+1 on changing the relationship between data persistence and scheduler rules. That's a directly addressable problem.
There was a thread on the ML a while ago dealing with the work load on the scheduler. The problem was that when the scheduler rules fire 55 times a second subsequent rules were interacting with the database at a multiple of the number of nodes in the cloud... such that 55 rule fires a second on a 10k node cloud was something on the order of 550k database interactions. While I'm interested in working with NoSQL databases, in memory fact-bases, and other interesting ways to deal with larger amounts of data that may not need a relational database... I've got a feeling we need to address this problem more directly rather than trying to optimize a central scheduler. Decentralizing the scheduler could solve the problem permanently, while optimizing a monolithic scheduler just prolongs how long you have before you are forced to address the core problem. That's just my 2 cents on the topic. # Shawn Hartsock ----- Original Message ----- > From: "Mike Spreitzer" <[email protected]> > To: "OpenStack Development Mailing List (not for usage questions)" > <[email protected]> > Sent: Monday, November 18, 2013 2:35:05 PM > Subject: [openstack-dev] [Nova] Does Nova really need an SQL database? > > There were some concerns expressed at the summit about scheduler > scalability in Nova, and a little recollection of Boris' proposal to keep > the needed state in memory. I also heard one guy say that he thinks Nova > does not really need a general SQL database, that a NOSQL database with a > bit of denormalization and/or client-maintained secondary indices could > suffice. Has that sort of thing been considered before? What is the > community's level of interest in exploring that? > > Thanks, > Mike > _______________________________________________ > OpenStack-dev mailing list > [email protected] > https://urldefense.proofpoint.com/v1/url?u=http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev&k=oIvRg1%2BdGAgOoM1BIlLLqw%3D%3D%0A&r=U9jd8i1QXRWQEdLI1XfrWPjXsJaoGrk8w31ffdfY7Wk%3D%0A&m=NwxAd6831JJcj%2FH7CoRa%2BVyaWBoKOth9FNmjCadmbeQ%3D%0A&s=58fde4a14f1b9bf8c7472739accdad2afcd72caf1914641cd02774d20e4a9cea > _______________________________________________ OpenStack-dev mailing list [email protected] http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
