It depends on if you are running embedded zk or an external zk ensemble. One leader and a replica is all you need for Solr to allow on machine to go down - but if those same machines are running zookeeper, you need 3.
You could also run zookeeper on one external machine and then it would be fine if you lost one solr node - but if you the one external zk node went down you would lose the ability to do updates until it was brought back up. - Mark On Dec 6, 2012, at 2:46 AM, Thomas Heigl <tho...@umschalt.com> wrote: > Hey all, > > I'm in the process of migrating a single Solr 4.0 instace to a SolrCloud > setup for availability reasons. > > After studying the wiki page for SolrCloud I'm not sure what the absolute > minimum setup is that would allow for one machine to go down. > > Would it be enough to have one shard with one leader and one replica? Could > this setup tolerate one of the instances going down? Or do I need three > instance because Zookeeper needs a quorum of instances? > > Cheers, > > Thomas
