Client sessions may be lost while accessing a Web Farm program in Windows NT Server 4.0 and Window 2000 Advanced Server

If a Web site depends on the ASP Session Object or some other state being stored on the Web server, clients of a Web farm program may experience problems. For example, sessions being "lost" between requests.

This issue can occur if a client request is serviced by a server that does not have the client's session-state information.

The Request Forwarding feature of Application Center 2000 addresses this behavior. For more information about Application Center 2000, please refer to the following Microsoft Web site: To resolve this issue, use any of the following methods:

• Design the Web site program to store its state on the client.
• Store the session state on a central server-side store, like a database.
• Design the client program to store session data in a cookie, embed it in the URL or manually (without Commerce Server) store the session data in a database.
• Use the "Affinity" or "Sticky Sessions" feature if you are using a Load Balancing service to cluster the Web servers (such as Microsoft Windows Load Balancing Service (WLBS) called Network Load Balancing (NLB) in Windows 2000) so that a client is always serviced by the same server. Please note that clients behind a farm of proxy servers cannot take advantage of the "Affinity" feature of WLBS/NLB when the external IP addresses used by the proxy servers span more than one 'class C' network ID. Note that AOL uses this type of proxy Web farms.

For additional information:

Maintaining Session State on Your Web Farm: