## Arthas
[](https://travis-ci.org/alibaba/arthas)
[](https://codecov.io/gh/alibaba/arthas)
[](http://isitmaintained.com/project/alibaba/arthas "Average time to resolve an issue")
[](http://isitmaintained.com/project/alibaba/arthas "Percentage of issues still open")
English version goes [here](README.md).
`Arthas` 是Alibaba开源的Java诊断工具，深受开发者喜爱。
当你遇到以下类似问题而束手无策时，`Arthas`可以帮助你解决：
0. 这个类从哪个 jar 包加载的？为什么会报各种类相关的 Exception？
0. 我改的代码为什么没有执行到？难道是我没 commit？分支搞错了？
0. 遇到问题无法在线上 debug，难道只能通过加日志再重新发布吗？
0. 线上遇到某个用户的数据处理有问题，但线上同样无法 debug，线下无法重现！
0. 是否有一个全局视角来查看系统的运行状况？
0. 有什么办法可以监控到JVM的实时运行状态？
`Arthas`支持JDK 6+，采用命令行交互模式，同时提供丰富的 `Tab` 自动补全功能，进一步方便进行问题的定位和诊断。
### 快速开始
#### 使用`arthas-boot`（推荐）
下载`arthas-boot.jar`，然后用`java -jar`的方式启动：
```bash
wget https://alibaba.github.io/arthas/arthas-boot.jar
java -jar arthas-boot.jar
```
打印帮助信息：
```bash
java -jar arthas-boot.jar -h
```
* 如果下载速度比较慢，可以使用aliyun的镜像：`java -jar arthas-boot.jar --repo-mirror aliyun --use-http`
#### 使用`as.sh`
Arthas 支持在 Linux/Unix/Mac 等平台上一键安装，请复制以下内容，并粘贴到命令行中，敲 `回车` 执行即可：
```bash
curl -L https://alibaba.github.io/arthas/install.sh | sh
```
上述命令会下载启动脚本文件 `as.sh` 到当前目录，你可以放在任何地方或将其加入到 `$PATH` 中。
直接在shell下面执行`./as.sh`，就会进入交互界面。
也可以执行`./as.sh -h`来获取更多参数信息。
### 文档
* [用户文档](https://alibaba.github.io/arthas/)
* [安装](https://alibaba.github.io/arthas/install-detail.html)
* [快速入门](https://alibaba.github.io/arthas/quick-start.html)
* [进阶使用](https://alibaba.github.io/arthas/advanced-use.html)
* [命令列表](https://alibaba.github.io/arthas/commands.html)
* [Docker](https://alibaba.github.io/arthas/docker.html)
* [用户案例](https://github.com/alibaba/arthas/issues?q=label%3Auser-case)
* [常见问题](https://github.com/alibaba/arthas/issues?utf8=%E2%9C%93&q=label%3Aquestion-answered+)
* [参与贡献](https://github.com/alibaba/arthas/blob/master/CONTRIBUTING.md)
* [Release Notes](https://alibaba.github.io/arthas/release-notes.html)
* [QQ群/钉钉群](https://alibaba.github.io/arthas/contact-us.html)
Gitee文档镜像： https://arthas.gitee.io/
### 案例展示
#### Dashboard
* https://alibaba.github.io/arthas/dashboard
#### Thread
一目了然的了解系统的状态，哪些线程比较占cpu？他们到底在做什么？
```
$ thread -n 3
"as-command-execute-daemon" Id=29 cpuUsage=75% RUNNABLE
at sun.management.ThreadImpl.dumpThreads0(Native Method)
at sun.management.ThreadImpl.getThreadInfo(ThreadImpl.java:440)
at com.taobao.arthas.core.command.monitor200.ThreadCommand$1.action(ThreadCommand.java:58)
at com.taobao.arthas.core.command.handler.AbstractCommandHandler.execute(AbstractCommandHandler.java:238)
at com.taobao.arthas.core.command.handler.DefaultCommandHandler.handleCommand(DefaultCommandHandler.java:67)
at com.taobao.arthas.core.server.ArthasServer$4.run(ArthasServer.java:276)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
Number of locked synchronizers = 1
- java.util.concurrent.ThreadPoolExecutor$Worker@6cd0b6f8
"as-session-expire-daemon" Id=25 cpuUsage=24% TIMED_WAITING
at java.lang.Thread.sleep(Native Method)
at com.taobao.arthas.core.server.DefaultSessionManager$2.run(DefaultSessionManager.java:85)
"Reference Handler" Id=2 cpuUsage=0% WAITING on java.lang.ref.Reference$Lock@69ba0f27
at java.lang.Object.wait(Native Method)
- waiting on java.lang.ref.Reference$Lock@69ba0f27
at java.lang.Object.wait(Object.java:503)
at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:133)
```
#### jad
对类进行反编译:
```java
$ jad javax.servlet.Servlet
ClassLoader:
+-java.net.URLClassLoader@6108b2d7
+-sun.misc.Launcher$AppClassLoader@18b4aac2
+-sun.misc.Launcher$ExtClassLoader@1ddf84b8
Location:
/Users/xxx/work/test/lib/servlet-api.jar
/*
* Decompiled with CFR 0_122.
*/
package javax.servlet;
import java.io.IOException;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
public interface Servlet {
public void init(ServletConfig var1) throws ServletException;
public ServletConfig getServletConfig();
public void service(ServletRequest var1, ServletResponse var2) throws ServletException, IOException;
public String getServletInfo();
public void destroy();
}
```
#### sc
查找JVM中已经加载的类
```
$ sc -d org.springframework.web.context.support.XmlWebApplicationContext
class-info org.springframework.web.context.support.XmlWebApplicationContext
code-source /Users/xxx/work/test/WEB-INF/lib/spring-web-3.2.11.RELEASE.jar
name org.springframework.web.context.support.XmlWebApplicationContext
isInterface false
isAnnotation false
isEnum false
isAnonymousClass false
isArray false
isLocalClass false
isMemberClass false
isPrimitive false
isSynthetic false
simple-name XmlWebApplicationContext
modifier public
annotation
interfaces
super-class +-org.springframework.web.context.support.AbstractRefreshableWebApplicationContext
+-org.springframework.context.support.AbstractRefreshableConfigApplicationContext
+-org.springframework.context.support.AbstractRefreshableApplicationContext
+-org.springframework.context.support.AbstractApplicationContext
+-org.springframework.core.io.DefaultResourceLoader
+-java.lang.Object
class-loader +-org.apache.catalina.loader.ParallelWebappClassLoader
+-java.net.URLClassLoader@6108b2d7
+-sun.misc.Launcher$AppClassLoader@18b4aac2
+-sun.misc.Launcher$ExtClassLoader@1ddf84b8
classLoaderHash 25131501
```
#### stack
查看方法 `test.arthas.TestStack#doGet` 的调用堆栈：
```
$ stack test.arthas.TestStack doGet
Press Ctrl+C to abort.
Affect(class-cnt:1 , method-cnt:1) cost in 286 ms.
ts=2018-09-18 10:11:45;thread_name=http-bio-8080-exec-10;id=d9;is_daemon=true;priority=5;TCCL=org.apache.catalina.loader.ParallelWebappClassLoader@25131501
@test.arthas.TestStack.doGet()
at javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:110)
...
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:451)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1121)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
```
#### Trace
观察方法执行的时候哪个子调用比较慢:
#### Watch
观察方法 `test.arthas.TestWatch#doGet` 执行的入参，仅当方法抛出异常时才输出。
```
$ watch test.arthas.TestWatch doGet {params[0], throwExp} -e
Press Ctrl+C to abort.
Affect(class-cnt:1 , method-cnt:1) cost in 65 ms.
ts=2018-09-18 10:26:28;result=@ArrayList[
@RequestFacade[org.apache.catalina.connector.RequestFacade@79f922b2],
@NullPointerException[java.lang.NullPointerException],
]
```
#### Monitor
监控某个特殊方法的调用统计数据，包括总调用次数，平均rt，成功率等信息，每隔5秒输出一次。
```
$ monitor -c 5 org.apache.dubbo.demo.provider.DemoServiceImpl sayHello
Press Ctrl+C to abort.
Affect(class-cnt:1 , method-cnt:1) cost in 109 ms.
timestamp class method total success fail avg-rt(ms) fail-rate
----------------------------------------------------------------------------------------------------------------------------
2018-09-20 09:45:32 org.apache.dubbo.demo.provider.DemoServiceImpl sayHello 5 5 0 0.67 0.00%
timestamp class method total success fail avg-rt(ms) fail-rate
----------------------------------------------------------------------------------------------------------------------------
2018-09-20 09:45:37 org.apache.dubbo.demo.provider.DemoServiceImpl sayHello 5 5 0 1.00 0.00%
timestamp class method total success fail avg-rt(ms) fail-rate
----------------------------------------------------------------------------------------------------------------------------
2018-09-20 09:45:42 org.apache.dubbo.demo.provider.DemoServiceImpl sayHello 5 5 0 0.43 0.00%
```
#### Time Tunnel(tt)
记录方法调用信息，支持事后查看方法调用的参数，返回值，抛出的异常等信息，仿佛穿越时空隧道回到调用现场一般。
```
$ tt -t org.apache.dubbo.demo.provider.DemoServiceImpl sayHello
Press Ctrl+C to abort.
Affect(class-cnt:1 , method-cnt:1) cost in 75 ms.
INDEX TIMESTAMP COST(ms) IS-RET IS-EXP OBJECT CLASS METHOD
-------------------------------------------------------------------------------------------------------------------------------------
1000 2018-09-20 09:54:10 1.971195 true false 0x55965cca DemoServiceImpl sayHello
1001 2018-09-20 09:54:11 0.215685 true false 0x55965cca DemoServiceImpl sayHello
1002 2018-09-20 09:54:12 0.236303 true false 0x55965cca DemoServiceImpl sayHello
1003 2018-09-20 09:54:13 0.159598 true false 0x55965cca DemoServiceImpl sayHello
1004 2018-09-20 09:54:14 0.201982 true false 0x55965cca DemoServiceImpl sayHello
1005 2018-09-20 09:54:15 0.214205 true false 0x55965cca DemoServiceImpl sayHello
1006 2018-09-20 09:54:16 0.241863 true false 0x55965cca DemoServiceImpl sayHello
1007 2018-09-20 09:54:17 0.305747 true false 0x55965cca DemoServiceImpl sayHello
1008 2018-09-20 09:54:18 0.18468 true false 0x55965cca DemoServiceImpl sayHello
```
#### Classloader
了解当前系统中有多少类加载器，以及每个加载器加载的类数量，帮助您判断是否有类加载器泄露。
```
$ classloader
name numberOfInstances loadedCountTotal
BootstrapClassLoader 1 3346
com.taobao.arthas.agent.ArthasClassloader 1 1262
java.net.URLClassLoader 2 1033
org.apache.catalina.loader.ParallelWebappClassLoader 1 628
sun.reflect.DelegatingClassLoader 166 166
sun.misc.Launcher$AppClassLoader 1 31
com.alibaba.fastjson.util.ASMClassLoader 6 15
sun.misc.Launcher$ExtClassLoader 1 7
org.jvnet.hk2.internal.DelegatingClassLoader 2 2
sun.reflect.misc.MethodUtil 1 1
```
#### Web Console
* https://alibaba.github.io/arthas/web-console
### Known Users
如果您在使用Arthas，请让我们知道，您的使用对我们非常重要：https://github.com/alibaba/arthas/issues/111 （按登记顺序排列）
### Credit
* [greys-anatomy](https://github.com/oldmanpushcart/greys-anatomy): Arthas代码基于Greys二次开发而来，非常感谢Greys之前所有的工作，以及Greys原作者对Arthas提出的意见和建议！
* [termd](https://github.com/termd/termd): Arthas的命令行实现基于termd开发，是一款优秀的命令行程序开发框架，感谢termd提供了优秀的框架。
* [crash](https://github.com/crashub/crash): Arthas的文本渲染功能基于crash中的文本渲染功能开发，可以从[这里](https://github.com/crashub/crash/tree/1.3.2/shell)看到源码，感谢crash在这方面所做的优秀工作。
* [cli](https://github.com/eclipse-vertx/vert.x/tree/master/src/main/java/io/vertx/core/cli): Arthas的命令行界面基于vert.x提供的cli库进行开发，感谢vert.x在这方面做的优秀工作。
### 仓库镜像
* [码云Arthas](https://gitee.com/arthas/arthas)