Problem Determination for WebSphere for z/OS

Chapter 20. WebSphere for z/OS traces and dumps 251

...Trace: 2005/08/09 19:06:19.729 01 t=7CC148 c=11.1 key=P8 (13007002)

ThreadId: 00000029

FunctionName: com.ibm.ws.webcontainer.servlet.ServletWrapper

SourceId: com.ibm.ws.webcontainer.servlet.ServletWrapper

Category: SEVERE

ExtendedMessage: BBOO0220E: SRVE0068E: Could not invoke the service() method

on servlet MemLeak. Exception thrown : java.lang.OutO

fMemoryError: JVMXE006:OutOfMemoryError, stAllocArray for executeJava failed

In the case of an OutOfMemory error, looking for the memory leak using the transaction dump

in IPCS is not useful. Java tools such as Heaproots or the Memory dump diagnostic for Java

are more effective in this case.

You can disable the generation of a TDUMP, but IBM does not recommend it.

For more information about TDUMP, refer to IBM Developer Kit and Runtime Environment,

Java 2 Technology Edition, Version 1.4.2, Diagnostics Guide, SC34-6358-01, for your version

of Java on z/OS.

20.6 Javadump

A Javadump produces files with diagnostic information that is related to the JVM and a Java

application captured at a point while it is run. For example, the information can be about the

operating system, the application environment, threads, native stack, locks, and memory. The

exact contents depend on the platform that you are running.

By default, a Javadump occurs when the JVM terminates unexpectedly. A Javadump can also

be triggered by sending specific signals to the JVM.

For more information about the Javadump, refer to IBM Developer Kit and Runtime

Environment, Java 2 Technology Edition, Version 1.4.2, Diagnostics Guide, SC34-6358-01,

for your version of Java on z/OS.

20.7 Heapdump

Heapdump is an IBM JVM facility that generates a dump of all of the live objects that are on

the Java heap, that is, those that are used by the Java application. It shows the objects that

are using large amounts of memory on the Java heap and what is preventing them from being

collected by the Garbage Collector.

For more information about the Heapdump refer to IBM Developer Kit and Runtime

Environment, Java 2 Technology Edition, Version 1.4.2, Diagnostics Guide, SC34-6358-01,

for your version of Java on z/OS.

Note: Javadump is also known as Javacore. This is not the same as a core file (that is, an

operating system feature that can be produced by any program, not just the JVM).

252 Problem Determination for WebSphere for z/OS