> From: Chris Stewart [mailto:cstewart...@gmail.com] > Subject: Performance with Tomcat > > 1. Are there any tools or utilities we can use to get an understanding > of what Tomcat is doing while it's running (processes, memory per > process, and more)?
Your symptoms could have any number of causes: heap too small, heap too big, queueing points in the application, data base connection exhaustion, etc. For the first look, use JConsole. If possible, run it on the same platform as Tomcat; otherwise you'll have to set up for remote JMX access, which can be problematic behind firewalls and such. JConsole will give you a good overview of heap, CPU, and thread usage, and you can dig in deeper once you have a general idea of what's going wrong. If you're going through a lot of GCs, you'll probably need a bigger heap - but make sure you have enough RAM on the system to support the heap and the rest of the space needed by the Tomcat process. (Exceeding available RAM will get you into page thrashing.) If your threads are all blocking on the same object (e.g., DB connection pool), you'll need to increase concurrency somehow for that. The jstack tool is good for taking thread dumps on the fly. Both JConsole and jstack are in the Sun JDK. - Chuck THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers. --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
