[Deploying Sakai] JVM GC tuning for Java 1.6

Stephen Marquard stephen.marquard at uct.ac.za
Thu Aug 19 02:30:16 PDT 2010

Hi all,

I recently asked about GC settings for java 1.6, as our GC behaviour got significantly worse when we moved from 1.5 to 1.6.

We've now updated our GC settings to:

-server -d64 -Xms5000m -Xmx5000m -XX:MaxPermSize=512m -XX:+UseConcMarkSweepGC -XX:+ExplicitGCInvokesConcurrent -XX:+CMSIncrementalMode -verbose:gc -XX:+PrintGCApplicationStoppedTime -XX:+PrintGCDetails -XX:+PrintGCTimeStamps

with good results. We were previously using:

-server -d64 -Xms5000m -Xmx5000m -Xmn1g -XX:MaxPermSize=512m -XX:+UseParNewGC -XX:+UseConcMarkSweepGC -XX:GCTimeRatio=19 -XX:SurvivorRatio=8 -XX:TargetSurvivorRatio=90 -XX:MaxTenuringThreshold=31 -verbose:gc -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+DisableExplicitGC




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