Re: vnodes on aws
On Thu, Dec 5, 2013 at 6:58 PM, Andrey Ilinykh ailin...@gmail.com wrote: On Thu, Dec 5, 2013 at 3:31 PM, Jayadev Jayaraman jdisal...@gmail.comwrote: Availability zones are analogous to racks not data centres . EC2 regions are equivalent to data centres. Yes, this is what I meant. I guess my question is - is possible to put row in every rack using vnodes? https://issues.apache.org/jira/browse/CASSANDRA-4123 I should point out that the existing NTS (and also the modified implementation in CASSANDRA-3881) already prevent replicas from being placed on the same host. SimpleStrategy also is fixed in the CASSANDRA-4121 patch. The first couple of paragraphs in the ticket description could probably be removed. https://issues.apache.org/jira/browse/CASSANDRA-4121 https://issues.apache.org/jira/browse/CASSANDRA-3881 =Rob
Re: vnodes on aws
Availability zones are analogous to racks not data centres . EC2 regions are equivalent to data centres. You can use vnodes if you want to deploy a cluster across multiple regions (data centres) with one availability zone per region. Each region maintains a separate ring. I don't know if you can use vnodes on multiple rack topologies however. In my case, Wlwe host a EC2 cluster with 2 fold replication and 2 zones in the same region and we don't use vnodes On Dec 5, 2013 2:32 PM, Andrey Ilinykh ailin...@gmail.com wrote: Hello everybody! We run cassandra 1.1 on ec2 instances. We use three availability zones, the replication factor is 3 also. NetworkTopologyStrategy guarantees each row is replicated in all availability zones. So, if we lost one zone quorum operations still work. We think about to upgrade to 1.2. Virtual nodes are the main reason. My understanding is - vnodes are distributed randomly, so their is no way to put every row into all availability zones. Am I right? What would be the best way to deploy vnodes across several data centers (availability zones)? Thank you, Andrey
