Aaron - I read about the virtual nodes at http://www.datastax.com/dev/blog/virtual-nodes-in-cassandra-1-2
On Tue, Aug 6, 2013 at 4:49 AM, Richard Low <rich...@wentnet.com> wrote: > On 6 August 2013 08:40, Aaron Morton <aa...@thelastpickle.com> wrote: > >> The reason for me looking at virtual nodes is because of terrible >> experiences we had with 0.8 repairs and as per documentation (an logically) >> the virtual nodes seems like it will help repairs being smoother. Is this >> true? >> >> I've not thought too much about how they help repair run smoother, what >> was the documentation you read ? >> > > There might be a slight improvement but I haven't observed any. The > difference might be that, because every node shares replicas with every > other (with high probability), a single repair operation does the same work > on the node it was called on, but the rest is spread out over the cluster, > rather than just the RF nodes either side of the repairing node. This > means the post-repair compaction work will take less time and the length of > time a node is loaded for during repair is less. > > However, the other benefits of vnodes are likely to be much more useful. > > Richard. >
