man jstat

lester@lester-ThinkPad-T410:~/develop/jdk1.6.0_37/bin$ man jstat

jstat(1)                                                                                                          jstat(1)

Name
       jstat - Java Virtual Machine Statistics[n. 统计；统计学；[统计] 统计资料] Monitoring[n. 监视，[自] 监控；检验，检查] Tool

SYNOPSIS[n. 概要，大纲]
       jstat [ generalOption | outputOptions vmid [interval[s|ms] [count]] ]


PARAMETERS
          generalOption
             A single general command-line option (-help, -options, or -version)

          outputOptions
             One or more output options, consisting of[包含…；组成元素为…] a single statOption, plus any of the -t, -h, and -J options.

          vmid
             Virtual machine identifier[ 标志符], a string indicating[表明；指示] the target Java virtual machine (JVM). The general syntax[n. 语法；句法；有秩序的排列] is
             [protocol:][//]lvmid[@hostname[:port]/servername]
             The  syntax  of  the  vmid string largely corresponds[符合，一致；相应；通信] to the syntax of a URI. The vmid can vary[变化；变异；违反] from a simple
             integer representing a local JVM to a more complex construction[结构] specifying a  communications  protocol,  port
             number, and other implementation-specific values. See Virtual Machine Identifier for details.

          interval[s|ms]
             Sampling[取样；抽样]  interval in the specified units, seconds (s) or milliseconds (ms). Default units are milliseconds.
             Must be a positive[正数] integer.  If specified, jstat will produce its output at each interval.

          count
             Number of samples to display. Default value is infinity[无穷；无限大；无限距]; that is, jstat displays statistics until the  target
             JVM terminates[ 终止] or the jstat command is terminated.  Must be a positive integer.


DESCRIPTION
       The  jstat  tool displays performance[ 性能] statistics for an instrumented HotSpot Java virtual machine (JVM). The target
       JVM is identified by its virtual machine identifier, or vmid option described below.

       NOTE: This utility[可用性] is unsupported and may not be available in future versions of  the  JDK.  It  is  not  currently
       available on Windows 98 and Windows ME. platforms.


   VIRTUAL MACHINE IDENTIFIER
          The syntax[语法；句法；有秩序的排列] of the vmid string largely corresponds[符合，一致；相应；通信] to the syntax of a URI:

          [protocol:][//]lvmid[@hostname][:port][/servername]


             protocol
                The  communications protocol. If the protocol is omitted and a hostname is not specified, the default pro‐
                tocol is a platform specific optimized[最优] local protocol. If the protocol is omitted and a hostname is speci‐
                fied, then the default protocol is rmi.

             lvmid
                The  local  virtual  machine  identifier  for  the target JVM. The lvmid is a platform-specific value that
                uniquely[独特的] identifies a JVM on a system. The lvmid is the only required component of a virtual machine iden‐
                tifier.  The  lvmid  is  typically, but not necessarily, the operating system's process identifier for the
                target JVM process. You can use the jps(1) command to determine the lvmid. Also, you can  determine  lvmid
                on Unix platforms with the ps command, and on Windows with the Windows Task Manager.

             hostname
                A  hostname  or IP address indicating[表明，指示] the target host. If hostname is omitted[省略，省去的], then the target host is the
                local host.

             port
                The default port for communicating with the remote server. If the hostname  is  omitted  or  the  protocol
                specifies  an  optimized, local protocol, then port is ignored. Otherwise, treatment of the port parameter
                is implementation specific. For the default rmi protocol, the port  indicates[表明，指示，显示]  the  port  number  for  the
                rmiregistry  on  the remote host. If port is omitted, and protocol indicates rmi, then the default rmireg‐
                istry port (1099) is used.

             servername
                The treatment[处置] of this parameter depends on implementation. For the optimized[最优] local protocol, this field is
                ignored. For the rmi protocol, it represents the name of the RMI remote object on the remote host.


OPTIONS
       The jstat command supports two types of options, general options and output options. General options cause jstat to
       display simple usage[使用；用法；惯例] and version information. Output options determine the content and format  of  the  statistical
       output.


       NOTE: All options, and their functionality are subject to change or removal in future releases.

   GENERAL OPTIONS
       If you specify one of the general options, you cannot specify any other option or parameter.

          -help
             Display help message.

          -version
             Display version information.

          -options
             Display list of statistics[n. 统计；统计学；[统计] 统计资料] options. See the Output Options section below.


   OUTPUT OPTIONS
          If  you  do not specify a general option, then you can specify output options. Output options determine the con‐
          tent and format of jstat's output, and consist of a single statOption, plus any of the other output options (-h,
          -t, and -J).  The statOption must come first.

          Output  is  formatted  as  a table, with columns are separated by spaces. A header row with titles describes the
          columns.  Use the -h option to set the frequency[频率] at which the header is displayed.  Column header names are gen‐
          erally consistent[始终如一的，一致的；坚持的] between the different options. In general, if two options provide a column with the same name,
          then the data source for the two columns are the same.

          Use the -t option to display a time stamp[印记；标志] column, labeled Timestamp as the first column of output. The Timestamp
          column  contains the elapsed[时间过去；消逝] time, in seconds, since startup of the target JVM. The resolution[ 解析度] of the time stamp
          is dependent[依靠的，从属的，取决于] on various factors and is subject[主题，科目] to variation[ 可变性] due to[由于] delayed thread scheduling on  heavily  loaded
          systems.

          Use  the  interval and count parameters to determine[确定] how frequently and how many times, respectively[分别地；各自地，独自地], jstat dis‐
          plays its output.

          NOTE: You are advised not to write scripts to parse jstat's  output  since  the  format  may  change  in  future
          releases.  If  you choose to write scripts that parse jstat output, expect to modify them for future releases of
          this tool.

             -statOption
                Determines the statistics information that  jstat  displays.  The  following  table  lists  the  available
                options.  Use the -options general option to display the list of options for a particular platform instal‐
                lation.

             -h n
                Display a column header every n samples (output rows), where n is a positive[正的] integer. Default value is  0,
                which displays the column header above the first row of data.

             -t n
                Display  a  timestamp column as the first column of output. The timestamp is the time since the start time
                of the target JVM.

             -JjavaOption
                Pass javaOption to the java application launcher. For example, -J-Xms48m sets the  startup  memory  to  48
                megabytes. For a complete list of options, see java(1)


   STATOPTIONS AND OUTPUT
          The following tables summarize the columns that jstat outputs for each statOption.

   -class Option

    lester@lester-ThinkPad-T410:~/develop/jdk1.6.0_37/bin$ jstat -class -h10 3007 1s
    Loaded          Bytes  Unloaded  Bytes     Time   
    9567            12506.2        0           0.0      13.96
    9567            12506.2        0           0.0      13.96
    9567            12506.2        0           0.0      13.96
    9567            12506.2        0           0.0      13.96
    9567            12506.2        0           0.0      13.96

   -compiler Option

    lester@lester-ThinkPad-T410:~/develop/jdk1.6.0_37/bin$ jstat -compiler -h10 3007 1s
    Compiled Failed Invalid   Time   FailedType FailedMethod
    3007             0       0     2.77          0             
    3007             0       0     2.77          0             
    3007             0       0     2.77          0             
    3007             0       0     2.77          0             
    3007             0       0     2.77          0             
    3007             0       0     2.77          0             
    3007             0       0     2.77          0

   -gc Option

     lester@lester-ThinkPad-T410:~/develop/jdk1.6.0_37/bin$ jstat -gc -h10 3007 1s
 S0C         S1C       S0U    S1U      EC          EU             OC              OU            PC             PU              YGC YGCT FGC FGCT     GCT   
17472.0 17472.0 7343.4  0.0   139776.0 137784.5  349568.0   29540.3   524288.0 53285.3     12    0.891   0      0.000    0.891
17472.0 17472.0 7343.4  0.0   139776.0 137784.5  349568.0   29540.3   524288.0 53285.3     12    0.891   0      0.000    0.891
17472.0 17472.0 7343.4  0.0   139776.0 139776.0  349568.0   29540.3   524288.0 53285.3     12    0.891   0      0.000    0.891
17472.0 17472.0 7343.4  0.0   139776.0 139776.0  349568.0   29540.3   524288.0 53285.3     12    0.891   0      0.000    0.891
17472.0 17472.0  0.0   7367.6 139776.0  2855.2   349568.0   29540.3   524288.0 53285.3     13    0.918   0      0.000    0.918
17472.0 17472.0  0.0   7367.6 139776.0  2855.2   349568.0   29540.3   524288.0 53285.3     13    0.918   0      0.000    0.918
17472.0 17472.0  0.0   7367.6 139776.0  2879.2   349568.0   29540.3   524288.0 53285.3     13    0.918   0      0.000    0.918

   -gccapacity Option

lester@lester-ThinkPad-T410:~/develop/jdk1.6.0_37/bin$ jstat -gccapacity -h10 3007 1s
 NGCMN    NGCMX     NGC     S0C   S1C       EC      OGCMN      OGCMX       OGC         OC      PGCMN    PGCMX     PGC       PC     YGC    FGC
174720.0 174720.0 174720.0 17472.0 17472.0 139776.0   349568.0   349568.0   349568.0   349568.0 524288.0 524288.0 524288.0 524288.0     13     0
174720.0 174720.0 174720.0 17472.0 17472.0 139776.0   349568.0   349568.0   349568.0   349568.0 524288.0 524288.0 524288.0 524288.0     13     0
174720.0 174720.0 174720.0 17472.0 17472.0 139776.0   349568.0   349568.0   349568.0   349568.0 524288.0 524288.0 524288.0 524288.0     13     0
174720.0 174720.0 174720.0 17472.0 17472.0 139776.0   349568.0   349568.0   349568.0   349568.0 524288.0 524288.0 524288.0 524288.0     13     0
174720.0 174720.0 174720.0 17472.0 17472.0 139776.0   349568.0   349568.0   349568.0   349568.0 524288.0 524288.0 524288.0 524288.0     13     0

   -gccause Option
       This  option  displays  the  same  summary of garbage collection statistics as the -gcutil option, but includes the
       causes of the last garbage collection event and (if applicable) the current garbage collection event.  In  addition

       to the columns listed for -gcutil, this option adds the following columns:

        lester@lester-ThinkPad-T410:~/develop/jdk1.6.0_37/bin$ jstat -gccause -h10 3007 1s
  S0     S1     E      O      P     YGC     YGCT    FGC    FGCT     GCT    LGCC                 GCC                 
  0.00  42.17  55.08   8.45  10.16     13    0.918     0    0.000    0.918 unknown GCCause      No GC               
  0.00  42.17  55.08   8.45  10.16     13    0.918     0    0.000    0.918 unknown GCCause      No GC               
  0.00  42.17  55.09   8.45  10.16     13    0.918     0    0.000    0.918 unknown GCCause      No GC               
  0.00  42.17  55.10   8.45  10.16     13    0.918     0    0.000    0.918 unknown GCCause      No GC               
  0.00  42.17  55.10   8.45  10.16     13    0.918     0    0.000    0.918 unknown GCCause      No GC               
  0.00  42.17  55.10   8.45  10.16     13    0.918     0    0.000    0.918 unknown GCCause      No GC               
  0.00  42.17  55.10   8.45  10.16     13    0.918     0    0.000    0.918 unknown GCCause      No GC               
  0.00  42.17  57.03   8.45  10.16     13    0.918     0    0.000    0.918 unknown GCCause      No GC               
  0.00  42.17  57.03   8.45  10.16     13    0.918     0    0.000    0.918 unknown GCCause      No GC               
  0.00  42.17  57.05   8.45  10.16     13    0.918     0    0.000    0.918 unknown GCCause      No GC               
  S0     S1     E      O      P     YGC     YGCT    FGC    FGCT     GCT    LGCC                 GCC 

   -gcnew Option

    lester@lester-ThinkPad-T410:~/develop/jdk1.6.0_37/bin$ jstat -gcnew -h10 3007 1s
 S0C    S1C    S0U    S1U   TT MTT  DSS      EC       EU     YGC     YGCT  
17472.0 17472.0    0.0 7367.6 15  15 8736.0 139776.0  94172.7     13    0.918
17472.0 17472.0    0.0 7367.6 15  15 8736.0 139776.0  94172.7     13    0.918
17472.0 17472.0    0.0 7367.6 15  15 8736.0 139776.0  94181.5     13    0.918
17472.0 17472.0    0.0 7367.6 15  15 8736.0 139776.0  94181.5     13    0.918
17472.0 17472.0    0.0 7367.6 15  15 8736.0 139776.0  94181.5     13    0.918

   -gcnewcapacity Option

    lester@lester-ThinkPad-T410:~/develop/jdk1.6.0_37/bin$ jstat -gcnewcapacity -h10 3007 1s
  NGCMN      NGCMX       NGC      S0CMX     S0C     S1CMX     S1C       ECMX        EC      YGC   FGC
  174720.0   174720.0   174720.0  17472.0  17472.0  17472.0  17472.0   139776.0   139776.0    13     0
  174720.0   174720.0   174720.0  17472.0  17472.0  17472.0  17472.0   139776.0   139776.0    13     0
  174720.0   174720.0   174720.0  17472.0  17472.0  17472.0  17472.0   139776.0   139776.0    13     0
  174720.0   174720.0   174720.0  17472.0  17472.0  17472.0  17472.0   139776.0   139776.0    13     0
  174720.0   174720.0   174720.0  17472.0  17472.0  17472.0  17472.0   139776.0   139776.0    13     0
  174720.0   174720.0   174720.0  17472.0  17472.0  17472.0  17472.0   139776.0   139776.0    13     0

   -gcold Option

    lester@lester-ThinkPad-T410:~/develop/jdk1.6.0_37/bin$ jstat -gcold -h10 3007 1s
   PC       PU        OC          OU       YGC    FGC    FGCT     GCT   
524288.0  53285.3    349568.0     29540.3     13     0    0.000    0.918
524288.0  53285.3    349568.0     29540.3     13     0    0.000    0.918
524288.0  53285.3    349568.0     29540.3     13     0    0.000    0.918
524288.0  53285.3    349568.0     29540.3     13     0    0.000    0.918

   -gcoldcapacity Option

    lester@lester-ThinkPad-T410:~/develop/jdk1.6.0_37/bin$ jstat -gcoldcapacity -h10 3007 1s
   OGCMN       OGCMX        OGC         OC       YGC   FGC    FGCT     GCT   
   349568.0    349568.0    349568.0    349568.0    13     0    0.000    0.918
   349568.0    349568.0    349568.0    349568.0    13     0    0.000    0.918
   349568.0    349568.0    349568.0    349568.0    13     0    0.000    0.918
   349568.0    349568.0    349568.0    349568.0    13     0    0.000    0.918
   349568.0    349568.0    349568.0    349568.0    13     0    0.000    0.918
   349568.0    349568.0    349568.0    349568.0    13     0    0.000    0.918
   349568.0    349568.0    349568.0    349568.0    13     0    0.000    0.918
   349568.0    349568.0    349568.0    349568.0    13     0    0.000    0.918

   -gcpermcapacity Option

    lester@lester-ThinkPad-T410:~/develop/jdk1.6.0_37/bin$ jstat -gcpermcapacity -h10 3007 1s
  PGCMN      PGCMX       PGC         PC      YGC   FGC    FGCT     GCT   
  524288.0   524288.0   524288.0   524288.0    13     0    0.000    0.918
  524288.0   524288.0   524288.0   524288.0    13     0    0.000    0.918
  524288.0   524288.0   524288.0   524288.0    13     0    0.000    0.918
  524288.0   524288.0   524288.0   524288.0    13     0    0.000    0.918
  524288.0   524288.0   524288.0   524288.0    13     0    0.000    0.918
  524288.0   524288.0   524288.0   524288.0    13     0    0.000    0.918
  524288.0   524288.0   524288.0   524288.0    13     0    0.000    0.918
  524288.0   524288.0   524288.0   524288.0    13     0    0.000    0.918
  524288.0   524288.0   524288.0   524288.0    13     0    0.000    0.918

   -gcutil Option

    lester@lester-ThinkPad-T410:~/develop/jdk1.6.0_37/bin$ jstat -gcutil -h10 3007 1s
  S0     S1     E      O      P     YGC     YGCT    FGC    FGCT     GCT   
 42.08   0.00   6.30   8.45  10.16     14    0.945     0    0.000    0.945
 42.08   0.00   6.31   8.45  10.16     14    0.945     0    0.000    0.945
 42.08   0.00   6.31   8.45  10.16     14    0.945     0    0.000    0.945
 42.08   0.00   6.52   8.45  10.16     14    0.945     0    0.000    0.945
 42.08   0.00   6.52   8.45  10.16     14    0.945     0    0.000    0.945
 42.08   0.00   6.55   8.45  10.16     14    0.945     0    0.000    0.945
 42.08   0.00   8.27   8.45  10.16     14    0.945     0    0.000    0.945

   -printcompilation Option

lester@lester-ThinkPad-T410:~/develop/jdk1.6.0_37/bin$ jstat -printcompilation -h10 3007 1s
Compiled  Size  Type Method
    3038     11    1 org/eclipse/ui/internal/console/IOConsolePartitioner$QueueProcessingJob runInUIThread
    3038     11    1 org/eclipse/ui/internal/console/IOConsolePartitioner$QueueProcessingJob runInUIThread
    3038     11    1 org/eclipse/ui/internal/console/IOConsolePartitioner$QueueProcessingJob runInUIThread
    3038     11    1 org/eclipse/ui/internal/console/IOConsolePartitioner$QueueProcessingJob runInUIThread
    3038     11    1 org/eclipse/ui/internal/console/IOConsolePartitioner$QueueProcessingJob runInUIThread
    3038     11    1 org/eclipse/ui/internal/console/IOConsolePartitioner$QueueProcessingJob runInUIThread
    3038     11    1 org/eclipse/ui/internal/console/IOConsolePartitioner$QueueProcessingJob runInUIThread

       This section presents some examples of monitoring a local JVM with a lvmid of 21891.

   Using the gcutil option
       This  example  attaches  to[附着于] lvmid 21891 and takes 7 samples at 250 millisecond intervals and displays the output as
       specified by the -gcutil option.

       jstat -gcutil 21891 250 7

         S0         S1        E      O      P     YGC    YGCT    FGC    FGCT     GCT

        12.44   0.00  27.20   9.49  96.70    78    0.176     5    0.495    0.672

        12.44   0.00  62.16   9.49  96.70    78    0.176     5    0.495    0.672

        12.44   0.00  83.97   9.49  96.70    78    0.176     5    0.495    0.672

         0.00    7.74   0.00     9.51  96.70    79    0.177     5    0.495    0.673

         0.00   7.74  23.37   9.51  96.70    79    0.177     5    0.495    0.673

         0.00   7.74  43.82   9.51  96.70    79    0.177     5    0.495    0.673

         0.00   7.74  58.11   9.51  96.71    79    0.177     5    0.495    0.673



       The output of this example shows that a young generation collection occurred between the 3rd and  4th  sample[取样；尝试；抽样检查].  The
       collection  took  0.001  seconds and promoted[晋升的] objects from the eden space (E) to the old space (O), resulting in an
       increase of old space utilization from 9.49% to 9.51%. Before the collection, the survivor space  was  12.44%  uti‐
       lized, but after this collection it is only 7.74% utilized[被利用的].

   Repeating the column header string
       This  example  attaches  to  lvmid  21891 and takes samples at 250 millisecond intervals and displays the output as
       specified by -gcutil option. In addition, it uses the -h3 option to output the column header after every 3 lines of
       data.

       jstat -gcnew -h3 21891 250

        S0C    S1C    S0U    S1U       TT   MTT  DSS      EC       EU       YGC     YGCT

         64.0   64.0    0.0      31.7        31   31     32.0    512.0    178.6    249    0.203

         64.0   64.0    0.0      31.7        31   31     32.0    512.0    355.5    249    0.203

         64.0   64.0   35.4     0.0          2     31     32.0    512.0     21.9    250    0.204

        S0C    S1C    S0U    S1U      TT   MTT  DSS      EC        EU       YGC     YGCT

         64.0   64.0   35.4    0.0           2     31     32.0    512.0    245.9    250    0.204

         64.0   64.0   35.4    0.0           2     31     32.0    512.0    421.1    250    0.204

         64.0   64.0    0.0    19.0         31    31     32.0    512.0     84.4    251    0.204

        S0C    S1C    S0U    S1U      TT   MTT  DSS      EC       EU     YGC     YGCT

         64.0   64.0    0.0   19.0          31  31      32.0    512.0    306.7    251    0.204



       In  addition  to  showing  the  repeating header string, this example shows that between the 2nd and 3rd samples, a
       young GC occurred. Its duration was 0.001 seconds. The collection found enough live data that the survivor space  0
       utilization[利用，使用]  (S0U) would would have exceeded[超过（exceed的过去分词）；越出] the desired[渴望的；想得到的] survivor Size (DSS). As a result, objects were promoted to the old generation (not visible[ 可见的] in this output), and the tenuring[ 占有期；保有期] threshold[ 阈值] (TT) was lowered from 31 to 2.

       Another collection occurs between the 5th and 6th samples. This collection found very few  survivors  and  returned
       the tenuring threshold to 31.

   Including a time stamp for each sample
       This  example  attaches  to  lvmid 21891 and takes 3 samples at 250 millisecond intervals. The -t option is used to
       generate a time stamp for each sample in the first column.

       jstat -gcoldcapacity -t 21891 250 3

       Timestamp          OGCMN        OGCMX         OGC           OC       YGC   FGC    FGCT    GCT

                 150.1           1408.0      60544.0         11696.0      11696.0   194    80    2.874   3.799

                 150.4           1408.0      60544.0         13820.0      13820.0   194    81    2.938   3.863

                 150.7           1408.0      60544.0         13820.0      13820.0   194    81    2.938   3.863



       The Timestamp column reports the elapsed time in seconds since the start  of  the  target  JVM.  In  addition,  the
       -gcoldcapacity  output  shows  the  old generation capacity (OGC) and the old space capacity (OC) increasing as the
       heap expands to meet allocation[分配，配置；安置] and/or promotion demands[需求]. The old generation capacity (OGC) has grown to from 11696
       KB  to  13820  KB  after  the  81st  Full  GC (FGC). The maximum capacity of the generation (and space) is 60544 KB
       (OGCMX), so it still has room to expand.

       Monitor[监控] instrumentation[ 方法] for a remote JVM
       This example attaches to lvmid 40496 on the system named remote.domain using the -gcutil option, with samples taken
       every second indefinitely.

       jstat -gcutil 40496@remote.domain 1000




       The  lvmid  is  combined[结合的，组合的]  with  the  name  of the remote host to construct a vmid of 40496@remote.domain. This vmid
       results in the use of the rmi protocol to communicate to the default jstatd server on the remote host.  The  jstatd
       server is located using the rmiregistry on remote.domain that is bound to the default rmiregistry port (port 1099).

SEE ALSO
          o java(1) - the Java Application Launcher

          o jps(1) - the Java Process Status Application

          o jstatd(1) - the jvmstat daemon

          o rmiregistry(1) - the Java Remote Object Registry