How to handle hazelcast in case of ClassNotFoundException when deploying application

Question

I'm curious how to handle an application deployment with a running hazelcast cluster. Scenario: I have some tomcat servers all running my application and they are all part of the hazelcast cluster. I now try to deploy a new version of my application on the servers step by step, so I won't have any downtime. The problem is now, that there where some changes on a class used in the hazelcast cache. When I now start deploying, the new application uses the new class for reading/writing and the old applications which are still up using the old version of the class. Now I have really a lot ClassNotFoundExceptions because of the class inconsistency. So is anyone out there knowing how to handle this properly or maybe a best practice to prevent this scenario at all? I'm not into the ops stuff this much but like you know, someones got to do it.

Answer 1

It looks like the portable serialization is what I was looking for.

http://docs.hazelcast.org/docs/3.9/manual/html-single/index.html#versioning-for-portable-serialization