>> At this time there are two masters - old in part B, and new in part A.
After the network partition, there shouldn't be a leader in part B since it is a minority and will not be able to form a quorum. Thanks, Neha On Tue, Nov 26, 2013 at 6:34 AM, Maciej Smoleński <[email protected]> wrote: > Hi, > > ZooKeeper is an excellent system. The problem with ensuring only one > master among clients bothers me. > > Lets have a look at the situation when network partition happen: there > is part A (majority), and part B (minority). > Lets assume that before network partition happened the master was > connected to part B. > After the network partition, part A will elect new ZooKeeper leader, > and there will be new master elected among clients connected to part > A. > At this time there are two masters - old in part B, and new in part A. > The only solution I can think about to this problem, is to ensure that > the new master is inactive for some time - to ensure that the old > master in this time will detect that it is not connected to ZooKeeper > quorum, and will deactivate itself as a master. > This solution assumes that timers on these machines work correctly. > Is it possible to ensure only one master using ZooKeeper without > timing assumptions ? > > Thanks, > Maciej >
