tomcat-jetty-JVM调优

都是需要修改配置文件
jetty:
打开jetty根目录下的bin/jetty.sh文件，修改配置项JAVA_OPTIONS的配置即可

JAVA_OPTIONS="-server -Xms6G -Xmx6G -Xmn2G -XX:SurvivorRatio=32 -XX:MaxTenuringThreshold=5 -XX:+UseParNewGC -XX:+UseConcMarkSweepGC -XX:+UseCMSCompactAtFullCollection -XX:CMSFullGCsBeforeCompaction=0 -XX:+CMSClassUnloadingEnabled -XX:+CMSClassUnloadingEnabled -XX:+CMSParallelRemarkEnabled -XX:CMSInitiatingOccupancyFraction=85 -XX:SoftRefLRUPolicyMSPerMB=0 -XX:-ReduceInitialCardMarks -Dsun.rmi.dgc.client.gcInterval=3600000 -Dsun.rmi.dgc.server.gcInterval=3600000"

tomcat:
对catalina.sh优化JVM

一般是在开头添加JAVA_OPTS

# OS specific support.  $var _must_ be set to either true or false.

JAVA_OPTS="-server -Xms2048m -Xmx2048m -XX:PermSize=128M -XX:MaxNewSize=256m -XX:MaxPermSize=512m -Djava.awt.headless=true"

参考：http://www.imooc.com/article/details/id/253533
https://www.cnblogs.com/yanduanduan/p/5344407.html
https://www.cnblogs.com/101key/p/6876777.html