Managing the session state is one of the important challenges in distributing and scaling web applications. HTTP is a stateless protocol. The state of the user interactions with web applications is typically managed in HttpSession.
It is important to have as little data as possible in a session. Focus on identifying and removing data that is not needed in the session.
Consider a distributed application with three instances, as shown here. Each of these instances has its own local session copy:
Imagine a user is being currently served from App Instance 1. Imagine if App Instance 1 goes down and the load balancer sends the user ...
