Hi Steph, Zookeeper is a coordination service for distributed systems. Having a quorum means that more than half of the number of nodes are up and running. This is for protection of brain splitting issue. Zookeeper is a distributed system and it may be down at any time.
Brain splitting can be explained like that: assume that there are 4 nodes of Zookeeper. 2 of them can interact with each other but cannot with other two and vice versa. Some of MFC nodes are connected to 2 of them and some of them other. For a quorum we need 4 / 2 + 1 = 3. There could be a problem for MFC nodes if it was 2 (like a split of brain). Formula is calculated like that since there can be only one subset of any set which has a size of greater than half at any time. Kind Regards, Furkan KAMACI On Wed, Aug 30, 2017 at 9:24 PM, Karl Wright <daddy...@gmail.com> wrote: > Hi Steph, > > You can configure your zookeeper however you like; there is a sample > configuration file included with MCF that works out of the box. But yes, > we do recommend a quorum count of 3 or more. > > Karl > > On Wed, Aug 30, 2017 at 2:19 PM, Steph van Schalkwyk <st...@remcam.net> > wrote: > >> Karl, >> Is there a requirement for the number of ZK for MCF? I've used ZK with >> SOLR, and the minimum quorum count is 3. >> Thanks >> Steph >> >> >> >
