阿里重磅開源在線分析診斷工具Arthas(阿爾薩斯)

github地址:

Arthas

English version goes here.

Arthas 是Alibaba開源的Java診斷工具，深受開發者喜愛。

當你遇到以下類似問題而束手無策時，Arthas可以幫助你解決：

1. 這個類從哪個 jar 包加載的？為什么會報各種類相關的 Exception？
2. 我改的代碼為什么沒有執行到？難道是我沒 commit？分支搞錯了？
3. 遇到問題無法在線上 debug，難道只能通過加日志再重新發布嗎？
4. 線上遇到某個用戶的數據處理有問題，但線上同樣無法 debug，線下無法重現！
5. 是否有一個全局視角來查看系統的運行狀況？
6. 有什么辦法可以監控到JVM的實時運行狀態？

Arthas采用命令行交互模式，同時提供豐富的 Tab 自動補全功能，進一步方便進行問題的定位和診斷。

快速開始

Linux/Unix/Mac

安裝Arthas:

curl -L https://alibaba.github.io/arthas/install.sh | sh 

啟動Arthas:

./as.sh 

Windows

1. 點擊 這里 下載最新的Arthas zip包
2. 解壓縮zip包.
3. 進入bin目錄
4. 執行以下命令 as.bat $PID

文檔

社區正在進行英文版本的翻譯工作，如果您有興趣請在 這里留言。

• 用戶文檔
• 安裝
• 快速入門
• 進階使用
• Questions and answers
• 參與貢獻

案例展示

Dashboard

• https://alibaba.github.io/arthas/dashboard

Thread

一目了然的了解系統的狀態，哪些線程比較占cpu？他們到底在做什么？

1.  
   $ thread -n 3
2.  
   "as-command-execute-daemon" Id=29 cpuUsage=75% RUNNABLE
3.  
   at sun.management.ThreadImpl.dumpThreads 0(Native Method)
4.  
   at sun.management.ThreadImpl.getThreadInfo(ThreadImpl. java:440)
5.  
   at com.taobao.arthas.core.command.monitor20 0.ThreadCommand$1.action(ThreadCommand.java:58)
6.  
   at com.taobao.arthas.core.command.handler.AbstractCommandHandler.execute(AbstractCommandHandler. java:238)
7.  
   at com.taobao.arthas.core.command.handler.DefaultCommandHandler.handleCommand(DefaultCommandHandler. java:67)
8.  
   at com.taobao.arthas.core.server.ArthasServer$4.run(ArthasServer. java:276)
9.  
   at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor. java:1145)
10.  
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor. java:615)
11.  
    at java.lang.Thread.run(Thread. java:745)
12.  
     
13.  
    Number of locked synchronizers = 1
14.  
    - java.util.concurrent.ThreadPoolExecutor$Worker@6cd0b6f8
15.  
     
16.  
    "as-session-expire-daemon" Id=25 cpuUsage=24% TIMED_WAITING
17.  
    at java.lang.Thread.sleep(Native Method)
18.  
    at com.taobao.arthas.core.server.DefaultSessionManager$2.run(DefaultSessionManager. java:85)
19.  
     
20.  
    "Reference Handler" Id=2 cpuUsage=0% WAITING on java.lang.ref.Reference$Lock@69ba0f27
21.  
    at java.lang.Object.wait(Native Method)
22.  
    - waiting on java.lang.ref.Reference$Lock@69ba0f27
23.  
    at java.lang.Object.wait(Object. java:503)
24.  
    at java.lang.ref.Reference$ReferenceHandler.run(Reference. java:133)

jad

對類進行反編譯:

$ 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中已經加載的類

1.  
   $ sc -d org.springframework.web.context.support.XmlWebApplicationContext
2.  
   class-info org.springframework.web.context.support.XmlWebApplicationContext
3.  
   code-source /Users/xxx/work/test/WEB-INF/lib/spring-web- 3.2.11.RELEASE.jar
4.  
   name org.springframework.web.context.support.XmlWebApplicationContext
5.  
   isInterface false
6.  
   isAnnotation false
7.  
   isEnum false
8.  
   isAnonymousClass false
9.  
   isArray false
10.  
    isLocalClass false
11.  
    isMemberClass false
12.  
    isPrimitive false
13.  
    isSynthetic false
14.  
    simple-name XmlWebApplicationContext
15.  
    modifier public
16.  
    annotation
17.  
    interfaces
18.  
    super-class +-org.springframework.web.context.support.AbstractRefreshableWebApplicationContext
19.  
    +-org.springframework.context.support.AbstractRefreshableConfigApplicationContext
20.  
    +-org.springframework.context.support.AbstractRefreshableApplicationContext
21.  
    +-org.springframework.context.support.AbstractApplicationContext
22.  
    +-org.springframework.core.io.DefaultResourceLoader
23.  
    +-java.lang.Object
24.  
    class-loader +-org.apache.catalina.loader.ParallelWebappClassLoader
25.  
    +-java.net.URLClassLoader@6108b2d7
26.  
    +-sun.misc.Launcher$AppClassLoader@18b4aac2
27.  
    +-sun.misc.Launcher$ExtClassLoader@1ddf84b8
28.  
    classLoaderHash 25131501
29.  
     

stack

查看方法 test.arthas.TestStack#doGet 的調用堆棧：

1.  
   $ stack test.arthas.TestStack doGet
2.  
   Press Ctrl+C to abort.
3.  
   Affect( class-cnt:1 , method-cnt:1) cost in 286 ms.
4.  
   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
5.  
   @test.arthas.TestStack.doGet()
6.  
   at javax.servlet.http.HttpServlet.service(HttpServlet. java:624)
7.  
   at javax.servlet.http.HttpServlet.service(HttpServlet. java:731)
8.  
   at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain. java:303)
9.  
   at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain. java:208)
10.  
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter. java:52)
11.  
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain. java:241)
12.  
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain. java:208)
13.  
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain. java:241)
14.  
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain. java:208)
15.  
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve. java:220)
16.  
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve. java:110)
17.  
    ...
18.  
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve. java:169)
19.  
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve. java:103)
20.  
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve. java:116)
21.  
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter. java:451)
22.  
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor. java:1121)
23.  
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol. java:637)
24.  
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint. java:316)
25.  
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor. java:1142)
26.  
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor. java:617)
27.  
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread. java:61)
28.  
    at java.lang.Thread.run(Thread. java:745)

Trace

觀察方法執行的時候那個子調用比較慢:

Watch

觀察方法 test.arthas.TestWatch#doGet 執行的入參，僅當方法拋出異常時才輸出。

1.  
   $ watch test.arthas.TestWatch doGet {params[ 0], throwExp} -e
2.  
   Press Ctrl+C to abort.
3.  
   Affect( class-cnt:1 , method-cnt:1) cost in 65 ms.
4.  
   ts= 2018-09-18 10:26:28;result=@ArrayList[
5.  
   @RequestFacade[org.apache.catalina.connector.RequestFacade@79f922b2],
6.  
   @NullPointerException[java.lang.NullPointerException],
7.  
   ]

Classloader

了解當前系統中有多少類加載器，以及每個加載器加載的類數量，幫助您判斷是否有類加載器泄露。

1.  
   $ classloader
2.  
   name numberOfInstances loadedCountTotal
3.  
   BootstrapClassLoader 1 3346
4.  
   com.taobao.arthas.agent. ArthasClassloader 1 1262
5.  
   java.net. URLClassLoader 2 1033
6.  
   org.apache.catalina.loader. ParallelWebappClassLoader 1 628
7.  
   sun. reflect.DelegatingClassLoader 166 166
8.  
   sun.misc. Launcher$AppClassLoader 1 31
9.  
   com.alibaba.fastjson.util. ASMClassLoader 6 15
10.  
    sun.misc. Launcher$ExtClassLoader 1 7
11.  
    org.jvnet.hk2. internal.DelegatingClassLoader 2 2
12.  
    sun. reflect.misc.MethodUtil 1 1

Web Console

• https://alibaba.github.io/arthas/web-console