In my organization we are using IIS7 in front of Tomcat 6.0.26. Now, before I get lots of responses that say "Don't use IIS" or "Use Apache" or "Use Tomcat Standalone," trust me, if I could follow that advice I would. IIS is specifically required for our organization and using any other configuration is not an option.
All conventional wisdom I could find online suggested that the opposite would happen, and my own experience as a programmer tells me that it should. We have checked all IIS performance options and everything is set to more-than adequate levels for the simulated load. Our JSP and Servlet response times did not change, and are much lower than 2950ms, so it seems unlikely (though not impossible) that some performance option in IIS could be causing this issue (seeing as how all the traffic is going through IIS one way or another).
Does anybody know what could be the cause here? We've spend days on this problem and we're not getting anywhere (and by we I mean myself a programmer, my manager and an IIS/server administrator). We just don't know what else to try.