Administering Network Resources
Updated: August 22, 2005
Applies To: Windows Server 2003, Windows Server 2003 with SP1
IIS 6.0 provides a set of Quality of Service (QoS) features to help you maintain acceptable service levels of data transmission on your network. The goal of QoS is to ensure that particular sites or applications do not monopolize server resources, such as memory or CPU cycles, which can adversely affect performance. QoS helps administrators control how IIS components — such as sites, application pools, or the WWW service as a whole — use resources.
If the bandwidth on your server is not sufficient to support demand, you can increase overall server bandwidth. You can also increase the effective bandwidth of existing communication links. Some suggestions on how to do so follow; many involve setting parameters that can only be modified by editing the Windows registry or the IIS 6.0 metabase.
It is frequently possible to reduce your use of bandwidth by optimizing Web application scripts or content. This option is worth looking into as an interim solution, partly because it can also improve response time and the user experience; however, if your client base is growing, you might eventually have to increase the bandwidth of your network connection anyway.
You can sometimes effectively increase existing bandwidth by limiting connections, by increasing the length of the connection queues, or by enabling HTTP Keep-Alives.
QoS in IIS provides the following methods for managing and maintaining network performance:
Limiting Connections to Manage Resources: Set limits on the number of connections allowed to a Web or FTP server or to specific sites. Use this feature to ensure that all your services remain active during periods of peak use and to protect against malicious attack.
Enabling HTTP Keep-Alives to Keep Connections Open: To maintain an open connection when browsers send multiple requests to download a Web page, be sure that HTTP Keep-Alives are enabled.
Setting Connection Timeouts to Save Resources: To reduce the loss of processing resources consumed by idle connections, set connection timeouts on your Web server.
Using HTTP Compression for Faster Downloads: To provide faster transmission time between IIS and compression-enabled browsers, use HTTP compression.
Throttling Bandwidth to Manage Service Availability: Limit the bandwidth used by your Web server so that the server remains available for other services, such as e-mail or news, even during periods of peak use.
Using Other Features to Enhance Performance: In addition to the QoS features, use other IIS features, including Web gardens, idle timeout, CPU monitoring, and processor affinity, to help you manage system resources and enhance performance.