Recommend me a good book about tomcat/java performance tuning.
I'm a sysadmin and have to take care of several servers running tomcat and I would like to know more about the issue.
A decent tutorial might also be of interest.
"Pro Java EE 5, Performance Management and Optimization" is really excellent. It can be a little tedious to read in certain sections, but it's the best book I've found.
Also, you may have trouble finding a book that covers this topic with Tomcat, so you may need to find a good book on Java EE perf that covers a different app server. One that I also recommend is called "Jboss In Action".
Please be warned that this is a very big subject. Java performance spans everything from the JVM to the deployed application.