-XX:+UseParNewGC -XX:+ExplicitGCInvokesConcurrent -XX:TargetSurvivorRatio=90 -XX:MaxTenuringThreshold=31 -XX:+UseConcMarkSweepGC -XX:+UseCMSCompactAtFullCollection -XX:CMSInitiatingOccupancyFraction=50 -XX:CMSFullGCsBeforeCompaction=1
http://www.oracle.com/technetwork/java/faq-140837.html
http://www.oracle.com/technetwork/java/javase/tech/vmoptions-jsp-140102.html