Listen Socket Information

The following listen socket information includes the IP address, port number, number of acceptor threads, and the default virtual server for the listen socket. For tuning purposes, the most important field in the listen socket information is the number of acceptor threads.

You can have many listen sockets enabled for virtual servers, but at least one will be enabled for your default server instance (usually http://0.0.0.0:80).

ListenSocket ls1:
------------------------
Address                   http://0.0.0.0:8080
Acceptor Threads          1
Default Virtual Server    https-iws-files2.red.iplanet.com

Tuning

You can create listen sockets through the Server Manager, and edit much of a listen socket’s information. For more information about adding and editing listen sockets, see the Sun Java System Web Server 6.1 SP12 Administrator’s Guide.

If you have created multiple listen sockets, perfdump displays all of them.

Set the TCP/IP listen queue size for all listen sockets by:

• Editing the ListenQ parameter in magnus.conf

• Setting or changing the ListenQ value in the Magnus Editor of the Server Manager

• Entering the value in the Listen Queue Size field of the Performance Tuning page of the Server Manager

Address

The Address field contains the base address that this listen socket is listening on. It contains the IP address and the port number.

If your listen socket listens on all IP addresses for the machine, the IP part of the address is 0.0.0.0.

Tuning

This setting is tunable when you edit a listen socket. If you specify an IP address other than 0.0.0.0, the server will make one less system call per connection. Specify an IP address other than 0.0.0.0 for best possible performance.

For more information about adding and editing listen sockets, see the Sun Java System Web Server 6.1 SP12 Administrator’s Guide.

Acceptor Threads

Acceptor threads are threads that wait for connections. The threads accept connections and put them in a queue where they are then picked up by worker threads. Ideally, you want to have enough acceptor threads so that there is always one available when a user needs one, but few enough so that they do not provide too much of a burden on the system. A good rule is to have one acceptor thread per CPU on your system. You can increase this value to about double the number of CPUs if you find indications of TCP/IP listen queue overruns.

Tuning

You can tune this number through the user interface when you edit a listen socket.

For more information about adding and editing listen sockets, see the Sun Java System Web Server 6.1 SP12 Administrator’s Guide.

Default Virtual Server

Software virtual servers work using the HTTP/1.1 Host header. If the end user’s browser does not send the Host header, or if the server cannot find the virtual server specified by the Host header, Sun Java System Web Server handles the request using a default virtual server. Also, for hardware virtual servers, if Sun Java System Web Server cannot find the virtual server corresponding to the IP address, it displays the default virtual server. You can configure the default virtual server to send an error message or serve pages from a special document root.

Tuning

You can specify a default virtual server for an individual listen socket and for the server instance. If a given listen socket does not have a default virtual server, the server instance’s default virtual server is used.

You can specify a default virtual server for a listen socket by:

• Setting or changing the default virtual server information using the Edit Listen Sockets page on the Preferences tab of the Server Manger.

• Editing the defaultvs attribute of the CONNECTIONGROUP element in the server.xml file. For more information about server.xml, see the Sun Java System Web Server 6.1 SP12 Administrator’s Configuration File Reference.