Quick Start¶
1. Start A Demo¶
Save the following code to a Demo.java and run the commands in shell as
javac Demo.java && java Demo
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
public class Demo {
static class Counter {
private static AtomicInteger count = new AtomicInteger(0);
public static void increment() {
count.incrementAndGet();
}
public static int value() {
return count.get();
}
}
public static void main(String[] args) throws InterruptedException {
while (true) {
Counter.increment();
System.out.println("counter: " + Counter.value());
TimeUnit.SECONDS.sleep(1);
}
}
}
2. Start Arthas¶
Linux/Unix/Mac¶
./as.sh
the user to run the command should have the same privilege as the owner of the target process, as a simple example you can try the following command if the target process is managed by user
admin:sudo su admin && ./as.sh # Or sudo -u admin -EH ./as.sh
For more details of the booting script, please refer to Start Arthas.
If you cannot attach the target process, please check the logs under
~/logs/arthasfor troubleshooting.Selecting the target process as:
$ ./as.sh Arthas script version: 3.0.2 Found existing java process, please choose one and hit RETURN. * [1]: 95428 [2]: 22647 org.jetbrains.jps.cmdline.Launcher [3]: 21736 [4]: 13560 Demo
We select
4to check our Demo process and we then haveConnecting to arthas server... current timestamp is 1536656867 Trying 127.0.0.1... Connected to 127.0.0.1. Escape character is '^]'. ,---. ,------. ,--------.,--. ,--. ,---. ,---. / O \ | .--. ''--. .--'| '--' | / O \ ' .-' | .-. || '--'.' | | | .--. || .-. |`. `-. | | | || |\ \ | | | | | || | | |.-' | `--' `--'`--' '--' `--' `--' `--'`--' `--'`-----' wiki: https://alibaba.github.io/arthas version: 3.0.1-RC-SNAPSHOT pid: 13560 timestamp: 1536656867894 $
Windows¶
Open the DOS console, under the unzipped arthas folder execture as.bat <pid>
3. Check the Dashboard¶
Type in dashboard and hit the ENTER, you will see it as (Ctrl+C to stop)
$ 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. watch¶
Input watch to check the returned value of Counter.value():
$ watch Demo$Counter value returnObj
Press Ctrl+C to abort.
Affect(class-cnt:1 , method-cnt:1) cost in 29 ms.
ts=2018-09-10 17:53:11;result=@Integer[621]
ts=2018-09-10 17:53:12;result=@Integer[622]
ts=2018-09-10 17:53:13;result=@Integer[623]
ts=2018-09-10 17:53:14;result=@Integer[624]
ts=2018-09-10 17:53:15;result=@Integer[625]
5. Exit Arthas¶
quitorexitwill just disconnect the current console connection while Arthas still running in the target processshutdownwill terminate the Arthas completely