Thanks.
There are multiple web servers(say 10) on the front.(Its Axis web application on
JBoss). So if one customer submits 50 requests, they will be load balanced. Keeping a track from web server level might be tough. After web server level , there is one Control server which will receive all these requests. This server will access DB to check currently how many requests are queued and hence how many more can be allowed. So DB read will be proportional to number of requests submitted.