Hi, You might want to take a look at the new storage in keycloak[1].
Newer keycloak versions (19 and up) have a configurable storage for the auth sessions (see storage-area-auth-session and storage-area-user-session). I haven't checked them but the documentation is promising.
For older session (last time I checked keycloak 15) you might want to use offline sessions but they don't allow SSO after the auth session was evicted from infinispan.