Sure, replicationFactor=2 is fine. Solr goes to a lot of effort to avoid split-brain issues using Zookeeper.
You're confusing, I think, Solr node replication and Zookeeper. The Solr replicationFactor has nothing to do with quorum. Having 2 is the same as 3. Solr uses Zookeeper's Quorum sensing to insure that all Solr nodes have a consistent picture of the cluster. Solr will refuse to index data if _Zookeeper_ loses quorum. But whether Solr has 2 or 3 replicas is not relevant. Solr indexes data through the leader of each shard, and that keeps all replicas consistent. As far as other impacts, adding a replica will have an impact on indexing throughput, you'll have to see whether that makes any difference in your situation. This is usually on the order of 10% or so, YMMV. And this is only on the first replica you add, i.e. going from leader-only to 2 replicas costs, say, 10% on throughput, but adding yet another replica does NOT add another 10% since the leader->replica updates are done in parallel. Best, Erick On Fri, Oct 7, 2016 at 9:43 AM, Jeffery Yuan <yuanyun...@gmail.com> wrote: > We are trying to building our solr cloud servers, we want to increase > replicationFactor, but don't want to set it as 3 as we have a lot of data. > > So I am wondering whether it makes sense to set replicationFactor as 2, and > what's the impact, whether this will cause problem for replica leader > election such as split brain etc? > > Thanks > > > > -- > View this message in context: > http://lucene.472066.n3.nabble.com/Whether-replicationFactor-2-makes-sense-tp4300204.html > Sent from the Solr - User mailing list archive at Nabble.com.
