I see premature EOFs every time I get segmentation faults in a child. But then, that should be logged...
Hannes But then, that should be logged On 21 January 2011 19:02, Dave Steinberg <[email protected]> wrote: > On 1/21/2011 12:32 PM, Dave Steinberg wrote: >> >> Hi folks, first, this may be a tricky problem since it seems entirely >> inconsistent. Good times! >> >> I've noticed since switching to peruser that some requests seem to >> randomly return with what my load balancer (Pound) translates into a 500 >> error code of "Internal server error". Upon deeper investigation, Pound >> is not the problem, since I ran Apache jmeter directly against my web >> backend and produced similar results. >> >> I have a very simple script that intentionally takes a long time (~20 >> seconds) to complete its work. The script is: >> >> ==== >> #! /usr/bin/perl >> >> $| = 1; >> >> print "Content-type: text/html\n\n"; >> >> print "<html><head><title>trickling write test</title></head><body>\n"; >> >> for (my $i = 1; $i < 20; $i++) { >> print "--> $i <br>" ; >> sleep 1; >> } >> >> print "</body></html>"; >> >> exit 0; >> ==== >> >> If I run jmeter against that URL for a few hundred iterations, I get >> anywhere from 10-30% error rates. The error I'm getting isn't a HTTP >> error, but rather, a premature EOF (i.e. no HTTP response is sent). >> >> I cranked my LogLevel to debug, but so far I haven't seen anything in >> the logs that is interesting. Likewise, server-status shows 100% >> availability for all workers. >> >> My peruser config is: >> IdleTimeout 600 >> ExpireTimeout 1800 >> MinSpareProcessors 5 >> MaxSpareProcessors 15 >> StartProcessors 5 >> MinProcessors 0 >> #MaxProcessors 100 >> MaxProcessors 400 >> ServerLimit 3000 >> MaxClients 1500 >> MaxRequestsPerChild 1000 >> #MinMultiplexers 100 >> MinMultiplexers 15 >> MaxMultiplexers 200 >> MultiplexerIdleTimeout 600 >> ProcessorWaitTimeout 10 >> MaxCPUUsage 50 >> # works, but prevents cores >> #MultiplexerChroot /var/empty >> >> # define a default processor >> <Processor global_default> >> User www >> Group www >> </Processor> >> ServerEnvironment global_default >> >> Any suggestions welcome, including debugging tips. :/ > > Just following up quickly - I did some more poking with the test script. I > get approximately a 2% error rate when the loop variable is dropped to '2', > i.e. 2 seconds per request, minimum. At 0 or 1, I can't detect any errors > in 1000 iterations. > > Do other people see similar results in their peruser setups? > > PS: 'ab -n 20 -c 1000' ought to produce equivalent results to what I'm > seeing in jmeter. > > -- > Dave Steinberg > http://www.geekisp.com/ > http://www.steinbergcomputing.com/ > http://www.redterror.net/ > _______________________________________________ > Peruser mailing list > [email protected] > http://www.telana.com/mailman/listinfo/peruser > _______________________________________________ Peruser mailing list [email protected] http://www.telana.com/mailman/listinfo/peruser
