Hi Michael, On Mon, Feb 9, 2009 at 6:03 PM, Michael Addyman <michael.addy...@googlemail.com> wrote: > Dear Geniuses, > > I have an application requiring ~30 InnoDB tables, which needs to scale up > to at least 500 application instances (500 instances * ~30 tables = 15,000 > tables). > > Discussions in the archives suggest I would be better off having independent > databases for each of the application instances (i.e. 500 databases). > > However, it seems this would be much more difficult/expensive to > manage/replicate/cluster than a single large database containing 15,000 > tables. > > Storing all the data from all the application instances in ~30 large tables > is not possible. > > Please could you give me your recommendations and experience? > > Many thanks, > > Michael >
This is not an easy question to answer without knowing a lot about your application's workload, which I suspect you will not be able to provide information on until you actually get some load. When you get a lot of InnoDB tables, one thing I can tell you is that the stock InnoDB will chew up a lot of memory for the data dictionary. We've recently patched InnoDB to alleviate this: http://www.percona.com/docs/wiki/patches:innodb_dict_size_limit If I were you I'd just go with your best educated guess, and when you get enough load to measure (not enough that you think you're going to be in trouble soon -- don't wait that long), call for expert help to find the most expensive parts of the app, and decide which are going to be hard to scale. It's usually difficult to predict in advance, but if you get some non-trivial load, you can then measure and have plenty of time to do something about what you find out. -- Baron Schwartz, Director of Consulting, Percona Inc. Our Blog: http://www.mysqlperformanceblog.com/ Our Services: http://www.percona.com/services.html -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=arch...@jab.org
