I'm using cassandra 0.6.4; there's a configuration option DoConsistencyChecksBoolean in storage-conf.xml. Is't that for read-repair ?
I will do a test for WRITE QUORUM, READ.ONE if it can meet our requirements. 2010/8/18 Edward Capriolo <edlinuxg...@gmail.com> > On Tue, Aug 17, 2010 at 10:55 PM, Chen Xinli <chen.d...@gmail.com> wrote: > > Hi, > > > > We are going to use cassandra for searching purpose like inbox search. > > The reading qps is very high, we'd like to use ConsitencyLevel.One for > > reading and disable read-repair at the same time. > > > > For reading consistency in this condition, the writing should use > > ConsistencyLevel.ALL. But the writing will fail if one node fails. > > We want such a ConsistencyLevel for writing/reading that : > > 1. writing will success if there is node alive for this key > > 2. reading will not forward to a node that's just recovered and doing > hinted > > handoff > > > > So that, if some node fails, others nodes for replica will receive the > data > > and surve reading successfully; > > when the failure node recovers, it will receive hinted handoff from > other > > nodes and it'll not surve reading until hinted handoff is done. > > > > Does cassandra support the cases already? or should I modify the code to > > meet our requirements? > > > > Thanks for any advices! > > > > -- > > Best Regards, > > Chen Xinli > > > > >>The reading qps is very high, we'd like to use ConsitencyLevel.One for > reading and disable read-repair at the same time. > You can not disable read repair, all reads no matter the > ConsistencyLevel always repair. The CL only controls how many nodes to > read from before returning data to the client. > > These two statements contradict. > > For reading consistency in this condition, the writing should use > ConsistencyLevel.ALL. But the writing will fail if one node fails. > > 1. writing will success if there is node alive for this key > > Also regardless of the write ConsistencyLevel all writes are written > to all nodes. If a target node is down HintedHandoff will queue the > write up for when the node restarts * in (6.3 you can turn off Hinted > Handoff) > > You may want to WRITE QUORUM, READ.ONE, with RF=3 you would need two > failed nodes before seeing an UnavailableException. You still have > pretty strong consistency (depending how you look at it) and fast > reads. > > Check the IRC logs Ben "schooled" me over this a couple of days ago. > -- Best Regards, Chen Xinli
