Thanks..but write ALL will fail for any downed nodes. I am thinking of QUORAM.
From: Jason Tang [mailto:ares.t...@gmail.com] Sent: Tuesday, July 17, 2012 8:24 PM To: user@cassandra.apache.org Subject: Re: Replication factor - Consistency Questions Hi I am starting using Cassandra for not a long time, and also have problems in consistency. Here is some thinking. If you have Write:Any / Read:One, it will have consistency problem, and if you want to repair, check your schema, and check the parameter "Read repair chance: " http://wiki.apache.org/cassandra/StorageConfiguration And if you want to get consistency result, my suggestion is to have Write:ALL / Read:One, since for Cassandra, write is more faster then read. For performance impact, you need to test your traffic, and if your memory can not cache all your data, or your network is not fast enough, then yes, it will impact to write one more node. BRs 2012/7/18 Jay Parashar <jparas...@itscape.com> Hello all, There is a lot of material on Replication factor and Consistency level but I am a little confused by what is happening on my setup. (Cassandra 1.1.2). I would appreciate any answers. My Setup: A cluster of 2 nodes evenly balanced. My RF =2, Consistency Level; Write = ANY and Read = 1 I know that my consistency is Weak but since my RF = 2, I thought data would be just duplicated in both the nodes but sometimes, querying does not give me the correct (or gives partial) results. In other times, it gives me the right results Is the Read Repair going on after the first query? But as RF = 2, data is duplicated then why the repair? Note: My query is done a while after the Writes so data should have been in both the nodes. Or is this not the case (flushing not happening etc)? I am thinking of making the Write as 1 and Read as QUORAM so R + W > RF (1 + 2 > 2) to give strong consistency. Will that affect performance a lot (generally speaking)? Thanks in advance Regards Jay
