We just switched from a single server to a cluster, with a load balancer out front to manage incoming connections. The load balancer makes the decision to go to app server 1 (app1) or app server 2 (app2) based on IP address - once a request comes in from one source IP, all future requests (for some period of time) go to the same server. The problem is that it appears that AOL will randomly assign an IP address to every request a user sends. So a user could end up going to both servers. With the exception of user login data, the code is reentrant, but I've had to store login information as cookies (max age = -1 so only for the current session) so that the user will automatically log in to the other server if/when they hit it. Although this approach seems to work, it also has some problems, and I was wondering if others had encountered this problem, and if there was a "standard" solution.
