使用arthas定位java问题

1. 启动arthas，执行以下命令会提示所有java进程，选择进程id

wget https://arthas.aliyun.com/arthas-boot.jar
java -jar arthas-boot.jar

2. 使用dashboard或thread列出所有线程

dashboard
thread

3. 找出占用cpu或内存较高的线程，使用thread n列出线程堆栈

thread 1

输出：
"main" Id=1 TIMED_WAITING
at java.lang.Thread.sleep(Native Method)
at java.lang.Thread.sleep(Thread.java:340)
at java.util.concurrent.TimeUnit.sleep(TimeUnit.java:386)
at demo.MathGame.main(MathGame.java:17)

4. 通过sc查找出所有已加载的类

sc -d *MathGame

输出：
class-info demo.MathGame
code-source /data/arthas/arthas-demo.jar
name demo.MathGame

5. 反编译类

jad demo.MathGame

6. 监控类的输入输出

watch demo.MathGame primeFactors returnObj

7. 退出arthas

stop

https://arthas.aliyun.com/doc/arthas-tutorials.html?language=cn