high CPU usage on tomcat 7

Hi! I'm periodically getting unduly high (100%) CPU usage by the tomcat process on my server. This problems happens intermittently, several times a week. When the server goes into this high CPU it does not come back (and becomes unresponsive to new requests), and the only recourse is to

Re: high CPU usage on tomcat 7

Kirill Kireyev kir...@instagrok.com wrote: Hi! I'm periodically getting unduly high (100%) CPU usage by the tomcat process on my server. This problems happens intermittently, several times a week. When the server goes into this high CPU it does not come back (and becomes unresponsive to new

Re: high CPU usage on tomcat 7

This is probably due to out of memory, I have the same problem on my ubuntu ci machine Did you monitor your tomcat with jmx ? Jeff Le 27 sept. 2012 17:39, Kirill Kireyev kir...@instagrok.com a écrit : Hi! I'm periodically getting unduly high (100%) CPU usage by the tomcat process on my

RE: high CPU usage on tomcat 7

I agree; we have reproducible instances where PermGen is not set to our requirements on the Tomcat startup parameters and it will cause a lockup every time. Do some JMX monitoring and you may discover a memory spike that's killing Tomcat. Bill -Original Message- From: Jeff MAURY

Re: high CPU usage on tomcat 7

Hi Kirill, Like Mark, Bill and Jeff said, those threads are normal request-processing threads. I have included a script that might help with isolating high CPU issues with Tomcat. Also, I think it might be helpful to see how the Java heap is performing as well. Please bring up Jconsole and let

Re: high CPU usage on tomcat 7

Hi Kirill, I mistook that the CPU issue clears itself. Sorry. It may or may not be related to Garbage-collection settings then. -Shanti On Thu, Sep 27, 2012 at 2:17 PM, Shanti Suresh sha...@umich.edu wrote: Hi Kirill, Like Mark, Bill and Jeff said, those threads are

Re: high CPU usage on tomcat 7

Thanks for all the advice everyone! There is a possibility that the CPU is caused by an app thread - I am looking into that possibility. Will let you know when I find out more. Thanks, Kirill On 9/27/12 12:17 PM, Shanti Suresh wrote:

maxHTTPHeaderSize, and specific header lengths

I have a question about maxHttpHeaderSize [0]. In Apache httpd, there are two different parameters that affect the maximum size of an HTTP header, limitRequestFieldSize and limitRequestLine. [1] These configuration values specify about 8 kilobytes per _line_ in the incoming request. However, in