Implementation Guide › Performance Tuning › Web Tier Performance › Web Server Performance › Web Servers, Web Agents, and Web Server Processes

Web Servers, Web Agents, and Web Server Processes

Each Web Agent requires its own web server instance. IIS web servers, for example, operate using a single instance on the computer on which is it installed. The number of IIS Web Agents equals the number of IIS web servers.

For other Web Servers that support multiple instances per computer, you can install and configure one Web Agent for each instance. For example, you could have one computer that runs three separate web server instances. Each instance has its own Web Agent. Therefore, one computer operates three Web Agents.

The following illustration shows an example:

For Apache web servers, the following multi-processing modules (MRMs) affect how the Web Agent processes connect to the SiteMinder Policy Server:

• Pre-fork mode

  Creates child processes to handle additional requests.

• Worker mode

  Obtains additional threads from the connection pool to handle additional requests.