Hi, After doing much testing, I am able to recreate the "frozen server" situation on demand.
Strangely enough, it seems like the problem is caused by my use of org.apache.commons.lang.builder.ToStringBuilder in a (non-infinite) loop. When I remove the usage, the problem disappears. I'll have to do more investigation before I can reach a conclusion though On Fri, Feb 27, 2009 at 12:42 AM, Stella Lok <[email protected]> wrote: > Hi Kevan, > > The machine has one Xeon processor which is a dual core. I am running > WAS CE on IBM JSE 5. > > I do have the thread dump showing the blocked MQ threads, which I have > just forwarded to you, if you would like to take a look (if anyone > else is interested in taking a look, please let me know) > > Btw, the activemq used is not the one embedded in WASCE, but an external one. > > Thank you very much > > On Thu, Feb 26, 2009 at 11:13 PM, Kevan Miller <[email protected]> wrote: >> >> On Feb 26, 2009, at 5:58 AM, Stella Lok wrote: >> >>> Hi, >>> >>> I am using WAS CE 2.0.0.2 with ActiveMQ 5.2.0. While doing load >>> testing, I encountered situations when the web server (which is the >>> Tomcat embedded in WAS CE) permanently (until restart) stopped >>> responding to any HTTP requests (the catalina log stops logging new >>> requests), and none of the apps nor the admin console can be accessed >>> anymore. When that happens, the WAS CE java process' CPU utilization >>> would invariably be permanently stuck at around the 50% level, even if >>> I completely stop accessing the server. >>> >>> I did a thread dump whenever this occurred, and most of the time I do >>> not see any blocked threads, only runnable, parked and >>> waiting-on-condition threads. Once, I was able to see that there were >>> 4 blocked ActiveMQ threads, though I'm not sure if this is related. >>> >>> I would be most grateful if someone could help guide me to possible >>> causes of the problem. >> >> Hmm. Do you still have the thread dumps? Esp. the one showing the blocked >> AMQ threads? Is this a 2 CPU machine (e.g. a single dual core processor?) >> Sounds like you have a single thread spinning. A thread dump should help >> identify the culprit... Are you running on Sun or IBM JSE? >> >> --kevan >> >
