Were you using Keycloak also as the identity provider? IIRC, if you're using an external identity provider, and you want clustering, you can just deploy Keyclo

Were you using Keycloak also as the identity provider? IIRC, if you're using an external identity provider, and you want clustering, you can just deploy Keycloak containers and load balance between them. You can then load a shared cache if you want (or need). My memory is fuzzy right now, but although it isn't the leanest solution, I don't remember it as terrible. Ours wasn't a very custom solution anyway, we just hit an LDAP in the back and that was all.