Oracle Data Guard Replication Support in Sun Cluster Express Geographic Edition
By timread on Jun 13, 2008
If you read the Solaris Cluster Express 6/08 available for download blog posting, you will have noticed that it mentioned that SCX Geographic Edition had been enhanced to support Oracle Data Guard replication. Now if you run Oracle 10g or 11g RAC in your data centers and need to integrate them into a disaster recovery framework that supports: Sun StorageTek Availability Suite (AVS), Hitachi TrueCopy and EMC SRDF then read on.
SCX Geographic Edition (SCXGE) is binary distribution of the open source version of Sun Cluster Geographic Edition (SCGE) that runs on Solaris Cluster Express (SCX) on top of Solaris Express Community Edition (SXCE) build 86. [We love our acronyms and abbreviations]. Trivia: did you know that SUN itself is an acronym that originally stood for Stanford University Networks?
Back to the plot... Services made highly available by SCX resource groups can grouped together in "protection groups". SCXGE then uses the robust start and stop methods of SCX to ensure that the protection group is migrated in a controlled fashion from a primary location to a standby site. This migration includes performing all the tasks needed to change the direction of data flow provided by the underlying replication technology. The advantage being that SCXGE hides the complexity of the individual replication methods behind a common command line interface. Thus switching a service from site A to site B is reduced to:
# geopg switchover -m newhost_cluster my-protection-pg
regardless of whether the replication was AVS, TC or SRDF based.
Support for Oracle Data Guard (ODG) extends SCXGE's capability beyond just software and storage based replication technologies. Internally, the ODG module uses the Oracle Data Guard broker interface which restricts its use to Oracle 10g and 11g RAC configurations only, i.e. no support for HA-Oracle.
So once you set up your Oracle RAC databases, configure ODG and create your Data Guard broker configuration, you can add that to your SCXGE configuration and have it monitored and controlled, just as you do for your other non-ODG protection groups. The module allows you to have multiple ODG protection groups, each with one or more ODG broker configuration in. Remember that each protection group can span any SCXGE partnership pair, so you can only have one primary and one standby database in each of these broker configurations.
If this has got you interested, feel free to download and install the SCX software bundle with the new ODG module and try it out. Just remember that this is the first build. I'm working on fixing all the bugs that my colleagues in QA discover, so keep an eye on this blog and the Open HA Cluster for news of any updates.
Although we don't offer support for this product, you can post questions in any of the usual forums (or is it fora ).