On 09.09.2009 19:44, keeplearning wrote: > > I have apache 2.2.3. Not sure how to find the tomcat version. We use > mod_proxy_ajp connector. During the test, I see high CPU usage and load on > both appservers. So, I don't think it's the issue of everything going to one > appserver. > > With what i read around, increasing maxClients does not help much. Ofcourse > I will try that but not that hopeful.
I don't know which is your platform, bot e.g. on Unix/Linux type platforms you can use ps with additional flags (e.g. -L) to list CPU usage per thread. That way you can first identify, whether your high cpu usage comes from one special thread or is distributed over lots of threads. Then you can do a couple of thread dumps (kill -QUIT), which go to catalina.out, and check, which of the threads were the ones, that had the high cpu load (and what they were doing). Depending on the platform you might have to convert the decimal thread number from ps to a hex number to compare with the tid or nid in the thread dumps. If you are using the tcnative connector, then make sure to use the latest version. It's the only peace in Tomcat I remember that produced high cpu load as a result of a bug. It's much more likely though, that the reason lies somewhere within your application. Regards, Rainer > Tim Funk-2 wrote: >> >> At this point, no one on the list will have a clue since we don't know >> 1) apache version >> 2) tomcat version >> 3) type of connector used, mod_proxy_ajp, mod_jk, or mod_proxy_http >> >> But if tomcat is saying All threads (250) are currently busy, waiting. - >> that means it is only configured to handle 250 workers. >> >> -Tim >> >> keeplearning wrote: >>> Where do I see # of apache workers and tomcat workers in the config file? >>> With what you said, shouldn't 2 tomcat servers handle 500 connections >>> (250 >>> *2)? >>> >>> Thanks a lot >>> Prakash >>> >>> >>> >>> funkman wrote: >>>> you have a config issue. I bet you have 250 apache workers (per server) >>>> and 250 tomcat workers(per server). >>>> >>>> But there are 500 apache workers (250 * 2). So in the worst case - you >>>> need tomcat to handle 500 connections. >>>> >>>> -Tim >>>> >>>> keeplearning wrote: >>>>> I am running a load test with 2 web (apache) and 2 appservers (tomcat). >>>>> I >>>>> am >>>>> noticing that after 250 users, I start seeing very high CPU usage and >>>>> very >>>>> high load. Below is the o/p from top command. I also saw this message >>>>> in >>>>> catalina.out: "SEVERE: All threads (250) are currently busy, waiting. >>>>> Increase maxThreads (250) or check the servlet status" --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
