We use the Infinispan subsystem to create/configure caches for Keycloak. In standalone mode Keycloak uses locale-caches, while in clustered mode we use a combination of invalidation caches and distributed caches. In both clustered and non-clustered mode we use map-reduce tasks to delete elements from the cache.

This has worked just fine until the recent change in CR5 where locale-caches are now set to simple-caches (WFLY-5327). As the caches are now automatically set to simple-caches map-reduce is no longer available. There's also no way to prevent this.

IMO the changes from WFLY-5327 should be reverted and instead a new simple-cache element should be added, or a simple-cache=true attribute added to the locale-cache element.

As it stands this change prevents us from upgrading to CR5.