<!DOCTYPE html>
<!--[if IE 8]><html class="no-js lt-ie9" lang="zh-CN" > <![endif]-->
<!--[if gt IE 8]><!--> <html class="no-js" lang="zh-CN" > <!--<![endif]-->
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>trace — Arthas 3.0.6-SNAPSHOT 文档</title>
<link rel="shortcut icon" href="_static/favicon.ico"/>
<link rel="stylesheet" href="_static/css/theme.css" type="text/css" />
<link rel="stylesheet" href="_static/pygments.css" type="text/css" />
<link rel="stylesheet" href="_static/overrides.css" type="text/css" />
<link rel="index" title="索引" href="genindex.html" />
<link rel="search" title="搜索" href="search.html" />
<link rel="next" title="stack" href="stack.html" />
<link rel="prev" title="watch" href="watch.html" />
<script src="_static/center_page.js"></script>
<script src="_static/js/modernizr.min.js"></script>
</head>
<body class="wy-body-for-nav">
<div class="wy-grid-for-nav">
<nav data-toggle="wy-nav-shift" class="wy-nav-side">
<div class="wy-side-scroll">
<div class="wy-side-nav-search">
<a href="index.html" class="icon icon-home"> Arthas
</a>
<div class="version">
3.0.6-SNAPSHOT
</div>
<div role="search">
<form id="rtd-search-form" class="wy-form" action="search.html" method="get">
<input type="text" name="q" placeholder="Search docs" />
<input type="hidden" name="check_keywords" value="yes" />
<input type="hidden" name="area" value="default" />
</form>
</div>
</div>
<div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="main navigation">
<ul class="current">
<li class="toctree-l1"><a class="reference external" href="https://alibaba.github.io/arthas/en/">English Docs</a></li>
<li class="toctree-l1"><a class="reference internal" href="install-detail.html">安装</a></li>
<li class="toctree-l1"><a class="reference internal" href="quick-start.html">快速入门</a></li>
<li class="toctree-l1"><a class="reference internal" href="advanced-use.html">进阶使用</a></li>
<li class="toctree-l1 current"><a class="reference internal" href="commands.html">命令列表</a><ul class="current">
<li class="toctree-l2"><a class="reference internal" href="dashboard.html">dashboard</a></li>
<li class="toctree-l2"><a class="reference internal" href="thread.html">thread</a></li>
<li class="toctree-l2"><a class="reference internal" href="jvm.html">jvm</a></li>
<li class="toctree-l2"><a class="reference internal" href="sysprop.html">sysprop</a></li>
<li class="toctree-l2"><a class="reference internal" href="sysenv.html">sysenv</a></li>
<li class="toctree-l2"><a class="reference internal" href="getstatic.html">getstatic</a></li>
<li class="toctree-l2"><a class="reference internal" href="ognl.html">ognl</a></li>
<li class="toctree-l2"><a class="reference internal" href="sc.html">sc</a></li>
<li class="toctree-l2"><a class="reference internal" href="sm.html">sm</a></li>
<li class="toctree-l2"><a class="reference internal" href="dump.html">dump</a></li>
<li class="toctree-l2"><a class="reference internal" href="jad.html">jad</a></li>
<li class="toctree-l2"><a class="reference internal" href="classloader.html">classloader</a></li>
<li class="toctree-l2"><a class="reference internal" href="redefine.html">redefine</a></li>
<li class="toctree-l2"><a class="reference internal" href="monitor.html">monitor</a></li>
<li class="toctree-l2"><a class="reference internal" href="watch.html">watch</a></li>
<li class="toctree-l2 current"><a class="current reference internal" href="#">trace</a><ul>
<li class="toctree-l3"><a class="reference internal" href="#">参数说明</a></li>
<li class="toctree-l3"><a class="reference internal" href="#">注意事项</a></li>
<li class="toctree-l3"><a class="reference internal" href="#">使用参考</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="stack.html">stack</a></li>
<li class="toctree-l2"><a class="reference internal" href="tt.html">tt</a></li>
<li class="toctree-l2"><a class="reference internal" href="options.html">options</a></li>
<li class="toctree-l2"><a class="reference internal" href="commands.html#arthas">Arthas 基础命令</a></li>
</ul>
</li>
<li class="toctree-l1"><a class="reference external" href="https://github.com/alibaba/arthas/issues?q=label%3Auser-case">用户案例</a></li>
<li class="toctree-l1"><a class="reference external" href="https://github.com/alibaba/arthas/issues?q=label%3Aquestion-answered">Questions and answers</a></li>
<li class="toctree-l1"><a class="reference external" href="https://github.com/alibaba/arthas">Fork me at GitHub</a></li>
<li class="toctree-l1"><a class="reference external" href="https://github.com/alibaba/arthas/blob/master/CONTRIBUTING.md">参与贡献</a></li>
<li class="toctree-l1"><a class="reference internal" href="release-notes.html">Release Notes</a></li>
</ul>
</div>
</div>
</nav>
<section data-toggle="wy-nav-shift" class="wy-nav-content-wrap">
<nav class="wy-nav-top" aria-label="top navigation">
<i data-toggle="wy-nav-top" class="fa fa-bars"></i>
<a href="index.html">Arthas</a>
</nav>
<div class="wy-nav-content">
<div class="rst-content">
<div role="navigation" aria-label="breadcrumbs navigation">
<ul class="wy-breadcrumbs">
<li><a href="index.html">Docs</a> »</li>
<li><a href="commands.html">命令列表</a> »</li>
<li>trace</li>
<li class="wy-breadcrumbs-aside">
<a href="https://github.com/alibaba/arthas/blob/master/site/src/site/sphinx/trace.md" class="fa fa-github"> Edit on GitHub</a>
</li>
</ul>
<hr/>
</div>
<div role="main" class="document" itemscope="itemscope" itemtype="http://schema.org/Article">
<div itemprop="articleBody">
<div class="section" id="trace">
<span id="trace"></span><h1>trace<a class="headerlink" href="#trace" title="永久链接至标题">¶</a></h1>
<blockquote>
<div>方法内部调用路径，并输出方法路径上的每个节点上耗时</div></blockquote>
<p><code class="docutils literal notranslate"><span class="pre">trace</span></code> 命令能主动搜索 <code class="docutils literal notranslate"><span class="pre">class-pattern</span></code>／<code class="docutils literal notranslate"><span class="pre">method-pattern</span></code> 对应的方法调用路径，渲染和统计整个调用链路上的所有性能开销和追踪调用链路。</p>
<div class="section" id="">
<span id="id1"></span><h2>参数说明<a class="headerlink" href="#" title="永久链接至标题">¶</a></h2>
<table border="1" class="docutils">
<thead>
<tr>
<th align="right">参数名称</th>
<th align="left">参数说明</th>
</tr>
</thead>
<tbody>
<tr>
<td align="right"><em>class-pattern</em></td>
<td align="left">类名表达式匹配</td>
</tr>
<tr>
<td align="right"><em>method-pattern</em></td>
<td align="left">方法名表达式匹配</td>
</tr>
<tr>
<td align="right"><em>condition-express</em></td>
<td align="left">条件表达式</td>
</tr>
<tr>
<td align="right">[E]</td>
<td align="left">开启正则表达式匹配，默认为通配符匹配</td>
</tr>
<tr>
<td align="right"><code>[n:]</code></td>
<td align="left">命令执行次数</td>
</tr>
<tr>
<td align="right"><code>#cost</code></td>
<td align="left">方法执行耗时</td>
</tr>
</tbody>
</table><p>这里重点要说明的是观察表达式，观察表达式的构成主要由 ognl 表达式组成，所以你可以这样写<code class="docutils literal notranslate"><span class="pre">"{params,returnObj}"</span></code>，只要是一个合法的 ognl 表达式，都能被正常支持。</p>
<p>观察的维度也比较多，主要体现在参数 <code class="docutils literal notranslate"><span class="pre">advice</span></code> 的数据结构上。<code class="docutils literal notranslate"><span class="pre">Advice</span></code> 参数最主要是封装了通知节点的所有信息。</p>
<p>请参考<a class="reference internal" href="advice-class.html"><span class="doc">表达式核心变量</span></a>中关于该节点的描述。</p>
<ul class="simple">
<li>特殊用法请参考：<a class="reference external" href="https://github.com/alibaba/arthas/issues/71">https://github.com/alibaba/arthas/issues/71</a></li>
<li>OGNL表达式官网：<a class="reference external" href="https://commons.apache.org/proper/commons-ognl/language-guide.html">https://commons.apache.org/proper/commons-ognl/language-guide.html</a></li>
</ul>
<p>很多时候我们只想看到某个方法的rt大于某个时间之后的trace结果，现在Arthas可以按照方法执行的耗时来进行过滤了，例如<code class="docutils literal notranslate"><span class="pre">trace</span> <span class="pre">*StringUtils</span> <span class="pre">isBlank</span> <span class="pre">'$cost>100'</span></code>表示当执行时间超过100ms的时候，才会输出trace的结果。</p>
<blockquote>
<div><p>注意：</p>
<ol class="simple">
<li>watch/stack/trace这个三个命令都支持$cost</li>
<li>如果是Arthas 3.0，请把<code class="docutils literal notranslate"><span class="pre">$cost</span></code>改为<code class="docutils literal notranslate"><span class="pre">#cost</span></code></li>
</ol>
</div></blockquote>
</div>
<div class="section" id="">
<span id="id2"></span><h2>注意事项<a class="headerlink" href="#" title="永久链接至标题">¶</a></h2>
<p><code class="docutils literal notranslate"><span class="pre">trace</span></code> 能方便的帮助你定位和发现因 RT 高而导致的性能问题缺陷，但其每次只能跟踪一级方法的调用链路。</p>
</div>
<div class="section" id="">
<span id="id3"></span><h2>使用参考<a class="headerlink" href="#" title="永久链接至标题">¶</a></h2>
<p>代码示例：</p>
<div class="highlight-java notranslate"><div class="highlight"><pre><span></span> <span class="kd">public</span> <span class="kd">static</span> <span class="kt">void</span> <span class="nf">main</span><span class="o">(</span><span class="n">String</span><span class="o">[]</span> <span class="n">args</span><span class="o">)</span> <span class="o">{</span>
<span class="n">List</span><span class="o"><</span><span class="n">String</span><span class="o">></span> <span class="n">list</span> <span class="o">=</span> <span class="k">new</span> <span class="n">ArrayList</span><span class="o"><</span><span class="n">String</span><span class="o">>();</span>
<span class="n">list</span><span class="o">.</span><span class="na">add</span><span class="o">(</span><span class="s">"a"</span><span class="o">);</span>
<span class="n">list</span><span class="o">.</span><span class="na">add</span><span class="o">(</span><span class="s">"b"</span><span class="o">);</span>
<span class="n">List</span><span class="o"><</span><span class="n">String</span><span class="o">></span> <span class="n">list2</span> <span class="o">=</span> <span class="k">new</span> <span class="n">ArrayList</span><span class="o"><</span><span class="n">String</span><span class="o">>();</span>
<span class="n">list2</span><span class="o">.</span><span class="na">add</span><span class="o">(</span><span class="s">"c"</span><span class="o">);</span>
<span class="n">list2</span><span class="o">.</span><span class="na">add</span><span class="o">(</span><span class="s">"d"</span><span class="o">);</span>
<span class="kt">int</span> <span class="n">len</span> <span class="o">=</span> <span class="n">add</span><span class="o">(</span><span class="n">list</span><span class="o">,</span> <span class="n">list2</span><span class="o">);</span>
<span class="o">}</span>
<span class="kd">private</span> <span class="kd">static</span> <span class="kt">int</span> <span class="nf">add</span><span class="o">(</span><span class="n">List</span><span class="o"><</span><span class="n">String</span><span class="o">></span> <span class="n">list</span><span class="o">,</span> <span class="n">List</span><span class="o"><</span><span class="n">String</span><span class="o">></span> <span class="n">list2</span><span class="o">)</span> <span class="o">{</span>
<span class="kt">int</span> <span class="n">i</span> <span class="o">=</span> <span class="mi">10</span><span class="o">;</span>
<span class="k">while</span> <span class="o">(</span><span class="n">i</span> <span class="o">>=</span> <span class="mi">0</span><span class="o">)</span> <span class="o">{</span>
<span class="k">try</span> <span class="o">{</span>
<span class="n">hehe</span><span class="o">(</span><span class="n">i</span><span class="o">);</span>
<span class="o">}</span> <span class="k">catch</span> <span class="o">(</span><span class="n">Throwable</span> <span class="n">t</span><span class="o">)</span> <span class="o">{</span>
<span class="n">t</span><span class="o">.</span><span class="na">printStackTrace</span><span class="o">();</span>
<span class="o">}</span>
<span class="n">i</span><span class="o">--;</span>
<span class="o">}</span>
<span class="n">list</span><span class="o">.</span><span class="na">addAll</span><span class="o">(</span><span class="n">list2</span><span class="o">);</span>
<span class="k">return</span> <span class="n">list</span><span class="o">.</span><span class="na">size</span><span class="o">();</span>
<span class="o">}</span>
<span class="kd">private</span> <span class="kd">static</span> <span class="kt">void</span> <span class="nf">hehe</span><span class="o">(</span><span class="kt">int</span> <span class="n">i</span><span class="o">)</span> <span class="o">{</span>
<span class="k">if</span> <span class="o">(</span><span class="n">i</span> <span class="o">==</span> <span class="mi">0</span><span class="o">)</span> <span class="o">{</span>
<span class="k">throw</span> <span class="k">new</span> <span class="n">RuntimeException</span><span class="o">(</span><span class="s">"ZERO"</span><span class="o">);</span>
<span class="o">}</span>
<span class="o">}</span>
</pre></div>
</div>
<p>监测 <code class="docutils literal notranslate"><span class="pre">add</span></code> 方法：</p>
<div class="highlight-shell notranslate"><div class="highlight"><pre><span></span>$ trace com.alibaba.sample.petstore.web.store.module.screen.ItemList add params.length<span class="o">==</span><span class="m">2</span>
Press Ctrl+C to abort.
Affect<span class="o">(</span>class-cnt:1 , method-cnt:1<span class="o">)</span> cost in <span class="m">144</span> ms.
<span class="sb">`</span>---Tracing...
<span class="sb">`</span>---<span class="o">[</span>2ms<span class="o">]</span>com.alibaba.sample.petstore.web.store.module.screen.ItemList:add<span class="o">()</span>
+---<span class="o">[</span><span class="m">0</span>,0,0ms,11<span class="o">]</span>com.alibaba.sample.petstore.web.store.module.screen.ItemList:hehe<span class="o">()</span> <span class="o">[</span>throws Exception<span class="o">]</span>
+---<span class="o">[</span>1ms<span class="o">]</span>java.lang.Throwable:printStackTrace<span class="o">()</span>
+---<span class="o">[</span>0ms<span class="o">]</span>java.util.List:addAll<span class="o">()</span>
<span class="sb">`</span>---<span class="o">[</span>0ms<span class="o">]</span>java.util.List:size<span class="o">()</span>
</pre></div>
</div>
<p>按照耗时过滤：</p>
<div class="highlight-shell notranslate"><div class="highlight"><pre><span></span>$ trace com.alibaba.sample.petstore.web.store.module.screen.ItemList execute <span class="c1">#cost>4</span>
Press Ctrl+C to abort.
Affect<span class="o">(</span>class-cnt:1 , method-cnt:1<span class="o">)</span> cost in <span class="m">159</span> ms.
trace com.alibaba.sample.petstore.web.store.module.screen.ItemList execute <span class="c1">#cost>4</span>
<span class="sb">`</span>---thread_name<span class="o">=</span>http-nio-8080-exec-5<span class="p">;</span><span class="nv">id</span><span class="o">=</span>2c<span class="p">;</span><span class="nv">is_daemon</span><span class="o">=</span>true<span class="p">;</span><span class="nv">priority</span><span class="o">=</span><span class="m">5</span><span class="p">;</span><span class="nv">TCCL</span><span class="o">=</span>com.taobao.pandora.boot.embedded.tomcat.TomcatEmbeddedWebappClassLoader
<span class="sb">`</span>---<span class="o">[</span><span class="m">8</span>.866586ms<span class="o">]</span> com.alibaba.sample.petstore.web.store.module.screen.ItemList:execute<span class="o">()</span>
+---<span class="o">[</span><span class="m">2</span>.847106ms<span class="o">]</span> com.alibaba.sample.petstore.biz.StoreManager:getAllProductItems<span class="o">()</span>
+---<span class="o">[</span><span class="m">0</span>.765544ms<span class="o">]</span> com.alibaba.sample.petstore.dal.dao.ProductDao:getProductById<span class="o">()</span>
+---<span class="o">[</span><span class="m">0</span>.021204ms<span class="o">]</span> com.alibaba.sample.petstore.dal.dataobject.Product:getCategoryId<span class="o">()</span>
+---<span class="o">[</span><span class="m">1</span>.341532ms<span class="o">]</span> com.alibaba.sample.petstore.dal.dao.CategoryDao:getCategoryById<span class="o">()</span>
<span class="sb">`</span>---<span class="o">[</span><span class="nv">min</span><span class="o">=</span><span class="m">0</span>.005428ms,max<span class="o">=</span><span class="m">0</span>.094064ms,total<span class="o">=</span><span class="m">0</span>.105228ms,count<span class="o">=</span><span class="m">3</span><span class="o">]</span> com.alibaba.citrus.turbine.Context:put<span class="o">()</span>
</pre></div>
</div>
<blockquote>
<div>只会展示耗时大于4ms的调用路径，有助于在排查问题的时候，只关注异常情况</div></blockquote>
<ul class="simple">
<li>是不是很眼熟，没错，在 JProfiler 等收费软件中你曾经见识类似的功能，这里你将可以通过命令就能打印出指定调用路径。 友情提醒下，<code class="docutils literal notranslate"><span class="pre">trace</span></code> 在执行的过程中本身是会有一定的性能开销，在统计的报告中并未像 JProfiler 一样预先减去其自身的统计开销。所以这统计出来有些许的不准，渲染路径上调用的类、方法越多，性能偏差越大。但还是能让你看清一些事情的。</li>
<li>[2ms] 的含义，<code class="docutils literal notranslate"><span class="pre">2</span></code> 的含义是：当前节点在当前步骤的耗时，单位为毫秒</li>
<li>[0,0,0ms,11]xxx:yyy() [throws Exception]，对该方法中相同的方法调用进行了合并，<code class="docutils literal notranslate"><span class="pre">0,0,0ms,11</span></code> 表示方法调用耗时，<code class="docutils literal notranslate"><span class="pre">min,max,total,count</span></code>；<code class="docutils literal notranslate"><span class="pre">throws</span> <span class="pre">Exception</span></code> 表明该方法调用中存在异常返回</li>
<li>这里存在一个统计不准确的问题，就是所有方法耗时加起来可能会小于该监测方法的总耗时，这个是由于 Arthas 本身的逻辑会有一定的耗时</li>
</ul>
</div>
</div>
</div>
</div>
<footer>
<div class="rst-footer-buttons" role="navigation" aria-label="footer navigation">
<a href="stack.html" class="btn btn-neutral float-right" title="stack" accesskey="n" rel="next">Next <span class="fa fa-arrow-circle-right"></span></a>
<a href="watch.html" class="btn btn-neutral" title="watch" accesskey="p" rel="prev"><span class="fa fa-arrow-circle-left"></span> Previous</a>
</div>
<hr/>
<div role="contentinfo">
<p>
© Copyright 2018, Alibaba Middleware Group, and contributors.
</p>
</div>
Built with <a href="http://sphinx-doc.org/">Sphinx</a> using a <a href="https://github.com/rtfd/sphinx_rtd_theme">theme</a> provided by <a href="https://readthedocs.org">Read the Docs</a>.
</footer>
</div>
</div>
</section>
</div>
<script type="text/javascript">
var DOCUMENTATION_OPTIONS = {
URL_ROOT:'./',
VERSION:'3.0.6-SNAPSHOT',
LANGUAGE:'zh_CN',
COLLAPSE_INDEX:false,
FILE_SUFFIX:'.html',
HAS_SOURCE: true,
SOURCELINK_SUFFIX: '.txt'
};
</script>
<script type="text/javascript" src="_static/jquery.js"></script>
<script type="text/javascript" src="_static/underscore.js"></script>
<script type="text/javascript" src="_static/doctools.js"></script>
<script type="text/javascript" src="_static/translations.js"></script>
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
<script type="text/javascript" src="_static/js/theme.js"></script>
<script type="text/javascript">
jQuery(function () {
SphinxRtdTheme.Navigation.enable(true);
});
</script>
<div class="github-fork-ribbon-wrapper right">
<div class="github-fork-ribbon">
<a href="https://github.com/alibaba/arthas">Fork me at GitHub</a>
</div>
</div>
<script type="text/javascript" src="_static/add_badges.js"></script>
<script>
var _hmt = _hmt || [];
(function() {
var hm = document.createElement("script");
hm.src = "https://hm.baidu.com/hm.js?d5c5e25b100f0eb51a4c35c8a86ea9b4";
var s = document.getElementsByTagName("script")[0];
s.parentNode.insertBefore(hm, s);
})();
</script>
</body>
</html>