ColdFusion 8 and jConsole

[ilssac]

I have been spending the last week tying to determine why our ColdFusion 8, Windows 2003 web server suddendly went from a historical average of 5% to 10% cpu usage to frequently spiking over 90%, which sets off all kinds of alarms with our operation staff, and maintaing a good 50% average.

The little I have been able to determine is that our main ColdFusion instance was using a fair amount of memory and frequently consuming 50% cpu usage on our two cpu box,/  We have two instances plus the cfusion administrator instance running in a ColdFusion multi-home setup.

This has lead me down the path of trying to dump and read threads for the first time in my career.  In learning how to do so, the jConsole tool has been recomeneded many times. I am wondering if anybody can give me some advice on using this tool?

• Does it work with the out-of-the-box JRun4 jvm that comes with ColdFusion 8?

• Is there anything else that needs to be done on the server other then adding the four Dcom.sun.management.jmxremote arguments to the java.args line in the jvm.config file? 

• I plan to install a Sun Java SDK on my workstation to run the jConsole tool, is there any concern about which version of the SDK I install, does it need to match the server in some manner?

TIA

Ian

[Adam Cameron.]

Ian, hopefully you've already sorted this out, but here's 2p worth:

• Does it work with the out-of-the-box JRun4 jvm that comes with ColdFusion 8?

Yes.

• Is there anything else that needs to be done on the server other then adding the four Dcom.sun.management.jmxremote arguments to the java.args line in the jvm.config file? 

Nope.

• I plan to install a Sun Java SDK on my workstation to run the jConsole tool, is there any concern about which version of the SDK I install, does it need to match the server in some manner?

Doesn't seem to be.  For the hell of it I just used a JDK1.5 version of jconsole to connect to my 1.6.0_04  CF8 instance.

--

Adam

[ilssac]

Well, yes and no, it has been sorted out.  Yes, I have sucessfully connected an instance of jConsole running on my workstation to the JRun servers running on Windows Server 2003.

But this has yet to lead to any answer on what is causing our stange CPU spinning problem.  Out of the blue, for an yet to be determined reason, the CPU will on our main instance will suddenly hit 50% usage and stay there until the JRun service is restarted.  The last time was over a the 4 day weekend from Feb 12th through Feb 15th.  The CPU hit 50% about midday Thursday the 11th and it did not stop until we restarted the service on Tuesday the 16th.

Here are several thread dumps I took during that period but I don't see anything out of the ordindary in these.

http://www.ilsweb.com/JRun4-stack-traces/

[Guest]

I have to ask this question - have you considered getting a demo license of Fusion Reactor?  We have used it on a number of occasions to identify misbehaving code and systems.  So much so it has paid for itself several times over.

[ilssac]

It's a possibility, but I would need a better understanding of what Fusion Reactor and|or SeeFusion offers that I am not getting with jConsole, the ColdFusion administrator monitor and other tools that I have already tried.

It's not so much that I can get to see what ColdFusion and the underlining JRun are doing.  It's more that everything I can see it doing should not cause this type of problem as best as I can tell.