Last week, we described the concept behind sticky sessions: you forward a request to the same upstream because there’s context data associated with the session on that node. However, if necessary, you should replicate the data to other upstreams because this one might go down. In this post, we are going to illustrate it with a demo. The overall design Design options are limitless. I’ll keep myself to a familiar stack, the JVM.

This is the 18th post in the Exercises in Programming Style focus series. The previous week, we shared data among threads to solve the now well-known word frequencies problem. The very next day, I joined Hazelcast as a Developer Advocate. Therefore, I thought it would be extremely interesting to use Hazelcast In-Memory-Data-Grid to improve on the previous solution.