[xwiki-users] Slow cache sync with JGroups / S3 in an EC2 cluster

We have deployed XWiki over a two-node EC2 cluster. We are using JGroups over S3 for cluster messaging as multicast does not work in EC2. I have noticed that if I edit a page on host A, and then refresh the same page from host B, it shows stale content — it takes up to a minute for the caches to sync. Is this something others have observed when running XWiki over multiple hosts? (I'm wondering if this is a JGroups/S3 issue)For people who are running XWiki in a cluster, how long does it typically take for changes made from one machine to show up in another?Are there any recommendations on how to speed up cache-sync time between XWiki hosts on a cluster? Also, in a cluster, is the default XWiki cache a distributed cache? Or is the same cache content replicated across all nodes in a cluster?