目录
# 快速入门
可以通过下面的方式自己动手实践,也可以通过我们的在线教程在新窗口打开,跟随教程快速入门。
# 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:查看在新窗口打开
# 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-boot3.jar
java -jar arthas-boot3.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-boot3.jar
或sudo -u admin -EH java -jar arthas-boot3.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-boot3.jar --repo-mirror aliyun --use-http
java -jar arthas-boot3.jar -h
打印更多参数信息。
选择应用 java 进程:
$ $ java -jar arthas-boot3.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/3.x/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教程在新窗口打开。
# 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。