Sun Java System Application Server 9.1 Performance Tuning Guide

Tuning HTTP Listener Settings

Change HTTP listener settings in the Admin Console under Configurations > config-name > HTTP Service > HTTP Listeners > listener-name.

Network Address

For machines with only one network interface card (NIC), set the network address to the IP address of the machine (for example, instead of default If you specify an IP address other than, the server will make one less system call per connection. Specify an IP address other than for best possible performance. If the server has multiple NIC cards then create multiple listeners for each NIC.

Acceptor Threads

The Acceptor Threads setting specifies how many threads you want in accept mode on a listen socket at any time. It is a good practice to set this to less than or equal to the number of CPUs in your system.

In the Application Server, acceptor threads on an HTTP Listener accept connections and put them onto a connection queue. Session threads then pick up connections from the queue and service the requests. The server posts more session threads if required at the end of the request.

The policy for adding new threads is based on the connection queue state: