Java app threading problem on HP-UX

[Gilles Compienne]

Hello, I am using an application using Weblogic and Java on a HP9000N and I am getting some deadlocking problem (but only on HP-UX). I am trying to localize the origine of the problem (Java?, Weblogic?, our application?) and for the moment I suspect it could be a threading problem in the JVM itself.

The reason why I believe this is that when I try to request the JVM for a thread dump (Sending a SIGQUIT to the JVM process) it works usually well except when the locking happen.

Do you know if the thread dump request should always work or if there are situations where it is expected that the JVM will not answer the SIGQUIT?

I am also asking myself if this could be related to PHKL_24943 which has been recently called back (but which apparently was made to solve some threading problems).

Thanks for your help.

Regards,

Gilles.

[Christopher McCray_1]

PHKL_24943 has come with a warning in which inactive threads can become corrupt, where when called again can cause system panic. I've attached the exact email from hp for the exact lingo. I have been told that it has been a rare occurrance, so I believe it to be a judgement call on your part. I have delayed installing it and instead kept 22504 and others like 22589, 22568, etc.

Hope this helps
Chris

[Gilles Compienne]

I agree about PHKL_24943, I got the same warning from HP.

It is why I was also asking myself if the fact that I was not able to get a thread dump from the JVM could also have been a clue...

Have you tried the JVM thread dump? (by doing kill -3 JVM_PROCESS_NUMBER). If yes, did it work always reliably? Or has it the tendancy do not give any result for a yes or for a no?? (Because if it is a reliable tool then I would really suspect that something strange is happening).

Thanks again for your help,

Gilles.