) to get a heap dump on its occurance, automatically.

2.You can also generate heapdumps on request :

Add -XX:+HeapDumpOnCtrlBreak to the java options of the server

(see note 710146).

Send signal SIGQUIT to the jlaunch process representing the

server e.g. using kill -3 <jlaunch pid> (see note 710154).

The heap dump will be written to output file java_pid<pid>.hprof.<millitime> in:

/usr/sap/<SID>/<instance>/j2ee/cluster/server<N> directory.

Both these parameters can be set together too to get the benefit of both the approaches.

Regards,

Sandeep.

Edited by: Sandeep Sehgal on Mar 25, 2008 6:51 PM

[Former Member]

Hi,

IBM Heapdumps can only be analyzed using IBM Heapdump Analyzer. You could download the latest version from www.ibm.com

Also, please make sure the system is configured to generate heapdumps and all the recommendations in SAP Notes 723909 & 716927 are done correctly.

Despite the latest patches and correct parameter configuration, it is likely that the system goes into Outofmemory crash. The running applications need more memory than the recommended. There is a memory leak in the application. Bug with JVM. This can be identified using the heapdump almost always.

Hope this helps.

Regards,

Snehal

[Former Member]

Out of memory issues usually get fixed by applying the latest patches. Please also have a look at the recently updated sap note 1024700 which should fix your issue.

Regards,

Vince