Hello team, we have Oracle RAC 11g on Extended Clusters of 2 nodes in 2 Datacenters (1 node in each DC). The distance between the 2 DC is 60Km. Oracle said "For distances greater than 50 km, there are not yet enough proof points to indicate the effect of deployments. More testing is needed to identify what types of workloads could be supported and what the effect of the chosen distance would have on performance." We are facing some issues with ASM losing contact with remote Luns, so the client ask us to come up with news ideas, because next year the distance between the 2 nodes will be over 80km.
Does any body knows any alternatives for a cluster with over 50kms distance?
The obvious alternative is Streams. The asynchronous communication is nearly real-time, and survives temporary network breaks no problem. Streams gets a lot of bad publicity (possibly because it is free with Enterprise Edition, so no-one makes any money when you implement it) but I have worked on number of implementations where it provides excellent fault tolerance, and runs unattended for months. A very robust solution if you configure it appropriately.