So, if my understanding is correct, in this case, the small replication factor key space is a online back system, or BCP environment. :)
Very good one. Actually, one of the things which make me a little bit uncomfortable is BCP: once something goes wrong, how to take it back? In the traditional RDBS world, there are lot of documented practices and procedures to follow to make it happen. As a relative new and improving technology, these stuff is very limited. (even google cannot help at the moment. :-)) Regards, Dop -----Original Message----- From: Benoit Perroud [mailto:ben...@noisette.ch] Sent: Saturday, April 10, 2010 5:48 PM To: user@cassandra.apache.org Subject: Re: How many KeySpace will you use in a single application? One point in using several keyspaces is that replication factor is per keyspace. If you have a part of your application which generate a lot of data whoss can be lost (some non critical logs?), then a dedicated keyspace with a smaller replication factor can be a good thing. Kind regards, Benoit. 2010/4/10 Dop Sun <su...@dopsun.com>: > Hi, a question troubles me now: how many KeySpaces one application is better > to use? > > > > The question is coming out since 0.6, Cassandra introduced a new API named > as “login”, which is done against a specific keySpace. Thanks to the > org.apache.cassandra.auth.AllowAllAuthenticator, the old version clients can > still work without authentication. > > > > Actually, while I’m working with the previous version, I just take the > KeySpace as another level of the whole structure, KeySpace – ColumnFamily – > Super Column (optional) – Column – Value. And consider the whole Cassandra > cluster as the root of all these, and one application controls everything > under this cluster. > > > > Now, looks like I need to re-think this and put the KeySpace as a kind of > root. It may be better to make one application only takes one KeySpace (a > silly question? Since all old time, one application usually uses only one > database, but forgive me, I may abuses the flexibility of Cassandra.)? Is > there any pros or cons to user multiple key spaces vs. single key spaces, > other than the authentication requirements? > > > > Can anyone give me some suggestions on this? > > > > Dop
