Sun Java System Web Server 6.1 SP6 Performance Tuning, Sizing, and Scaling Guide

Under-throttled Server

The server does not allow the number of active threads to exceed the thread limit value. If the number of simultaneous requests reaches that limit, the server stops servicing new connections until the old connections are freed up. This can lead to increased response time.

In Sun Java System Web Server, the server’s default RqThrottle value is 128. If you want your server to process more requests concurrently, you need to increase the RqThrottle value.

The symptom of an under-throttled server is a server with a long response time. Making a request from a browser establishes a connection fairly quickly to the server, but on under-throttled servers it may take a long time before the response comes back to the client.

The best way to tell if your server is being throttled is to see if the number of active sessions is close to, or equal to, the maximum number allowed via RqThrottle. To do this, seeMaximum Simultaneous RequestsMaximum Simultaneous Requests