We're pulling our hair out with a Tomcat issue. We have an in-house application running on Tomcat 5.5 with Sun JDK 1.6. The machine is an x86 dual-CPU, quad core (8 cores total) with 16GB of RAM. We're running OpenSuSE 10.2, 32-bit. Java memory size set to 2GB, multi-threaded GC enabled.
What occurs is when a user clicks a certain kind of analysis on the website, data is retrieved from a database and then a lot of formatting is done before returning it to the user. This typically causes 100% CPU usage for this thread for a few minutes (bioinformatics application, that part isn't going to change). Unfortunately what then occurs is all other threads suddenly become unusably slow. The entire web application grinds to a halt until this thread that's running hot completes. Looking at top, it appears that these threads aren't spreading among all the cores. I see one core go to 100% usage, and the others stay at 100% idle. So we're running multi-thread, but because everything is staying on the same core, we're still getting thread contention that's bringing the entire application to its knees. The only time I began to see the other cores actually start being used is when I enabled multi-threaded GC. But that doesn't give much improvement since the threads responding the web requests are still all on the same core. I'm not sure how to convince the Tomcat/Java container to spread its threads among the cores. Thanks. -- Matthew Laird Lead Software Developer, Bioinformatics Brinkman Laboratory, MBB Dept. Simon Fraser University --------------------------------------------------------------------- To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
