We currently have two different applications that use Oracle databases. Current configuration is two separate oracle homes dbhome_1, dbhome2 with separate LINUX mount points containing the Oracle homes and *.dbf files all on a single host server.
Previously the thought was to set up a second identical host server configured as a "data guard" for both of these databases. Now, management wants to implement a two node RAC cluster with each node running the both databases. With Standard Edition.
I have only done RAC for high availability and scalability for a single database. Is it possible to run two completely different Oracle databases on a two-node RAC cluster? I am inclined to suggest that they split it up into
two two-node RAC clusters on four smaller host servers. Any suggestions or comments would be appreciated?
Is it possible to run two completely different Oracle databases on a two-node RAC cluster?
Short answer is yes....it is possible. This will run with no issues as long you have the resources available for an additional database.
I am inclined to suggest that they split it up into two two-node RAC clusters on four smaller host servers.
This is another option. In the past I've had two databases on a RAC cluster which was implemented due to cost/licensing reasons ( I don't think this applies to SE, but you'll need to check).
However having having them on separate hosts mean that you will only potentially have downtime on one database if you decide to do something like upgrade one of the databases and as a result have to upgrade GI as well. This would mean downtime for all your databases which use the GI.
You may be limited by licensing issues, that you need to discuss with your management. Data Guard would need Enterprise Edition licenses per CPU multiplied by core factors, RAC needs only Standard Edition licences per CPU (no core factor). So your four node solution would need four Standard Edition licences, whereas the two node solution needs only two.
I've once encountered a RAC with 6 nodes, and 8 databases on it, each one running in all the nodes, so yea it is possible.
Just as a word of warning. You will have more than one Global SGA shipping blocks accross the same interconnect, so be sure to have a proper physical set up on your interconnect to support the added traffic or you may have major issues with interconnect performance.