java start options

java 启动参数　

1. OOME 时生成堆 dump

     -XX:+HeapDumpOnOutOfMemoryError 
   

2. jdwp 协议 远程调试模式

    -agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=9999
       #### 早期版本
     -Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=9999
   

3. **常用分析工具
   1. ha heap analysis
   2. jca java core analysis
   3. ga gc log analysis