How to work with sessions across two servers

[Dinesh Kumar]

IF I have two different application servers that are to be load-balanced (serving one application eventually), how do I maintain sessions?

[Jimmy Clark]

Most commercial application servers support some sort of HttpSession failover functionality. The details of how this is done vary between severs and the load-balancing strategy/product used.

Basically, when a session object is created it is given an ID and saved a table in a database. When the balancer identifies a failure, if goes to the database and gets the session object and sends it to the second server. There are various design strategies for this behavior, i.e. memory-based replication.