Stateful junction concepts

Most Web-enabled applications maintain a "state" for a sequence of HTTP requests from a client. This state is used, for example, to:

• Track a user's progress through the fields in a data entry form generated by a CGI program
• Maintain a user's context when performing a series of database inquiries
• Maintain a list of items in an online shopping cart application where a user randomly browses and selects items to purchase

Back-end servers that run Web-enabled applications can be replicated in order to improve performance through load sharing. By default, Security Verify Access balances back-end server load by distributing requests across all available replicated servers. ISAM uses a "least-busy" algorithm. This algorithm directs each new request to the server with the fewest connections already in progress.

However, when WebSEAL processes a request over a stateful junction, WebSEAL must ensure that all subsequent requests from that client during that session are forwarded to the same server, and not distributed among the other replicated back-end servers according to the load balancing rules.

Parent topic: Stateful junctions