Arthas-Java 问题定位的终极利器-火焰图

旧城等待， 2022-11-10 14:19 719阅读 0赞

##### 前提 #####

> 提前安装 Arthas

##### profiler 命令生成火焰图 #####

profiler 命令原理使用 async-profiler 生成火焰图  
profiler 命令支持生成应用热点的火焰图。本质上是通过不断的采样，然后把收集到的采样结果生成火焰图。  
profiler 命令基本运行结构是 profiler action \[actionArg\]  
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查看所有支持的 action：

[arthas@9737]$ profiler actions
    Supported Actions: [resume, dumpCollapsed, getSamples, start, list, execute, version, stop, load, dumpFlat, actions, dumpTraces, status]
    [arthas@9737]$

查看版本:

[arthas@9737]$ profiler version
    1.8.3
    [arthas@9737]$

启动 profiler:

[arthas@9737]$ profiler start
    Started [cpu] profiling
    [arthas@9737]$

> 默认情况下，生成的是cpu的火焰图

获取已采集的 sample 的数量:

[arthas@9737]$  profiler getSamples
    12
    [arthas@9737]

查看 profiler 状态:  
可以查看当前 profiler 在采样哪种 event 和采样时间。

[arthas@9737]$ profiler status
    [perf] profiling is running for 166 seconds
    [arthas@9737]$

停止 profiler 生成 svg 格式结果

[arthas@9737]$  profiler stop
    OK
    profiler output file: /root/arthas-output/20210318-190449.svg
    [arthas@9737]$

通过浏览器查看 arthas-output 下面的 profiler 结果:  
默认情况下，arthas 使用 8563 http端口，则可以打开： http://192.168.189.131:8563/arthas-output/ 目录下面的profiler 结果：  
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profiler支持的events:  
在不同的平台，不同的OS下面，支持的events各有不同

[arthas@9737]$ profiler list
    Basic events:
      cpu
      alloc
      lock
      wall
      itimer
    Java method calls:
      ClassName.methodName
    Perf events:
      page-faults
      context-switches
      cycles
      instructions
      cache-references
      cache-misses
      branches
      branch-misses
      bus-cycles
      L1-dcache-load-misses
      LLC-load-misses
      dTLB-load-misses
      mem:breakpoint
      trace:tracepoint
    [arthas@9737]$

[img-0gKEfUp8-1616066736197_http_10.152.160.36_server_index.php_s_api_attachment_visitFile_sign_e4e8e6d0f58099e067e57e0ac998c491_showdoc_.jpg]: /images/20221022/6b2a12c369114888a1030b962365800a.png
[img-Ikckpaz4-1616066736209_http_10.152.160.36_server_index.php_s_api_attachment_visitFile_sign_6916c0acac813d1edcc241a52efacb7c_showdoc_.jpg]: https://img-blog.csdnimg.cn/20210318192659134.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMxNTU1OTUx,size_16,color_FFFFFF,t_70
[img-LhtHEWw8-1616066736210_http_10.152.160.36_server_index.php_s_api_attachment_visitFile_sign_ad148243fe1ab5188722b9b4353681d5_showdoc_.jpg]: https://img-blog.csdnimg.cn/20210318192730264.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMxNTU1OTUx,size_16,color_FFFFFF,t_70