JDK的几种分析工具

最新推荐文章于 2024-04-25 23:48:15 发布

guo_yang

最新推荐文章于 2024-04-25 23:48:15 发布

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本文链接：https://blog.youkuaiyun.com/guo_yang/article/details/82186420

From： http://blog.youkuaiyun.com/hantiannan/archive/2009/10/10/4651617.aspx

学习了一下JDK中的一些自带系统性能分析工具。

在jdk的bin目录下，jconsole，jstack、jmap、jstat、jhat

jconsole 是监视和管理工具。可以查看堆内存，线程，类，CPU状况。直接双击就可以启动了，然后选择连接本地local还是远程remote，分析结果就出现在界面上了。当然也可以从命令行启动界面。

jstack 主要用于线程死锁的监控。

命令行中输入jstack -h查看用法

C:\Program Files (x86)\Java\jdk1.6.0_14\bin>jstack -h
Usage:
??? jstack [-l] <pid>
??????? (to connect to running process)
Options:
??? -l? long listing. Prints additional infor
??? -h or -help to print this help message

pid 进程号

jmap 主要用于监控内存泄露时候对象占用的字节数。

命令行中输入jmap -h查看用法

C:\Program Files (x86)\Java\jdk1.6.0_14\bin>jmap -h
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>

jstat 主要用于监控jvm的gc使用情况。

命令行中输入jstat -h查看用法

C:\Program Files (x86)\Java\jdk1.6.0_14\bin>jstat -h
-h requires an integer argument
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.

pid 进程号，interval时间间隔，count次数

jhat 主要用于分析jmap产生的dump并提供web页面查看分析结果。

命令行中输入jhat -h查看用法

C:\Program Files (x86)\Java\jdk1.6.0_14\bin>jhat -h
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"