Hi this is my third part of the Tomcat Clustering Series . In this post we are going to discuss the how to setup session replication in tomcat clustering environment. Session replication makes High availability and full fail-over capability to our clustering environment. [Check the video below for better understanding] In my previous post we discussed about setup simple load balancer and how to make session affinity concepts. How to setup Session Replication in tomcat before going to session replication we need to understand 2 important concepts Multicast Session Manager in Tomcat Multicast Multicast is To transmit a single message to a select group of recipients. here multicast used by tomcat cluster to identify the instances those part of cluster. There is 2 types of cluster Static Tomcat Cluster Dynamic Tomcat Cluster In static cluster there is no need multicast, because each tomcat we statically defined/configured the other instances. Bu