快速入门 === ## 1. 启动Demo ```bash wget https://alibaba.github.io/arthas/arthas-demo.jar java -jar arthas-demo.jar ``` `arthas-demo`是一个简单的程序，每隔一秒生成一个随机数，再执行质因式分解，并打印出分解结果。 `arthas-demo`源代码：[查看](https://github.com/alibaba/arthas/blob/master/demo/src/main/java/demo/MathGame.java) ## 2. 启动arthas 在命令行下面执行： ```bash $ wget https://alibaba.github.io/arthas/arthas-boot.jar $ java -jar arthas-boot.jar ``` * 执行该程序的用户需要和目标进程具有相同的权限。比如以`admin`用户来执行：`sudo su admin && java -jar arthas-boot.jar` 或 `sudo -u admin -EH java -jar arthas-boot.jar`。 * 如果attatch不上目标进程，可以查看`~/logs/arthas/` 目录下的日志。 * 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` * `java -jar arthas-boot.jar -h` 打印更多参数信息。 选择应用java进程： ``` $ $ java -jar arthas-boot.jar * [1]: 35542 [2]: 71560 arthas-demo.jar ``` Demo进程是第2个，则输入2，再输入回车/enter。Arthas会attach到目标进程上，并输出日志： ``` [INFO] Try to attach process 71560 [INFO] Attach process 71560 success. [INFO] arthas-client connect 127.0.0.1 3658 ,---. ,------. ,--------.,--. ,--. ,---. ,---. / O \ | .--. ''--. .--'| '--' | / O \ ' .-' | .-. || '--'.' | | | .--. || .-. |`. `-. | | | || |\ \ | | | | | || | | |.-' | `--' `--'`--' '--' `--' `--' `--'`--' `--'`-----' wiki: https://alibaba.github.io/arthas version: 3.0.5.20181127201536 pid: 71560 time: 2018-11-28 19:16:24 $ ``` ## 3. 查看dashboard 输入[dashboard](dashboard.md)，按enter/回车，会展示当前进程的信息，按`ctrl+c`可以中断执行。 ``` $ dashboard ID NAME GROUP PRIORI STATE %CPU TIME INTERRU DAEMON 17 pool-2-thread-1 system 5 WAITIN 67 0:0 false false 27 Timer-for-arthas-dashb system 10 RUNNAB 32 0:0 false true 11 AsyncAppender-Worker-a system 9 WAITIN 0 0:0 false true 9 Attach Listener system 9 RUNNAB 0 0:0 false true 3 Finalizer system 8 WAITIN 0 0:0 false true 2 Reference Handler system 10 WAITIN 0 0:0 false true 4 Signal Dispatcher system 9 RUNNAB 0 0:0 false true 26 as-command-execute-dae system 10 TIMED_ 0 0:0 false true 13 job-timeout system 9 TIMED_ 0 0:0 false true 1 main main 5 TIMED_ 0 0:0 false false 14 nioEventLoopGroup-2-1 system 10 RUNNAB 0 0:0 false false 18 nioEventLoopGroup-2-2 system 10 RUNNAB 0 0:0 false false 23 nioEventLoopGroup-2-3 system 10 RUNNAB 0 0:0 false false 15 nioEventLoopGroup-3-1 system 10 RUNNAB 0 0:0 false false Memory used total max usage GC heap 32M 155M 1820M 1.77% gc.ps_scavenge.count 4 ps_eden_space 14M 65M 672M 2.21% gc.ps_scavenge.time(m 166 ps_survivor_space 4M 5M 5M s) ps_old_gen 12M 85M 1365M 0.91% gc.ps_marksweep.count 0 nonheap 20M 23M -1 gc.ps_marksweep.time( 0 code_cache 3M 5M 240M 1.32% ms) Runtime os.name Mac OS X os.version 10.13.4 java.version 1.8.0_162 java.home /Library/Java/JavaVir tualMachines/jdk1.8.0 _162.jdk/Contents/Hom e/jre ``` ## 4. 通过thread命令来获取到进程的Main Class ``` $ thread -n -1 | grep 'main(' at demo.MathGame.main(MathGame.java:17) ``` ## 5. 通过jad来反编绎Main Class ```java $ jad demo.MathGame ClassLoader: +-sun.misc.Launcher$AppClassLoader@3d4eac69 +-sun.misc.Launcher$ExtClassLoader@66350f69 Location: /tmp/arthas-demo.jar /* * Decompiled with CFR 0_132. */ package demo; import java.io.PrintStream; import java.util.ArrayList; import java.util.Iterator; import java.util.List; import java.util.Random; import java.util.concurrent.TimeUnit; public class MathGame { private static Random random = new Random(); private int illegalArgumentCount = 0; public static void main(String[] args) throws InterruptedException { MathGame game = new MathGame(); do { game.run(); TimeUnit.SECONDS.sleep(1L); } while (true); } public void run() throws InterruptedException { try { int number = random.nextInt(); List primeFactors = this.primeFactors(number); MathGame.print(number, primeFactors); } catch (Exception e) { System.out.println(String.format("illegalArgumentCount:%3d, ", this.illegalArgumentCount) + e.getMessage()); } } public static void print(int number, List primeFactors) { StringBuffer sb = new StringBuffer("" + number + "="); Iterator iterator = primeFactors.iterator(); while (iterator.hasNext()) { int factor = iterator.next(); sb.append(factor).append('*'); } if (sb.charAt(sb.length() - 1) == '*') { sb.deleteCharAt(sb.length() - 1); } System.out.println(sb); } public List primeFactors(int number) { if (number < 2) { ++this.illegalArgumentCount; throw new IllegalArgumentException("number is: " + number + ", need >= 2"); } ArrayList result = new ArrayList(); int i = 2; while (i <= number) { if (number % i == 0) { result.add(i); number /= i; i = 2; continue; } ++i; } return result; } } Affect(row-cnt:1) cost in 970 ms. ``` ## 6. watch 通过[watch](watch.md)命令来查看`demo.MathGame#primeFactors`函数的返回值： ``` $ watch demo.MathGame primeFactors returnObj Press Ctrl+C to abort. Affect(class-cnt:1 , method-cnt:1) cost in 107 ms. ts=2018-11-28 19:22:30; [cost=1.715367ms] result=null ts=2018-11-28 19:22:31; [cost=0.185203ms] result=null ts=2018-11-28 19:22:32; [cost=19.012416ms] result=@ArrayList[ @Integer[5], @Integer[47], @Integer[2675531], ] ts=2018-11-28 19:22:33; [cost=0.311395ms] result=@ArrayList[ @Integer[2], @Integer[5], @Integer[317], @Integer[503], @Integer[887], ] ts=2018-11-28 19:22:34; [cost=10.136007ms] result=@ArrayList[ @Integer[2], @Integer[2], @Integer[3], @Integer[3], @Integer[31], @Integer[717593], ] ts=2018-11-28 19:22:35; [cost=29.969732ms] result=@ArrayList[ @Integer[5], @Integer[29], @Integer[7651739], ] ``` 更多的功能可以查看[进阶使用](advanced-use.md)。 ## 5. 退出arthas 如果只是退出当前的连接，可以用`quit`或者`exit`命令。Attach到目标进程上的arthas还会继续运行，端口会保持开放，下次连接时可以直接连接上。 如果想完全退出arthas，可以执行`shutdown`命令。