Arthas quick start

Arthas （ Alsace ） What can I do for you ？

Arthas yes Alibaba Open source Java Diagnostic tools , Loved by developers . When you encounter the following similar problems and are at a loss , Arthas Can help you solve ：
1. Where does this class come from jar Package loaded ？ Why do you report all kinds of related Exception？
2. Why didn't I change the code to ？ I didn't commit？ The branch is wrong ？
3. I can't get online when I have a problem debug, Can't we just add logs and redistribute them ？
4. There is a problem with the data processing of a user online , But online also can't debug, It can't be reproduced offline ！
5. Is there a global perspective to see the health of the system ？
6. Is there any way to monitor JVM The real-time running state of ？
7. How to quickly locate the hot spot of application , Generate flame chart ？
Arthas Support JDK 6+, Support Linux/Mac/Winodws, Use command line interaction mode , At the same time, it provides rich Tab Automatic completion function , Further facilitate problem location and diagnosis .

windows Under the quick installation

download arthas-boot.jar, And then use java -jar Way to start

1、 New folder md arthas 2、 download jar package cd arthas curl -0 https://alibaba.github.io/arthas/arthas-boot.jar --output arthas The second way to download ： https://arthas.aliyun.com/doc/manual-install.html Download from the official website arthas The package , Extract locally and then install 3、 Check out the download directory dir You can see arthas-boot.jar My bag 4、 start-up java -jar arthas-boot.jar

You can open it on the browser page arthas, The default port is 3658 Address ：http://127.0.0.1:3658/

Familiar with common commands

1. dashboard Dashboard view java Virtual machine memory usage
2. thread Command to get demo Project progress Main class
3. adopt jad Decompile Main class
4. watch

1、dashboard

Input q, perhaps ctrl C Back out

2、thread Command to get demo Project progress Main class

Get demo project java On going Main class

thread 1 Will print threads ID 1 The stack , Usually main Thread of function

Clear all commands of the current window cls View the currently running thread thread View the stack information of a thread thread Thread number

3、 adopt jad Decompile Main class

jad Package name . Class name jad demo.MathGame

4、watch monitor

adopt watch Order to see demo.MathGame primeFactors The return value of the function

$ watch demo.MathGame primeFactors returnObj

5、 sign out arthas

If you just exit the current connection , It can be used quit perhaps exit command .Attach To the target process arthas It will continue to run , The port will remain open , The next time you connect, you can connect directly .

If you want to quit completely arthas, It can be executed stop command , It is equivalent to ending the whole session

Summary