@ -54,7 +54,7 @@ When the job is executing in the foreground, such as directly calling the comman
The job output can be redirect to the specified file by `>` or `>>`, and can be used together with `&` to implement the asynchronous job of the arthas command. such as:
```sh
```bash
$ trace Test t >> test.out &
```
@ -63,7 +63,7 @@ The trace command will be executed in the background and the output will be redi
When connecting to a remote arthas server, you may not be able to view the files of the remote machine. Arthas also supports automatic redirection to the local cache file. Examples are as follows:
`Arthas` is an Java Diagnostic tool open sourced by Alibaba.
`Arthas` is a Java Diagnostic tool open sourced by Alibaba.
Arthas can help developer trouble-shooting production issues for Java applications without modifying your code or restating your server.
Arthas help developers in trouble-shooting production issues for Java applications without modifying code or restarting servers.
### Background
In production system, sometimes the networks is unreachable from local development environment. If you encounter some issues in production system, it is impossible to use IDE to debug the application remotely. More importantly, debugging in production is unacceptable, because it will suspend all the threads, which leads to business unavailability.
Often times, the production system network is inaccessible from local development environment. If issues are encountered in production systems, it is impossible to use IDE to debug the application remotely. More importantly, debugging in production environment is unacceptable, as it will suspend all the threads, which leads to blocking of business services.
Some may think of reproducing the same issue on the test/staging environment, however, some tricky issue either can hardly be reproduced on a different environment, or even disappeared once restarted.
Developers could always try to reproduce the same issue on the test/staging environment. However, this is tricky as some issues cannot be be reproduced easily on a different environment, or even disappear once restarted.
Thinking of adding some logs to your code? You have to go through test, staging, and then on to production. Time is money! That is a lot inefficient! Besides, the issue may not be reproducible once restart your JVM, as described above.
And if you're thinking of adding some logs to your code to help trouble-shoot the issue, you will have to go through the following lifecycle; test, staging, and then to production. Time is money! This approach is inefficient! Besides, the issue may not be reproducible once the JVM is restarted, as described above.
Arthas is born to solve these issues. You can trouble-shoot your production issue on-the-fly. No JVM restart, no additional code changes. Arthas works as an observer, which will never suspend your existing threads.
Arthas was built to solve these issues. A developer can trouble-shoot your production issues on-the-fly. No JVM restart, no additional code changes. Arthas works as an observer, which will never suspend your existing threads.
### Key features
* Check whether a class is loaded? And whether is class loaded from? (Useful for trouble-shooting jar file conflicts)
* Check whether a class is loaded? Or where the class is loaded from? (Useful for trouble-shooting jar file conflicts)
* Decompile a class to ensure the code is running as expected.
* View classloader statistics, e.g. how may classloaders are there? how many class is loaded per classloader? What is the classloader hierarchy? Is there possible classloader leaks?
* View classloader statistics, e.g. the number of classloaders, the number of classes loaded per classloader, the classloader hierarchy, possible classloader leaks, etc.
* View the method invocation details, e.g. method parameter, return object, thrown exception, and etc.
* Check the stack trace of specified method invocation. This is useful when you would like to know who is calling your method?
* Check the stack trace of specified method invocation. This is useful when a developers wants to know the caller of the said method.
* Trace the method invocation to find slow sub-invocations.
* Monitor method invcation statistics, e.g. qps, rt, success rate and etc.
* Monitoring your system metrics, thread states and cpu usage, gc statistics, and etc.
* Support command line interactive mode, with auto completed feature enabled.
* Support telnet and websocket, which enables both local and remote diagnostics with command line and browsers.
* Monitor method invocation statistics, e.g. qps, rt, success rate and etc.
* Monitor system metrics, thread states and cpu usage, gc statistics, and etc.
* Supports command line interactive mode, with auto-complete feature enabled.
* Supports telnet and websocket, which enables both local and remote diagnostics with command line and browsers.
<spanid="use-to-run-the-command-in-the-background"></span><h2>1. Use & to run the command in the background<aclass="headerlink"href="#use-to-run-the-command-in-the-background"title="Permalink to this headline">¶</a></h2>
<p>For example, execute the trace command in the background:</p>
<divclass="highlight-sh notranslate"><divclass="highlight"><pre><span></span>trace Test t <spanclass="p">&</span>
<divclass="highlight-bash notranslate"><divclass="highlight"><pre><span></span>trace Test t <spanclass="p">&</span>
</pre></div>
</div>
</div>
<divclass="section"id="list-background-jobs">
<spanid="list-background-jobs"></span><h2>2. List background jobs<aclass="headerlink"href="#list-background-jobs"title="Permalink to this headline">¶</a></h2>
<p>If you want to list all background jobs, you can execute the <codeclass="docutils literal notranslate"><spanclass="pre">jobs</span></code> command and the results are as follows:</p>
<spanid="redirect-the-job-output"></span><h2>5. Redirect the job output<aclass="headerlink"href="#redirect-the-job-output"title="Permalink to this headline">¶</a></h2>
<p>The job output can be redirect to the specified file by <codeclass="docutils literal notranslate"><spanclass="pre">></span></code> or <codeclass="docutils literal notranslate"><spanclass="pre">>></span></code>, and can be used together with <codeclass="docutils literal notranslate"><spanclass="pre">&</span></code> to implement the asynchronous job of the arthas command. such as:</p>
<divclass="highlight-sh notranslate"><divclass="highlight"><pre><span></span>$ trace Test t >> test.out <spanclass="p">&</span>
<divclass="highlight-bash notranslate"><divclass="highlight"><pre><span></span>$ trace Test t >> test.out <spanclass="p">&</span>
</pre></div>
</div>
<p>The trace command will be executed in the background and the output will be redirect to <codeclass="docutils literal notranslate"><spanclass="pre">~/logs/arthas-cache/test.out</span></code>. You can continue to execute other commands in the console.</p>
<p>When connecting to a remote arthas server, you may not be able to view the files of the remote machine. Arthas also supports automatic redirection to the local cache file. Examples are as follows:</p>
<divclass="highlight-sh notranslate"><divclass="highlight"><pre><span></span>$ trace Test t >><spanclass="p">&</span>
<divclass="highlight-bash notranslate"><divclass="highlight"><pre><span></span>$ trace Test t >><spanclass="p">&</span>
<spanid="step-2-run-the-script"></span><h3>Step-2: Run the script<aclass="headerlink"href="#step-2-run-the-script"title="Permalink to this headline">¶</a></h3>
<p>Using <codeclass="docutils literal notranslate"><spanclass="pre">-b</span></code> to turn on script mode, and <codeclass="docutils literal notranslate"><spanclass="pre">-f</span></code> to run it and you can also <em>redirect</em> the output as:</p>
<spanid="step-3-check-the-outputs"></span><h3>Step-3: Check the outputs<aclass="headerlink"href="#step-3-check-the-outputs"title="Permalink to this headline">¶</a></h3>
<spanid="arthas-documentation"></span><h1>Arthas Documentation<aclass="headerlink"href="#arthas-documentation"title="Permalink to this headline">¶</a></h1>
<p><codeclass="docutils literal notranslate"><spanclass="pre">Arthas</span></code> is an Java Diagnostic tool open sourced by Alibaba.</p>
<p>Arthas can help developer trouble-shooting production issues for Java applications without modifying your code or restating your server.</p>
<p><codeclass="docutils literal notranslate"><spanclass="pre">Arthas</span></code> is a Java Diagnostic tool open sourced by Alibaba.</p>
<p>Arthas help developers in trouble-shooting production issues for Java applications without modifying code or restarting servers.</p>
<divclass="section"id="background">
<spanid="background"></span><h2>Background<aclass="headerlink"href="#background"title="Permalink to this headline">¶</a></h2>
<p>In production system, sometimes the networks is unreachable from local development environment. If you encounter some issues in production system, it is impossible to use IDE to debug the application remotely. More importantly, debugging in production is unacceptable, because it will suspend all the threads, which leads to business unavailability.</p>
<p>Some may think of reproducing the same issue on the test/staging environment, however, some tricky issue either can hardly be reproduced on a different environment, or even disappeared once restarted.</p>
<p>Thinking of adding some logs to your code? You have to go through test, staging, and then on to production. Time is money! That is a lot inefficient! Besides, the issue may not be reproducible once restart your JVM, as described above.</p>
<p>Arthas is born to solve these issues. You can trouble-shoot your production issue on-the-fly. No JVM restart, no additional code changes. Arthas works as an observer, which will never suspend your existing threads.</p>
<p>Often times, the production system network is inaccessible from local development environment. If issues are encountered in production systems, it is impossible to use IDE to debug the application remotely. More importantly, debugging in production environment is unacceptable, as it will suspend all the threads, which leads to blocking of business services.</p>
<p>Developers could always try to reproduce the same issue on the test/staging environment. However, this is tricky as some issues cannot be be reproduced easily on a different environment, or even disappear once restarted.</p>
<p>And if you’re thinking of adding some logs to your code to help trouble-shoot the issue, you will have to go through the following lifecycle; test, staging, and then to production. Time is money! This approach is inefficient! Besides, the issue may not be reproducible once the JVM is restarted, as described above.</p>
<p>Arthas was built to solve these issues. A developer can trouble-shoot your production issues on-the-fly. No JVM restart, no additional code changes. Arthas works as an observer, which will never suspend your existing threads.</p>
</div>
<divclass="section"id="key-features">
<spanid="key-features"></span><h2>Key features<aclass="headerlink"href="#key-features"title="Permalink to this headline">¶</a></h2>
<ulclass="simple">
<li>Check whether a class is loaded? And whether is class loaded from? (Useful for trouble-shooting jar file conflicts)</li>
<li>Check whether a class is loaded? Or where the class is loaded from? (Useful for trouble-shooting jar file conflicts)</li>
<li>Decompile a class to ensure the code is running as expected.</li>
<li>View classloader statistics, e.g. how may classloaders are there? how many class is loaded per classloader? What is the classloader hierarchy? Is there possible classloader leaks?</li>
<li>View classloader statistics, e.g. the number of classloaders, the number of classes loaded per classloader, the classloader hierarchy, possible classloader leaks, etc.</li>
<li>View the method invocation details, e.g. method parameter, return object, thrown exception, and etc.</li>
<li>Check the stack trace of specified method invocation. This is useful when you would like to know who is calling your method?</li>
<li>Check the stack trace of specified method invocation. This is useful when a developers wants to know the caller of the said method.</li>
<li>Trace the method invocation to find slow sub-invocations.</li>
<li>Monitor method invcation statistics, e.g. qps, rt, success rate and etc.</li>
<li>Monitoring your system metrics, thread states and cpu usage, gc statistics, and etc.</li>
<li>Support command line interactive mode, with auto completed feature enabled.</li>
<li>Support telnet and websocket, which enables both local and remote diagnostics with command line and browsers.</li>
<li>Monitor method invocation statistics, e.g. qps, rt, success rate and etc.</li>
<li>Monitor system metrics, thread states and cpu usage, gc statistics, and etc.</li>
<li>Supports command line interactive mode, with auto-complete feature enabled.</li>
<li>Supports telnet and websocket, which enables both local and remote diagnostics with command line and browsers.</li>
<spanid="log-command-outputs"></span><h1>Log command outputs<aclass="headerlink"href="#log-command-outputs"title="Permalink to this headline">¶</a></h1>
<p>Log command outputs for later analysis, turned off by default.</p>
<p>To turn it on, using <aclass="reference internal"href="options.html"><spanclass="doc">options</span></a> as:</p>
<spanid="thread-b-locate-the-blocking-threads"></span><h3>thread -b locate the blocking threads<aclass="headerlink"href="#thread-b-locate-the-blocking-threads"title="Permalink to this headline">¶</a></h3>
<p>Using <codeclass="docutils literal notranslate"><spanclass="pre">-b</span></code>, we can effectively locate the threads holding locks blocking other threads resulting in a frozen system.</p>
<spanid="thread-i-specify-the-collecting-interval"></span><h3>thread -i specify the collecting interval<aclass="headerlink"href="#thread-i-specify-the-collecting-interval"title="Permalink to this headline">¶</a></h3>
hengyunabc
6 years ago