CF Line Debugging: CPU Load

[gkramer_1]

I've enabled Eclipse Debuggin for my CF application. I managed this with the Line Debugging option within CF Admin, which works perfectly. The Problem is, that seconds after I activated the Line Debugger on my server, the CPU load goes to 100%. This slows down my server and the application.

I already tried to give more RAM to my CF Server, that wasn't helping.

Is there any solution to this problem?

[Charlie Arehart]

There's no obvious explanation for that. I've never heard of the debugger causing a CPU problem. I'd suggest that whatever is happening, it's quite unusual.

Are you saying that it is in fact the jrun process (which underlies CF) that's reporting being at 100% CPU? If it is, have you viewed what the CF "runtime logs" say (not the cf "logs")? There may be some other problem that precedes the seeming "100% cpu" problem, and it may or may not be a memory problem. I discuss those logs and such problems in a recent blog entry:

http://www.carehart.org/blog/client/index.cfm/2010/11/3/when_memory_problems_arent_what_they_seem_part_1

That's a long URL, so if it splits over multiple lines as you view it here, please join them back together to paste into your browser.

Finally, is the server that's being debugged one that is running either CF Enterprise or the Developer edition? With those, you can run the CF Server Monitor, which allows you to see running requests. That may be insightful for you to know what requests, if any, are running as you observe this problem. For more on the server monitor, see a 4-part series of articles I did when CF8 came out, starting at:

http://www.carehart.org/articles/#2007_2

Hope that's helpful. Let us know what you find if you do not resolve the problem.

/charlie arehart

charlie@carehart.org

Providing CF and CFBuilder troubleshooting services

at http://www.carehart.org/consulting

[gkramer_1]

Thank you very much for your answer.

We checked the logs, as you recomented, but there were just timeout messages.

We activated another CPU for our server. By activating the CF Line Debugger option afterwards, we could recognise, that our CPU load remain stable but it stills slows down the server. Thus the whole server is slowly reacting, we receive the timeout errors.

Server Product:              ColdFusion

Version:                        9,0,0,251028 

Edition:                         Enterprise 

Operating System:         Windows Server 2008 

OS Version:                   6.0

Java Version:                 1.6.0_20

Datenbank:                    MSSQL 2008 (NICHT im Rückwärtskompatibilitätsmodus)

DB-Driver:                      JDBC 2.0

CPU:                             Dual-Core AMD Opteron Processor 8218 2.61 GHz

Memory (RAM):              4.00 GB

Thanks for your help.

[carl type3]

Hello,

Well sounds like two things you are sure of the CPU load and how it is related to line debugging. If the debugging is turned off does the CPU usage return to the former state? It is CF consuming the CPU and not sometime else - run TASKMANGR, process tab, view CPU time (might have to add that), JRun.EXE is the item taking most the time?

I see from the list you are on CF9, perhaps you do well to apply updater1 to bring it to CF9.0.1. Note tho there might be a problem for you with the updater1 as I see JVM is 1.6.0_20 and updater1 will perhaps want to switch to JVM _17. I raise it because likely you are using _20 for something and may need to enable _20 post update1 if indeed you decide to apply it or if it switches to _17.

You have Enterprise so can use CFMonitor. Does CFMonitor provide any clues?

There you go from one fellow CF user to another once again more questions than answers.

HTH, Carl.

[gkramer_1]

Hello and thanks again!

Yes, we are sure that it is the JRun.exe process.

We changed our JVM versions, like you recommended but it didn't help very much.

We discovered that just the first two (maybe three) requests are having a timeout error. Afterwards the debugging works fine, for about 7 to 10 requests, and then follows another timeout. Also it's never the same file which causes the error.

There are about 10 developer on our server but even if I set my allowed debug sessions to 1, there is a timeout.

Thank you very much!!

[Big Mad Kev]

When you say timeout, is that the CF Timeout?

When doing line debugging I find turning the request time out off in the CFAdmin, as you don't know how long you will hold the request for.

[carl type3]

Hello

>We changed our JVM versions, like you recommended but it didn't help very much.

Please note I suggested applying CF9 updater1 and mentioned that I was not sure what would happen JVM wise since updater1 normally uses JVM version 1.6.0_17 and you have applied 1.6.0_20. As reference to applying updater1:

http://www.adobe.com/cfusion/tdrc/index.cfm?product=coldfusion

says in part:

Adobe recommends that all ColdFusion 9 users apply this complimentary 9.0.1 update.

Having said all that I am curious did updater1 in-fact switch to JVM 1.6.0_17 or leave the one currently in use 1.6.0_20?

Anyway none of that helps you. So to be clear you have a JRun.EXE that is CPU bound when debug is on and time out messages. Some details on the time out message would perhaps assist. With JRun.EXE being busy I am interested to know if it is logging anything that might relate in ColdFusion9\runtime\logs\coldfusion-out.log ?

HTH, Carl.