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使用arthas排查 test 问题

1. 启动math-game

 
curl -O https://arthas.aliyun.com/math-game.jar
 
java -jar math-game.jar

math-game是一个简单的程序,每隔一秒生成一个随机数,再执行质因数分解,并打印出分解结果。

math-game源代码:查看

2. 启动arthas

在命令行下面执行(使用和目标进程一致的用户启动,否则可能attach失败):

 
curl -O https://arthas.aliyun.com/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attach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 math-game.jar

math-game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://arthas.aliyun.com/doc
 
version: 3.0.5.20181127201536
 
pid: 71560
 
time: 2018-11-28 19:16:24
   
 
$

3. 查看dashboard

输入dashboard,按回车/enter,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math-game进程的Main Class

thread 1会打印线程ID 1的栈,通常是main函数的线程。

 
$ thread 1 | grep 'main('
 
at demo.MathGame.main(MathGame.java:17)

5. 通过jad来反编译Main Class

 
$ jad demo.MathGame
   
 
ClassLoader:
 
+-sun.misc.Launcher$AppClassLoader@3d4eac69
 
+-sun.misc.Launcher$ExtClassLoader@66350f69
   
 
Location:
 
/tmp/math-game.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<Integer> 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<Integer> primeFactors) {
 
StringBuffer sb = new StringBuffer("" + number + "=");
 
Iterator<Integer> 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<Integer> primeFactors(int number) {
 
if (number < 2) {
 
++this.illegalArgumentCount;
 
throw new IllegalArgumentException("number is: " + number + ", need >= 2");
 
}
 
ArrayList<Integer> result = new ArrayList<Integer>();
 
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

7. 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stop命令。

 

https://arthas.aliyun.com/doc/quick-start.html

因为相信,所以看见.
posted @ 2021-07-30 17:06  zeenzhou  阅读(26)  评论(0编辑  收藏  举报