[xwiki-users] Clustering of Xwiki

Hey everybody, I found some information on clustering for Xwiki where I have to set the observation.remote.enabled to true. Per my understanding the cache would be synchronized between every instance (via Jgroups). Now we want to use the following architecture: We have 2 datacenters. In each datacenter are 2 servers with a Xwiki instance running (so 4 instances in 2 datacenters). As database we want to use Oracle RAC. Is it possible to run these 4 instances on the Oracle RAC? Is it possible to invalidate the cache of another instance if one instance has some write action or something (so it generates a new cache on its own)? We would have 1 loadbalancer to manage the load between the two datacenters and 1 loadbalancer in every datacenter to manage the load between the 2 instances. Every instance should show the same content... Kind regards, Patrick