Usage: jstat --help|-options

       jstat -<option> [-t] [-h<lines>] <vmid> [<interval> [<count>]]

Definitions:

  <option>      An option reported by the -options option

  <vmid>        Virtual Machine Identifier. A vmid takes the following form:

                     <lvmid>[@<hostname>[:<port>]]

                Where <lvmid> is the local vm identifier for the target

                Java virtual machine, typically a process id; <hostname> is

                the name of the host running the target Java virtual machine;

                and <port> is the port number for the rmiregistry on the

                target host. See the jvmstat documentation for a more complete

                description of the Virtual Machine Identifier.

  <lines>       Number of samples between header lines.

  <interval>    Sampling interval. The following forms are allowed:

                    <n>["ms"|"s"]

                Where <n> is an integer and the suffix specifies the units as

                milliseconds("ms") or seconds("s"). The default units are "ms".

  <count>       Number of samples to take before terminating.

  -J<flag>      Pass <flag> directly to the runtime system.

  -? -h --help  Prints this help message.

  -help         Prints this help message.

-class             // 显示类加载信息

-compiler          // 显示编译信息

-gc                // 显示GC相关信息

-gccapacity        // 显示各区域容量及使用情况

-gccause           // 显示垃圾回收信息

-gcmetacapacity    // 显示元空间容量信息

-gcnew             // 显示新生代信息

-gcnewcapacity     // 显示新生代容量信息

-gcold             // 显示老年代信息

-gcoldcapacity     // 显示老年代容量信息

-gcutil            // 显示垃圾收集信息

-printcompilation  // 显示JIT编译的方法信息

jstat -gcutil 20272 2s 3