JDK的幾種分析工具

CevenCheng 2011-08-05

展開全文

學(xué)習(xí)了一下JDK中的一些自帶系統(tǒng)性能分析工具。

在jdk的bin目錄下，jconsole，jstack、jmap、jstat、jhat

jconsole 是監(jiān)視和管理工具?？梢圆榭炊褍?nèi)存，線程，類，CPU狀況。直接雙擊就可以啟動了，然后選擇連接本地local還是遠程remote，分析結(jié)果就出現(xiàn)在界面上了。當(dāng)然也可以從命令行啟動界面。

jstack 主要用于線程死鎖的監(jiān)控。

命令行中輸入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 進程號

jmap 主要用于監(jiān)控內(nèi)存泄露時候?qū)ο笳加玫淖止?jié)數(shù)。

命令行中輸入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 主要用于監(jiān)控jvm的gc使用情況。

命令行中輸入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 進程號，interval時間間隔，count次數(shù)

jhat 主要用于分析jmap產(chǎn)生的dump并提供web頁面查看分析結(jié)果。

命令行中輸入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"