Tomcat Application Server freezes

Questions about YourKit Java Profiler
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Kuchenwolf
Posts: 1
Joined: Mon Dec 15, 2014 3:25 pm

Tomcat Application Server freezes

Post by Kuchenwolf »

Lately, our Tomcat Application Server is having global freezes, during which it can not be accessed at all.
It starts with one second freezes each 5 seconds and gets worse until the freezing phases become longer than the working phases! We had freezes up to 40 seconds. Rarely, it gets better if we let it run long enough, but usually we restart the server.

What's interesting, while our server is freezing up the yourkit thread takes up close to 100% thread utilization, which we have confirmed manually as well (with the threadmxbean.getThreadCpuTime method)

Do you have any advice on what could be causing our problem and how to fix it?

I am attaching a screenshot of what the yourkit profiler is showing when the server freezes up.
The blank spots are when the server is not reacting.
Image
Anton Katilin
Posts: 6172
Joined: Wed Aug 11, 2004 8:37 am

Re: Tomcat Application Server freezes

Post by Anton Katilin »

Hi,

Which version do you use?

Could you please provide a performance snapshot of that application. Please capture it, zip the .snapshot file and send it attached to [email protected]

Also, could you please provide the profiler agent logs from the remote machine at ~/.yjp/log. Please also zip and attach.

Anyway, you have the stack telemetry enabled:
http://www.yourkit.com/docs/java/help/threads.jsp

It may add overhead especially when you have many threads. The EE server integration wizard suggests to disable it in production mode. It offers other settings too to control the overhead.
I would recommend to use the wizard and choose the Production option if you haven't done it yet.
http://www.yourkit.com/docs/java/help/p ... remote.jsp

Best regards,
Anton
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