JVM性能优化指南

JVM常用命令

• jps

The jps command lists the instrumented Java HotSpot VMs on the target system. The command is limited to reporting information on JVMs for which it has the access permissions.

• jinfo

The jinfo command prints Java configuration information for a specified Java process or core file or a remote debug server. The configuration information includes Java system properties and Java Virtual Machine (JVM) command-line flags.

jinfo -flag MaxHeapSize PID 
jinfo -flag UseG1GC PID

jinfo -flag [+|-] PID
jinfo -flag <name>=<value> PID

jinfo -flags PID

• jstat

The jstat command displays performance statistics for an instrumented Java HotSpot VM. The target JVM is identified by its virtual machine identifier, or vmid option.

jstat -class PID 1000 10   查看某个java进程的类装载信息，每1000毫秒输出一次，共输出10次

jstat -gc PID 1000 10

• jstack

The jstack command prints Java stack traces of Java threads for a specified Java process, core file, or remote debug server.

jstack PID

知识来源：马士兵教育