I haven't spent a ton of time optimizing Tomcat, so caveat emptor. That said, you are using words like "assume" and "perhaps" so I think it'd be worthwhile for you to dig into the problem more and do some benchmarking before you optimize values.
- Get a benchmarking setup with
abwhere you can test your specific form against the server. The previously linked stress testing Aggregate should be of some help. - Turn on detailed monitoring on your instances and see if there's anything obvious there as far as incoming traffic being choked off.
- Use
htopto see if there is anything obviously wrong (maybe you have lots of CPU and RAM on the machine, but they aren't actually allocated to Tomcat?). - Read through both Tomcat, Aggregate, and MySQL logs to see if there is anything obvious.
- Confirm where the problem is (network, machine, Tomcat, MySQL) and what kind of problem it is and go from there.
For projects with massive traffic, what might be easier is to rethink the architecture. Have a load balancer that splits traffic between a few smaller Tomcat instances on EC2 and have those instances talk to a single large database on RDS.
As to Central, it's no longer in beta. We consider it stable and ready for production.