*Updated 03/10/2022
This is a consistent question I receive often and although RAC isn't supported in any third-party cloud by Oracle, it's an important topic as more workloads lift and shift to Az...
Updated Mar 11, 2022
Version 2.0
Blog Post
DBAKevlar The "RAC is Not High Availability" statement seems to be very misleading. Multiple RAC users use it for HA specifically, including FlashGrid SkyCluster customers on Azure. Can it provide 100% uptime guarantee? Of course not, nothing can. But 99.99% or even 99.999% is achievable (using multi-AZ, which is the default in SkyCluster). So, the question is whether RAC is the best HA tool for Oracle database. My answer is yes, in most cases. All major release updates and most patches can be applied in rolling fashion. You don't have to do a manual failover in the middle of the night when a failure happens. And in case of RAC on SkyCluster, all "additional components" are packaged and pre-integrated together, so it just works. On the other hand, DataGuard is a great tool for disaster recovery, and our customers use it on top of RAC for doing async replication to a different region, in accordance with Oracle's Maximum Availability Architecture recommendations.