JVM工具jinfo实践

一、jinfo命令格式

命令格式：

jinfo [option] <pid>

Usage:
    jinfo [option] <pid>
        (to connect to running process)
    jinfo [option] <executable <core>
        (to connect to a core file)
    jinfo [option] [server_id@]<remote server IP or hostname>
        (to connect to remote debug server)

where <option> is one of:
    -flag <name>         to print the value of the named VM flag
    -flag [+|-]<name>    to enable or disable the named VM flag
    -flag <name>=<value> to set the named VM flag to the given value
    -flags               to print VM flags
    -sysprops            to print Java system properties
    <no option>          to print both of the above
    -h | -help           to print this help message

二、打印所有参数

 jinfo -flags [pid]

三、查看某个参数

四、动态修改参数

1、禁用（不过该参数不能修改）

2、启用（也遇到了不能改的）

3、来个可改的

五、查看系统属性