Application goes into hang state

Hi Mwadhwa,

If a thread appears with Muxer in its name and is either doing processSockets() or blocked for lock-in processSockets() ignore these as Weblogic internal housekeeping threads.

Observing Muxer threads to be blocked is not an issue and this is normal behavior. You should not worry about this.

The muxer threads contend for the poll lock to poll on the file descriptors, so a large number of threads does not add any benefit. One Muxer thread is usually in the poll function, while the others are available to process requests. The polling thread is visible in a thread dump.

Hello Manoj!

 Greetings. I reviewed your 'ExecuteThread', which had following stack trace:

weblogic.socket.PosixSocketMuxer.processSockets(PosixSocketMuxer.java:93)
weblogic.socket.SocketReaderRequest.run(SocketReaderRequest.java:29)
weblogic.socket.SocketReaderRequest.execute(SocketReaderRequest.java:42)
weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:145)
weblogic.kernel.ExecuteThread.run(ExecuteThread.java:117) 

I don't think they will cause any problem. Please details please refer to this post 

How to diagnose this problem?

There could be several reasons why application is goes into hang state. Some of the reasons are:

• Garbage collection pauses
• Network connectivity
• Load balancer routing issue
• Heavy CPU consumption of threads
• Operating System running with old patches
• Memory Leak
• DB not responding properly

:

:

 So just thread dump is not enough to diagnose the problem. You can use the open source yCrash script which will capture 360-degree application level artifacts (like GC logs, 3 snapshots of thread dumps, heap dumps) and system level artifacts (like top, top -H, netstat, vmstat, iostat, dmesg, diskusage, kernel parameters...). Once you have these data, either you can manually analyze them or upload it to yCrash tool, which will analyze all these artifacts and generate one unified root cause analysis marrying all these artifacts. It can indicate the root cause of the problem.