appropriate tomcat 5.5 start-up parameters balance jvm severely high demand, infinite store web application?

we have recently migrated large, high proceed web concentration tomcat 5.5 tomcat 4 have beheld rare slack function appears associated jvm pauses. method run the concentration support increasing bucket over tomcat 4, customary jvm parameters set tuned per below, i am anticipating someone tomcat jvm tuning trust critique anything approaching catastrophic tomcat 5.5 install. note also lift over before versions java (we controlling tomcat 4 java 1.6 parameters successfully time, nonetheless competence have introduced assistance rubbish collection java 1.4 basement the tomcat 4 exercise enlarged time, competence doing some-more mistreat good).

some notes:

• application memory footprint is
  around 1gb, substantially rather over.


• cpu an emanate - machines
  apportionment app (load balanced) are
  < 30% cpu


• lots headroom physical memory machines.


• -xx:maxpermsize=512m wholly parameter total biased 5.5 stand reactive an outofmemory permgen space emanate (which solved).


• running java 1.6, solaris os

-server -xms1280m -xmx1280m -xx:maxpermsize=512m -xx:parallelgcthreads=20 -xx:+useconcmarksweepgc -xx:+useparnewgc -xx:survivorratio=8 -xx:targetsurvivorratio=75 -xx:maxtenuringthreshold=0 -xx:+aggressiveopts -xx:+printgcdetails -xx:+printgctimestamps -xx:-traceclassunloading -dsun.io.usecanoncaches=false -dsun.net.client.defaultconnecttimeout=60000 -dsun.net.client.defaultreadtimeout=60000