Hi Vaadin developers 
I’m working on scaling my backend using multiple instances, and I’d like to store Spring Sessions in Hazelcast (using a Hazelcast Client) so session state can be shared across all backend nodes.
To do this, I followed the official guides:
However, after configuring everything, the app crashes with the following error:
Caused by: com.hazelcast.nio.serialization.HazelcastSerializationException:
Failed to serialize ‘com.vaadin.flow.spring.SpringVaadinSession’
My Question:
Is it possible to store Spring Sessions in Hazelcast Client without modifying Vaadin internals (like SpringVaadinSession)? If so, what’s the recommended way to make it work?
I understand that Vaadin manages its own session (VaadinSession) and stores it in the HttpSession, which Spring Session then attempts to serialize — but this seems to break with Hazelcast’s serialization.
Any guidance or best practices would be greatly appreciated — especially from anyone running Vaadin with Spring Boot + Hazelcast session clustering in production.
Thanks a lot!