监控java虚拟机

 

jstat -gcutil `ps -ef|grep java|awk '{print $2}'` 1000

jstat -gccapacity `ps -ef|grep java|awk '{print $2}'` 1000

 

jmap -histo `ps -ef|grep java|awk '{print $2}'` 1000

jmap -dump:format=b,file=java_dump `ps -ef|grep java|awk '{print $2}'` 1000

 

 

 

java -Xms30m -Xmx30m -Xmn10m -XX:+UseParallelGC -verbose:gc -XX:+PrintGCDetails -XX:+Print

GCTimeStamps -Xloggc:gc.log -XX:+PrintHeapAtGC  SummaryCase

jstat : jstat -gcutil `ps aux|grep Summ|awk '{ print $2 }'` 1000 10

线上配置：

-server -Xms4g -Xmx4g -Xmn2560m -XX:SurvivorRatio=10 -XX:+UseConcMarkSweepGC -XX:+UseCMSCompactAtFullCollection -XX:CMSMaxAbortablePrecleanTime=5000 -XX:+CMSClassUnloadingEnabled -XX:CMSInitiatingOccupancyFraction=80 -XX:PermSize=96m -XX:MaxPermSize=256m -XX:+UseCompressedOops

google perm tools

export LD_PRELOAD=/usr/local/lib/libtcmalloc.so

env HEAPPROFILE=oomcase.hprof java -Xmn10m -Xms1536m -Xmx1536m NativeMemoryOOMCase

cms gc 总结：  http://www.blogjava.net/killme2008/archive/2009/09/22/295931.html

http://www.oracle.com/technetwork/java/javase/index-137495.html

http://blog.codecentric.de/en/2010/01/java-outofmemoryerror-eine-tragodie-in-sieben-akten/

http://www.w3pop.com/learn/view/p/1/o/1/doc/linux_cmd_top/