mjhjmtu

My Application is installed on JBOSS EAp 6.1 .Few days back we found that the application slowness or end user not able to access the application.

We took ps -aux logs, and one of the output is below.

[Mon Jun 12 08:55:29.218 2017] 500 46257 90.7 10.2 22713508 6779044 ? Sl Apr26 61791:48 /usr/lib/jvm/java-1.7.0-openjdk-1.7.0.45.x86_64/jre/bin/java -D[Standalone] -server -XX:+UseCompressedOops -Xms2048m -Xmx4096m -XX:MaxPermSize=512m -Djava

Looks like this java process was hogging my CPU.but also its in Sl mode. This is my assumption.

Can this be the reason of application problem?

What could be the reason of high cpu usage?

What is the role of this process in JBOSS application server?

We didn't take thread dump and Gc logs (gc logs not enabled later we checked) and restarted the server. Now no logs.

The output you are showing doesn't show any application except the javavm running as a server.

High CPU load is quiet often seen in Java Applications when the used memory is nearly at the limit. The garbage collection runs all the time to free up memory again. This slows down the application performance and utilized nearly all cpu cycles.

Since you already killed the process, the chances to figure it out is gone.

For the future my suggestion is to configure a way to monitor the JVM:

• Adding GCLog is a simple approach.


• Adding JMX Remote Monitoring (please add authentication!) see:
  http://docs.oracle.com/javase/7/docs/technotes/guides/management/agent.html
  


• Allowing a third party agent to directly attach to the java virtual machine.

If you are again in such a situation, you can do following:

Getting a Java Stack-Trace of the Java Instance:

(Java running with PID 46257)
jstack -l 46257 >jstack-output.log

Then make a Heap-Dump to further analytics:
jmap -dump:live,format=b,file=jmap-heapdump.hprof 46257

Analysing the hprof-heapdumps can be done by various tools ( google: java heapdump analyzer ). This may help you to get a better cause for the high cpu load.