how to genarate heap dump automatically in WAS 5

What do you mean by 'automatically'?

You can use kill -3 <pid> manually if that helps

Generate heap dump of Out Of Memory Condition option is available through JVM properties. 

Hi Praveen,

You can accomplish it by adding an environment entry like below :

In console Servers > Application servers > [appserver_name] > Process Definition > Environment Entries

New:

JAVA_DUMP_OPTS ONINTERRUPT(NONE),ONDUMP(JAVADUMP,HEAPDUMP),ONERROR(NONE),ONEXCEPTION(NONE),ONOUTOFMEMORY(JAVADUMP[3],HEAPDUMP[3])

It will create 3 javacores / heapdumps in a row when the OoM situation occurs in your jvm

Hope that helps

Gustavo

Thank You

From java 1.4.1 & above,  'java -Xdump' command can be used to generate heapdump. You can also generate thread dump & system dump using the same command with its respective options.

Refer: http://www-01.ibm.com/support/docview.wss?uid=swg21242497#Default_Dump_Agents

thank you