Jboss Scanner Thread high CPU usage waiting on condition

[davidwang]

I am using 3.2.3 on Linux (RedHat Advanced Server 2.1). After a few hours of running, the thread keep using a lot of CPU, constantly at 90%+. Then a few hours later, the VM Periodic Thread also shows 90% constantly. The system is light weighted. The stack traces shows that Scanner thread is executing Sleep(5000) while VM Periodic Thread is waiting on conditions. My question is why Sleeping and Waiting would consume 90%+ CPU on Linux. To make things worst, when this happens, it will never go away unless JBOSS is restarted. Some times, the JBOSS may even stop responding and restart JBOSS is the only options. This is repeatable after a few hours of running.

Is this a know bug for JBOSS? Any help would be appreciated!

David

--------------
The following is the stack trace of JVM:

"ScannerThread" daemon prio=1 tid=0x626f4938 nid=0x20ee waiting on condition [62
b91000..62b918c8]
at java.lang.Thread.sleep(Native Method)
at org.jboss.deployment.scanner.AbstractDeploymentScanner$ScannerThread.
loop(AbstractDeploymentScanner.java:218)
at org.jboss.deployment.scanner.AbstractDeploymentScanner$ScannerThread.
run(AbstractDeploymentScanner.java:191)


"VM Periodic Task Thread" prio=1 tid=0x080c0f78 nid=0x20a5 waiting on condition
"Suspend Checker Thread" prio=1 tid=0x080bc2a8 nid=0x20a0 runnable


----------

The following is the TOP view on Linux:

1:13am up 11 days, 17:41, 4 users, load average: 7.61, 6.76, 6.33
340 processes: 330 sleeping, 10 running, 0 zombie, 0 stopped
CPU0 states: 52.0% user, 47.4% system, 0.0% nice, 0.0% idle
CPU1 states: 31.3% user, 68.1% system, 0.0% nice, 0.0% idle
CPU2 states: 27.1% user, 72.3% system, 0.0% nice, 0.0% idle
CPU3 states: 88.2% user, 10.4% system, 0.0% nice, 0.3% idle
Mem: 2058320K av, 2052428K used, 5892K free, 336632K shrd, 10968K buff
Swap: 2097136K av, 1963092K used, 134044K free 203456K cached

PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME COMMAND
8357 pnadmin 25 0 201M 70M 72976 R 69.7 3.4 44:08 java
8430 pnadmin 25 0 201M 70M 72976 R 63.5 3.4 620:50 java
12 root 25 0 0 0 0 SW 45.1 0.0 1172m krefilld
696 oracle 17 0 105M 104M 103M S 15.0 5.1 1:01 oracle
8348 pnadmin 18 0 201M 70M 72976 S 13.6 3.4 13:09 java
5799 oracle 15 0 280M 279M 278M S 6.7 13.8 16:24 oracle
10 root 15 0 0 0 0 SW 5.9 0.0 40:53 kswapd

[juha]

Sounds like a bug in the Linux VM.

[clebertsuconic]

I'm not sure about that. Consider this just ideas please, as these are guesses only:

- Maybe it's something about the JVM version you are using.
- Is there any semaphores config in Linux you could tun?
- Did you try writting a simple java-main style program doing the same Thread.sleep()?

Clebert Suconic

[genman]

sleep() and wait()s shouldn't use any CPU. What does a JBoss server with nothing installed do?

[knutschik]

Hi all!
I have the same problem on Solaris 9 and restart the server is the only option. In the server there is no application deployed.
What happens...

[mbeyer73]

Any news on that matter?
How did you solve that problem?