I think the original post mentioned that GC was not running. can you take a thread dump when there is a pause and see what the threads are waiting on?
On Wed, Dec 14, 2011 at 1:56 PM, Kirk <[email protected]> wrote: > might be GC.. me be that JMeter's threads are all hung up in your server > doing stuff. > > Regards, > Kirk > On Dec 14, 2011, at 10:35 PM, Robin D. Wilson wrote: > > > I have a marginally complicated test case that performs a 'registration' > on > > my site. It gets the home page, POSTS a form, gets the response, POSTS > > another form, gets that response, and then completes. The test runs fine > > with 100 threads, and 30000 iterations - IF I don't "Retrieve All > Embedded > > Resources from HTML Files". In this mode, I am really testing the > throughput > > of my 'tomcat' application, not the other elements of my system. (I'm > > assuming that the other elements are being retrieved from our Content > Data > > Network instead of our main system in this case.) > > > > If I enable the "Retrieve All Embedded Resources from HTML Files" flag, > and > > tune the test down to 10 threads with 3000 total iterations, I notice a > very > > strange behavior. The test runs along at a pretty good clip for the first > > ~600 iterations (about 1 min, 25 seconds into the run), and then it just > > stops making requests for about 35 seconds. Then, it picks back up again > and > > runs for another 1 m 25s, and then stops again for 35 seconds... (NOTE: > with > > the 10 threads, 3000 total iterations - but with "Retrieve All > Embedded..." > > disabled - I don't see the 'stop' behavior either - so it isn't caused by > > tuning it down...) > > > > I recently added the "Perfmon Metrics Collector" to the test script, so I > > could see if one of the servers was maxed out - but it looks like all the > > servers are idle during the 'stop' period. Likewise, I added the Perfmon > for > > the "localhost" (running the JMeter test) to see if it was swamped - but > it > > too is idle during the 'stop'. I swapped out our network switch (the test > > environment is on an isolated network switch) with a _much_ higher > capacity > > switch - in case there was a network issue, still no change. > > > > I'm running out of ideas for things to check - so I thought I'd ask you > guys > > if you have any suggestions of things I should look at. > > > > My system consists of: > > > > WinXP - running JMeter 2.4.1 - driving the test script in GUI mode > > Server 1 - running Red Hat Linux, with "Apache (2.2.21)" as the web > > server - using AJP Proxy to Server 2 > > Server 2 - running Red Hat Linux, with Tomcat 7.0.21 as the App > > Server - connecting through Hibernate to Server 3 > > Server 3 - running Red Hat Linux with MySQL 5.x as the DB Server > > > > All 4 machines are running on a private switched network (32Gbs > backplane). > > > > The requests are downloading about 3MB total (per thread per iteration) > over > > 4 main URL requests, and 30+ 'Retrieve All Embedded' requests. > > > > At first I thought it was the network - but the new switch seemed to deny > > that thought (the old switch had a much slower backplane). Also, I'm > having > > no trouble collecting the PerfMon data during the 'stop' period - so the > > network is still functioning just fine... > > Then I thought it might be garbage collection on the tomcat - but I > watched > > the gc.log - and it doesn't do any GCs during the 'stop' period. > > Then I thought it might be the garbage collection on the JMeter side, so > I > > started the JMeter.bat from a 'cmd' prompt with gc logging enabled - it > > doesn't do any GCs during the 'stop' period either. > > > > The apache, tomcat, and DB are all 'idle' (no CPU to speak of, no network > > I/O, no disk I/O, etc.) during the 'stop' period. > > > > The JMeter box (WinXP) is doing very little during that time too (I > > attribute the little bit of activity to displaying the PerfMon graphs, > and > > Remote Desktop display to my desktop computer)... > > > > -- > > Robin D. Wilson > > Sr. Director of Web Development > > KingsIsle Entertainment, Inc. > > VOICE: 512-777-1861 > > www.KingsIsle.com > > > > > > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: [email protected] > > For additional commands, e-mail: [email protected] > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > >
