On 23/10/2012 19:46, Charles Richard wrote: > With wc removed, it looked like the following: > > tcp 0 0 127.0.0.1:8009 127.0.0.1:37744 > ESTABLISHED > tcp 0 0 127.0.0.1:8009 127.0.0.1:36976 > ESTABLISHED > tcp 0 0 127.0.0.1:8009 127.0.0.1:35695 > ESTABLISHED > tcp 0 0 127.0.0.1:8009 127.0.0.1:39022 > ESTABLISHED > > At the exception of a few close_wait and a few fin_wait2. > > If in my jstack analysis, all worker threads are running and all GC threads > are running and my server was CPU bound, would i be correct in assuming > Garbage collection was killing tomcat? Tomcat would eventually not respond > anymore which I was trying to understand why as my jstack dump shows > TP-Processor threads waiting.
One thread dump from jstack is interesting but not particularly informative. If you see the same in a series of thread dumps, taken a few seconds apart then you can tell what's happening. Alternatively... like Daniel suggested, you do all of the above and more in a nice shiny GUI, where you don't have to guess what the threads are doing & where you can see a GC graph alongside at the same time. We _strongly_ recommend getting JMX set up & using VisualVM to see what's happening... p > Thanks! > > Cheers, > Charles > > On Tue, Oct 23, 2012 at 2:22 PM, Daniel Mikusa <dmik...@vmware.com> wrote: > >> On Oct 23, 2012, at 12:10 PM, Charles Richard wrote: >> >>> Hi, >>> >>> Thanks for the reply! >>> >>> The command was the following: >>> >>> [root@mysandbox tmp]# netstat -an | grep 8009 | wc >>> 856 5136 76184 >> >> What output do you get if you remove the "wc" command? >> >> >>> How should i interpret this? I thought this meant that 856 threads were >>> open while my MaxThreads is 750. >> >> This is not going to accurately give you a count of thread use. Don't use >> this command for that purpose. If you want to see thread usage, look at >> jvisualvm, jstack, or jconsole. All of these will give you accurate counts. >> >> >>> I'm trying to understand if all my >>> workerThreads are busy (hence trying the jstack dump) and then if they >> are, >>> not sure how I would do this but try to figure out on what they're busy. >> >> To figure out what is going on you have a couple choices: >> >> 1.) Use a profiler. YourKit is a good one, but not free. >> 2.) Use "top -H" in combination with jstack (or kill -3). >> >> In most cases a profiler is the best way to go. The top method is mainly >> useful when something is consistently consuming a large portion of the CPU. >> >> Dan >> >> >> >>> My OS is CentOS 5.8 for my sandbox and Red Hat 5.8 for my production >> boxes. >>> >>> Thanks, >>> Charles >>> >>> On Tue, Oct 23, 2012 at 12:25 PM, Daniel Mikusa <dmik...@vmware.com> >> wrote: >>> >>>>>> Hi, >>>>>> >>>>>> I'm testing performance of our Java application in Tomcat (6.0.30) and >>>> we >>>>>> have maxThreads set to 750. I noticed that when i did a netstat -an | >>>> grep >>>>>> my_ajp_port, i saw around 860 connections. >>>> >>>> That does not necessarily mean that you have 860 threads running. What >>>> are you trying to determine by running this command? If you want to see >>>> the number of threads, use jconsole, jvisualvm or jstack. >>>> >>>> Also, if you include the output of "netstat -an | grep my_ajp_port" and >>>> what OS you are running, someone on the list might be able to better >>>> explain the output from the command. >>>> >>>> >>>>>> I was expecting to see > 750 Worker Threads in my stack since some >> extra >>>>>> worker threads are needed by Tomcat. What i saw was around 60 worker >>>>>> threads in the trace. >>>> >>>> This would be the correct number of threads in use. >>>> >>>> Dan >>>> >>>> >>>>>> >>>>>> Any suggestions/ideas on why that would be? >>>>>> >>>>>> Cheers, >>>>>> Charles >>>>>> >>>> >>>> >>>> --------------------------------------------------------------------- >>>> To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org >>>> For additional commands, e-mail: users-h...@tomcat.apache.org >>>> >>>> >> >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org >> For additional commands, e-mail: users-h...@tomcat.apache.org >> >> > -- [key:62590808]
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