I am currently using Tomcat5.5 in developing a web-application.Now i want to know what are all the possible steps i can take to upgrade server performance in order to boost my application's productivity........
I would first try to determine if Tomcat is actually a bottlneck.
Have you load tested your app while running it under a profiler like JProbe or OpitmizeIt to see where your bottlenecks actually are? If not, you could be wasting a lot of time fussing with the app server.
It will take a bit of work, but you really should simulate a load using realistic requests so - like Ben says - you can see if Tomcat really is a bottleneck. If your app does ANY database queries, Im betting on the DB connection being the bottleneck.