Scalability, flexibility and agility are the cornerstones of successful cloud deployments. Customers across the globe have relied on Oracle Database Real Application Clusters (RAC) for their database cloud systems. Oracle 12c comes with significant enhancements, including scalability and high availability with such features as Flex Clusters, Flex ASM, Application Continuity and Transaction Guard.
We brought together a group of expert DBAs, geeks and IT/System administrators to share what they thought about Oracle RAC 12c release and how to get the most out of this new release. They joined hosts Leighton Nelson (@leight0nn), Oracle ACE, Oracle Certified Expert and Lead DBA at WorldWide Technologies, and Yury Velikanov (@yvelik), Oracle ACE Director and Oracle Infrastructure Architect at Google. We posed some key questions to the participants on the topic and here are some key takeaways from the conversation (you can see the full chat transcript at the end of this article).
Tip: Be sure to make use of database services
Many have hailed Oracle RAC 12c as the best release so far. Flex ASM and Oracle Scan improvements are much liked. Leighton Nelson believes that one of the common pitfalls when implementing RAC 12c is not using database services such as workload management, application affinity and more.
Tip: Avoid these common RAC performance issues
The participants agreed that the most common performance issues in an Oracle RAC environment are:
- Multipathing for ASM or ASMLib often gets neglected because it is often assumed that ASM will ensure storage HA, as Yury Velikanov noted
- Cluster waits can have negative impact
- Non-cached ordered sequences for primary keys
Tip: Avoid these common RAC configuration errors
Our experts agreed that some of the common configuration errors with Oracle RAC include:
- Undersized compute causing resource starvation and instance evictions
- Not using database services for instance affinity
- Running RAC on older versions
Tip: If running RAC on VMware, you need better visibility (try SolarWinds DPA)
Running RAC on VMWare creates greater complexity, and without tools to give you visibility on different layers, it may not be the best fit. Third-party tools such as SolarWinds Database Performance Analyzer can restore this much-needed visibility.
Tip: Applications running in a RAC environment must be RAC-aware
Finally, our experts agreed that applications running in a RAC environment need to be RAC-aware. RAC-aware applications ensure that:
- Failover is handled better
- Benefits of RAC are leveraged to the fullest extent
Conclusion
The success of its new features has catapulted RAC 12c to the status of a “superhero” among users in the Oracle community. With lots of new features added to an already impressive arsenal, we can easily liken it to the superhero Ironman for the worldwide users of Oracle.
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