Can we set up external infinispan in 26 version of Keycloak in single-site setup?
According to the documentation it is not clear.
From documentation:
External Infinispan in a single-site setup
If you are using an external Infinispan in a single-site setup, this was not supported in earlier versions of Keycloak and it is not supported in Keycloak 26. To protect users from using it accidentally via a manual configuration in Keycloak’s cache XML or via the CLI options, this is now guarded with a feature flag cache-embedded-remote-store. It is marked as experimental and is therefore not supported. Keycloak 26 will not start with such a configuration and show an error instead unless this experimental feature is enabled.
If you have been using an external Infinispan to keep users logged in between restarts and upgrades, use the persistent-user-sessions feature instead which is enabled by default. The external Infinispan is then no longer necessary.
The experimental feature cache-embedded-remote-store will be removed in a future minor release.