Forum Discussion
OracleGuru_6934
Feb 25, 2009Nimbostratus
Hi Aaron,
You're right the failover of nodes in a RAC 10g and later cluster is seamless. The ability of the app to seamlessly failover from node to node depending on how it's connectivity is configured may be another matter, but my question is purely focused on cluster to cluster failover. Consider two RAC clusters local to each other, one the primary, the other a local standby, i.e. same data center, and a 3rd cluster in a remote data center. Oracle's Data Guard will handle the failover of the Oracle RAC Cluster to either the local standby or the remote standby. The preferred failover target is the local standby, backed up by the remote standby. My challenge here is how to seamlessly repoint the 100+ application servers from the primary cluster to the local standby and back again without having to do any type of a restart of the app servers, or bounce of the connection pools from the app servers. I've used the F5 BIG-IP and Cisco Catalyst for load balancing of app server connections to my cluster nodes when a thin java client was in place, but this is different in that their current application as it exists today, can't manage the persistence or caching of transactional data. As a result, in the event of any complete cluster failure, they are shutting down every app server and manually repointing them after the standby database cluster is up and running. We could use FAN and FCF and an application API to dynamically manage the failover, but their app won't support it. Hence, I'm looking outside the box at alternatives to enable a "rapid application failover" that can execute in minutes without dropping the connection pools allowing the app servers to "simply" failover to the standby database cluster as the primary database cluster fails over the same standby database cluster.
It's not relevant in a remote DR scenario as a complete duplicate set of app servers exist which will have to be brought up anyway in the event of a primary "site" failure.
HTH clarify what I'm trying to architect.
Again, thanks to anyone who can shed some insight on how to configure the F5's to support this.
Bill