Currently there is a hardcoded limit on the number of regions that a region server can manage. Its 1500. Note that if the number of regions gets to around 1000 regions per region server, you end up with a performance hit. (YMMV)
So if you have 1 region per table, there's a real limit of 1500 tables * number of RS nodes. Note: You will probably die well before hitting this limit, again YMMV. On Jul 13, 2012, at 3:14 AM, N Keywal wrote: > Hi, > > There is no real limits as far as I know. As you will have one region > per table (at least :-), the number of region will be something to > monitor carefully if you need thousands of table. See > http://hbase.apache.org/book.html#arch.regions.size. > > Don't forget that you can add as many column as you want, and that an > empty cell cost nothing. For example, a class hierarchy is often > mapped to multiple tables in a RDBMS, while in HBase having a single > table for the same hierarchy makes much more sense. Moreover, there is > no transaction between tables, so sometimes a 'uml composition' will > go to a single table. And so on. > > N. > > On Fri, Jul 13, 2012 at 9:04 AM, Adrien Mogenet > <[email protected]> wrote: >> Hi there, >> >> I read some good practices about number of columns / column families, but >> nothing about the number of tables. >> What if I need to spread my data among hundred or thousand (big) tables ? >> What should I care about ? I guess I should keep a tight number of >> storeFiles per RegionServer ? >> >> -- >> Adrien Mogenet >> http://www.mogenet.me >
