Java process is hanging for no apparent reason

java, linux

Solution

I doubt anyone can give you an explanation since there are lots of possible reasons and not nearly enough information. However, I suggest that you `jstack` the process once it's hung to figure out what the threads are doing, and take it from there. It sounds like a deadlock or thrashing of some sort.

Problem

I am running a Java process with Xmx2000m, the host OS is linux centos, jdk 1.6 update 22. Lately I have been experiencing a weird behavior in the process, it becomes totally unresponsive with no apparent reason, no logs, no errors, nothing.. I am using jconsole to monitor the processor, heap and Perm memory are not full, threads and loaded classes are not leaking.. Explanation anyone?

Original source