> > > If you're running multiple nodes on a single server, vnodes give you no > control over which instance has which key (whereas you can assign initial > tokens). Therefore you could have two of your three replicas on the same > physical server which, if it goes down, you can't read or write at quorum. >
Yep. You *will* have overlapping ranges on each physical server so long as Vnodes > 'number of nodes in the cluster'. > > However, can't you use the topology snitch to put both nodes in the same > rack? Won't that prevent the issue and still allow you to maintain quorum > if a single server goes down? If I have a 20-node cluster with 2 nodes on > each physical server, can I use 10 racks to properly segment my partitions? > That's a good point, yes. I'd still personally prefer the operational simplicity of simply spacing out token assignments though, but YMMV. -- ----------------- Nate McCall Austin, TX @zznate Co-Founder & Sr. Technical Consultant Apache Cassandra Consulting http://www.thelastpickle.com
