2019年08月19日(星期一)  农历:己亥年七月十九
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  • 使用java自带工具监控jvm运行状态

作者:三年。分类: JAVA

1.jps:查看当前运行着的java进程(仿linux下的ps),显示进程号

2. jinfo: 查参数jinfo -flagPermSize 2208(进程号)

jinfo -flag MaxPermSize 2208(进程号)

C:\Users\WILL>jinfo

Usage:

jinfo <option> <pid>

(to connect to a running process)

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

-h | -help           to print this help message

3. jconsole 2208

用法:

jconsole [ -interval=n ] [ -notile ] [ -pluginpath <path> ] [ -version ] [ connection …]

-interval   将更新间隔时间设置为 n 秒(默认值为 4 秒)

-notile     最初不平铺显示窗口(对于两个或更多连接)

-pluginpath 指定 jconsole 用于查找插件的路径

-version    输出程序版本

connection = pid || host:port || JMX URL (service:jmx:<protocol>://…)

pid       目标进程的进程 ID

host      远程主机名或 IP 地址

port      用于远程连接的端口号

-J          对正在运行 jconsole 的 Java 虚拟机指定

输入参数

4. jstack  2208列出所有线程,以及线程的运行状态

C:\Users\WILL>jstack

Usage:

jstack [-l] <pid>

(to connect to running process)

Options:

-l  long listing. Prints additional information about locks

-h or -help to print this help message

5. jstat -gcutil 2208 1000(每隔1000毫秒打印一次信息) 10(打印10行)

C:\Users\WILL>jstat

invalid argument count

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.

C:\Users\WILL>jstat -options

-class

-compiler

-gc

-gccapacity

-gccause

-gcnew

-gcnewcapacity

-gcold

-gcoldcapacity

-gcpermcapacity

-gcutil

-printcompilation


6. jmap把虚拟机里运行着的所有文件都down下来,相当于快照

C:\Users\WILL>jmap

Usage:

jmap -histo <pid>

(to connect to running process and print histogram of java object heap

jmap -dump:<dump-options> <pid>

(to connect to running process and dump java heap)

dump-options:

format=b     binary default

file=<file>  dump heap to <file>

Example:       jmap -dump:format=b,file=heap.bin <pid>

7. jhat 对jmap下来的文件进行分析,多个角度

Usage:  jhat [-stack <bool>] [-refs <bool>] [-port <port>] [-baseline <file>] [-

debug <int>] [-version] [-h|-help] <file>

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

example, -J-mx512m to use a maximum heap size of 512MB

-stack false:     Turn off tracking object allocation call stack.

-refs false:      Turn off tracking of references to objects

-port <port>:     Set the port for the HTTP server.  Defaults to 7000

-exclude <file>:  Specify a file that lists data members that should

be excluded from the reachableFrom query.

-baseline <file>: Specify a baseline object dump.  Objects in

both heap dumps with the same ID and same class will

be marked as not being "new".

-debug <int>:     Set debug level.

0:  No debug output

1:  Debug hprof file parsing

2:  Debug hprof file parsing, no server

-version          Report version number

-h|-help          Print this help and exit

<file>            The file to read

For a dump file that contains multiple heap dumps,

you may specify which dump in the file

by appending "#<number>" to the file name, i.e. "foo.hprof#3".

All boolean options default to "true"

图片又不能上传…就打印出这些帮助参数来,能看懂得了。

温馨提示如有转载或引用以上内容之必要,敬请将本文链接作为出处标注,谢谢合作!

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