Golden rules of RAC performance diagnostics
Posted by Riyaj Shamsudeen on March 20, 2014
After collaborating with many performance engineers in a RAC database, I have come to realize that there are common pattern among the (mis)diagnosis. This blog about discussing those issues. I talked about this in Hotsos 2014 conference also.
Golden rules
Here are the golden rules of RAC performance diagnostics. These rules may not apply general RAC configuration issues though.
- Beware of top event tunnel vision
- Eliminate infrastructure as an issue
- Identify problem-inducing instance
- Review send-side metrics also
- Use histograms, not just averages
Looks like, this may be better read as a document. So, please use the pdf files of the presentation and a paper. Presentation slide #10 shows indepth coverage on gc buffer busy* wait events. I will try to blog about that slide later (hopefully).
Golden rules of RAC diagnostics paper
Golden rules of rac diagnostics ppt
Scripts mentioned in the presentation can be downloaded here.
Oracle database internals by Riyaj 
blueseine said
thank you for your sharing!
Oracle desde Guatemala » Blog Archive » Oracle ACE Newsletter Marzo 2014 said
[…] and discussed important differences between 11gand 12c database versions. In a separate post, he shares the guiding principles while diagnosing performance issues in a RAC […]
craig shallahamer said
Wait event time histograms rock. But v$event_histogram bins are not uniform so the picture we create in our head is misleading and can cause big problems, like this: https://www.youtube.com/watch?v=091-gN8kPjg