Redisson configuration for one redis shared by multiple tomcat instances

[marcelocastrillo]

I'm working with multiple Tomcat instances, each persisting its session data in Redis. Currently, each instance has its own Redis, and with a load balancer, we utilize sticky sessions to ensure that requests from the same user always go to the same server.

We are considering a change in the architecture to balance the load using round robin and employ a single Redis instance. This means that all Tomcat instances would share the same Redis.

My concern is, if a single Redis is used to store sessions for multiple Tomcat instances, is there a possibility of a collision in the session ID? In other words, could a session "x" be generated on one Tomcat and another session "x" on a different one, leading to a serious data leakage issue between users?

How can I configure redisson to make sure this isn't a problem? Does redisson checks if an id already exists when it creates a session?