I think this whole idea of don't go over a certain number of column families was a 2+ year old story. I remember hearing numbers like 5 or 6 (not 3) come up when talking at Hadoop conferences with engineers who were at companies that were heavy HBase users. I agree with Andrew's suggestion that we should remove that text and replace it with benchmarks. Obviously we need to provide disclaimers that these are benchmarks based on a specific schema design and so YMMV.
I have run a cluster with some tables having upwards of 5 CFs but the data was evenly spread across them. I don't think I saw any performance issues as such or maybe it got masked but 5 CFs was not a problem at all. Stack puts out an interesting stat i.e. ~15 CFs at FB. Do they run their own HBase version ? I feel they do and so they might have some enhancements which are not available to the community or that is no longer the case ? Thanks, Viral On Sun, Apr 7, 2013 at 3:52 PM, Andrew Purtell <[email protected]> wrote: > Is there a pointer to evidence/experiment backed analysis of this question? > I'm sure there is some basis for this text in the book but I recommend we > strike it. We could replace it with YCSB or LoadTestTool driven latency > graphs for different workloads maybe. Although that would also be a big > simplification of 'schema design' considerations, it would not be so > starkly lacking background. > > On Sunday, April 7, 2013, Ted Yu wrote: > > > From http://hbase.apache.org/book.html#number.of.cfs : > > > > HBase currently does not do well with anything above two or three column > > families so keep the number of column families in your schema low. > > > > Cheers > > > > On Sun, Apr 7, 2013 at 3:04 PM, Stack <[email protected] <javascript:;>> > > wrote: > > > > > On Sun, Apr 7, 2013 at 11:58 AM, Ted <[email protected]<javascript:;>> > > wrote: > > > > > > > With regard to number of column families, 3 is the recommended > maximum. > > > > > > > > > > How did you come up w/ the number '3'? Is it a 'hard' 3? Or does it > > > depend? If the latter, on what does it depend? > > > Thanks, > > > St.Ack > > > > > > > > -- > Best regards, > > - Andy > > Problems worthy of attack prove their worth by hitting back. - Piet Hein > (via Tom White) >
