What do these HPROF errors mean?

Question

I'm seeing the following errors in my console logs:

HPROF ERROR: unable to resolve a method id
HPROF ERROR: got NULL trace in obj_alloc
HPROF ERROR: duplicate obj_id in object_alloc
HPROF ERROR: unable to resolve a method id
HPROF ERROR: got NULL trace in obj_alloc
HPROF ERROR: unable to resolve a method id
HPROF ERROR: got NULL trace in obj_alloc
HPROF ERROR: unable to resolve a method id
HPROF ERROR: got NULL trace in obj_alloc
HPROF ERROR: unable to resolve a method id
HPROF ERROR: got NULL trace in obj_alloc
HPROF ERROR: class ID already in use

I'm running on the BEA Weblogic App Server 8.1 with the SUN 1.4.2-12 JDK.

I'm passing these debugging flags to the JVM at startup:

-verbose:gc -XX:+PrintGCTimeStamps -XX:+PrintGCDetails -Xrunhprof:heap=sites,format=a,file=server1.endurance.txt

The error is output almost immediately after starting the server.

Any ideas what the errors mean?

Answer 1

It could be either

• a bug in the JVM, try using a more up to date JVM and see if you get the same problem.
• you have a JNI library which is creating objects incorrectly.

Answer 2

I think this reported bug may help you tracing you problem.

Synopsis: GetThreadGroupInfo crashes if Thread Group name is null (jvmpi too)

Reported Against: 1.4.2_03 , tiger-beta2

Release Fixed 1.5(tiger-b56)

Evaluation: Legacy java.lang.ThreadGroup allows the name to be null so the vm needs to allow for this.

As you are using a similar jvm I suggest to check the test code provided in the bug report to determine whether you have found the same bug.