JDK的几种分析工具

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"
jhat filename.bin //就可以分析产生的dump文件，可以通过访问http://localhost:7000
IBM的堆分析工具HeapAnalyzer （http://www.alphaworks.ibm.com/tech/heapanalyzer ）。堆的dump log的视图化查看工具。
TDA - Thread Dump Analyzer (https://tda.dev.java.net/ )。线程dump的视图化查看工具。