Yes, that's the way to do it.
On Wed, Jun 15, 2011 at 9:43 PM, Selva Kumar <wwgse...@yahoo.com> wrote: > Thanks Jonathan. Can we turn off RR by READ_REPAIR_CHANCE.= 0. Please > advice. > > Selva > > ________________________________ > From: Jonathan Ellis <jbel...@gmail.com> > To: user@cassandra.apache.org > Sent: Tue, June 14, 2011 8:59:41 PM > Subject: Re: Multi data center configuration - A question on read correction > > That's just read repair sending MD5s of the data for comparison. So > net traffic is light. > > You can turn off RR but the downsides can be large. Turning it down > to say 10% can be reasonable tho. > > But again, if network traffic is your concern you should be fine. > > On Tue, Jun 14, 2011 at 8:44 PM, Selva Kumar <wwgse...@yahoo.com> wrote: >> I have setup a multiple data center configuration in Cassandra. My primary >> intention is to minimize the network traffic between DC1 and DC2. Want DC1 >> read requests be served with out reaching DC2 nodes. After going through >> documentation, i felt following setup would do. >> >> >> Replica Placement Strategy: NetworkTopologyStrategy >> Replication Factor: 3 >> strategy_options: >> DC1 : 2 >> DC2 : 1 >> endpoint_snitch: org.apache.cassandra.locator.PropertyFileSnitch >> Read Consistency Level: LOCAL_QUORUM >> Write Consistency Level: LOCAL_QUORUM >> >> File: cassandra-topology.properties >> # Cassandra Node IP=Data Center:Rack >> 10.10.10.149=DC1:RAC1 >> 10.10.10.150=DC1:RAC1 >> 10.10.10.151=DC1:RAC1 >> >> 10.20.10.153=DC2:RAC1 >> 10.20.10.154=DC2:RAC1 >> # default for unknown nodes >> default=DC1:RAC1 >> >> Question I have: >> 1. Created a java program to test. It was querying with consistency level >> LOCAL_QUORUM on a DC1 node. Read count(Through cfstats) on the DC2 node >> showed read happened there too. Is it because of read correction?. Is >> there >> way to avoid doing read correction in DC2 nodes, when we query DC1 nodes. >> >> Thanks >> Selva > > > > -- > Jonathan Ellis > Project Chair, Apache Cassandra > co-founder of DataStax, the source for professional Cassandra support > http://www.datastax.com >
