8g物理内存-Xms4g-Xmx4g-Xmn2g-Xss1m-XX:MetaspaceSize=128m-XX:MaxMetaspaceSize=256m-XX:SurvivorRatio=8-XX:MaxDirectMemorySize=512m-XX:+UseConcMarkSweepGC-XX:CMSInitiatingOccupancyFraction=70-XX:+UseCMSInitiatingOccupancyOnly-XX:+UseCMSCompactAtFullC