How about having let's say 4 nodes on each side and make one node in one of data centers a observer. When data center with majority of the nodes go down, bounce the observer by reconfiguring it as a voting member.
You will have to revert back the observer back to being one. There will be a short outage as far as indexing is concerned but queries should continue to work and you don't have to take all the zookeeper nodes down. -- Pushkar Raste On Oct 29, 2015 4:33 PM, "Matteo Grolla" <matteo.gro...@gmail.com> wrote: > Hi Walter, > it's not a problem to take down zk for a short (1h) time and > reconfigure it. Meanwhile solr would go in readonly mode. > I'd like feedback on the fastest way to do this. Would it work to just > reconfigure the cluster with other 2 empty zk nodes? Would they correctly > sync from the nonempty one? Should first copy data from zk3 to the two > empty zk? > Matteo > > > 2015-10-29 18:34 GMT+01:00 Walter Underwood <wun...@wunderwood.org>: > > > You can't. Zookeeper needs a majority. One node is not a majority of a > > three node ensemble. > > > > There is no way to split a Solr Cloud cluster across two datacenters and > > have high availability. You can do that with three datacenters. > > > > You can probably bring up a new Zookeeper ensemble and configure the Solr > > cluster to talk to it. > > > > wunder > > Walter Underwood > > wun...@wunderwood.org > > http://observer.wunderwood.org/ (my blog) > > > > > > > On Oct 29, 2015, at 10:08 AM, Matteo Grolla <matteo.gro...@gmail.com> > > wrote: > > > > > > I'm designing a solr cloud installation where nodes from a single > cluster > > > are distributed on 2 datacenters which are close and very well > connected. > > > let's say that zk nodes zk1, zk2 are on DC1 and zk2 is on DC2 and let's > > say > > > that DC1 goes down and the cluster is left with zk3. > > > how can I restore a zk quorum from this situation? > > > > > > thanks > > > > >
