Finally, here are our startup opts as it pertains to GC if it helps: -XX:+HeapDumpOnOutOfMemoryError -XX:PermSize=256m -XX:MaxPermSize=256m -Xmx5120m -Xms5120m -Xss128k -XX:ParallelGCThreads=20 -XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:SurvivorRatio=8 -XX:TargetSurvivorRatio=90 -XX:MaxTenuringThreshold=31 -XX:+AggressiveOpts -Xloggc:/var/tmp/gc.log
On Fri, Aug 8, 2008 at 11:59 PM, pc3 <[EMAIL PROTECTED]> wrote: > > Oh yeah, and we're using tomcat as the servlet engine.. thanks! > > > pc3 wrote: >> >> hey all - >> >> so i've spent the past two weeks trying to figure out why my large scale >> application (200m page views per month) is having some serious, yet >> random, spikes in response times. >> >> we've got an app running under gero 1.1.1, using hibernate, mysql, etc. >> i've got the response times down in general by adding memcaching and other >> optimizations but we still see the spikes.. e.g. most of our actions >> return in 0.1 sec, but occasionally (and often enough!) .. we'll see a >> random spike up to 30s from different machines in our cluster. >> >> so for kicks tonight i tried running a test against all of our app servers >> not for an action but for a plain .txt file ... and guess what... spiky >> responses just from the txt file! a 4.9kb text file! look: >> >> $profileUrl /blah/Languages.txt >> Host 192.168.1.100 >> Time taken for tests: 8.555825 seconds <<<<<<<<<<<< >> Host 192.168.1.101 >> Time taken for tests: 0.2064 seconds >> Host 192.168.1.108 >> Time taken for tests: 0.1436 seconds >> Host 192.168.1.104 >> Time taken for tests: 0.1667 seconds >> Host 192.168.1.112 >> Time taken for tests: 0.1444 seconds >> Host 192.168.1.117 >> Time taken for tests: 0.4575 seconds >> Host 192.168.1.118 >> Time taken for tests: 0.2015 seconds >> Host 192.168.1.119 >> Time taken for tests: 0.2003 seconds >> Host 192.168.1.120 >> Time taken for tests: 0.1713 seconds >> Host 192.168.1.121 >> Time taken for tests: 7.22861 seconds <<<<<<<<<<<< >> Host 192.168.1.122 >> Time taken for tests: 0.1615 seconds >> >> Here are some things to go on: >> 1) we still host a few swfs from these servers that are hit frequently. >> could these be causing some kind of blocking? >> 2) we have a method in our application that acts as a proxy, taking a url >> as a parameter, fetching the url then dumping it to the response >> >> I'm open to any ideas or suggestions as to what could be causing the >> spikiness of response times here for a txt file.. one that never even hits >> our java code. >> >> Thanks very much all... >> >> > > -- > View this message in context: > http://www.nabble.com/large-scale-app..-random-spiking-on-even-static-files%21-tp18902003s134p18902031.html > Sent from the Apache Geronimo - Users mailing list archive at Nabble.com. > >
