Thanks for the quick response!. I will reconsider the schema. However, the problem troubles me somehow. How are schema changes supposed to be done? Should I serialize them, should I halt other cluster operations while I do the schema change? Is this a known problem with cassandra?
The other question, and I think the more important one for me now: how do I repair the cluster without loosing data once the schemas diverge? Right now the only way I have is erase all data and have the cluster start empty. Should this problem ever happen in production, it's important there's a way to recover the data. On Fri, Apr 15, 2011 at 1:57 PM, Dan Hendry <dan.hendry.j...@gmail.com>wrote: > Uh... don’t create a column family per user. Column families are meant to > be fairly static; conceptually equivalent to a table in a relational > database. Why do you need (or even want) a CF per user? Reconsider your data > model, a single column family with an inverted index for a ‘user’ column is > probably more what you are looking for. Operationally, the fewer CFs the > better. > > > > Dan > > > > *From:* Alejandro Perez [mailto:sp...@indextank.com] > *Sent:* April-15-11 16:39 > *To:* user@cassandra.apache.org > *Cc:* Support > *Subject:* Schemas diverging while dynamically creating CF. > > > > Hello, > > > > We're testing cassandra for integration with indextank. In this first try, > we're creating one column family for each user. In practice, on the first > run and for the first few documents (a few 100s), a new CF is created, and a > document is immediately added to it. A few (up to 50) requests of this type > are issued in parallel (for different column families). > > > > The end result, and quite repeatable, is having the cluster split with > different schema versions, and they never agree. > > > > Any thoughts? > > > > > > Thanks, > > > > Spike. > > > -- > > Alejandro Perez > IndexTank > > follow us @indextank <http://twitter.com/indextank> | read our > blog<http://blog.indextank.com/> | subscribe > our user mailing list <http://groups.google.com/group/indextank> > > > <http://blog.indextank.com/> > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 9.0.894 / Virus Database: 271.1.1/3574 - Release Date: 04/15/11 > 02:34:00 > -- Alejandro Perez IndexTank follow us @indextank <http://twitter.com/indextank> | read our blog<http://blog.indextank.com/> | subscribe our user mailing list <http://groups.google.com/group/indextank> <http://blog.indextank.com/>
