Il mer 21 ago 2019, 17:22 Alexander Shraer <shra...@gmail.com> ha scritto:
> That's great! Thanks for sharing. > > > Added benefit is that we can also control which data center gets the > quorum > > in case of a network outage between the two. > > Can you explain how this works? In case of a network outage between two > DCs, one of them has a quorum of participants and the other doesn't. > The participants in the smaller set should not be operational at this time, > since they can't get quorum. no ? > I have recently talked about a similar problem with Norbert K. on gitter chat. We got to the conclusion that you need 3 datacenters Enrico > Thanks, > Alex > > On Wed, Aug 21, 2019 at 7:55 AM Cee Tee <c.turks...@gmail.com> wrote: > > > We have solved this by implementing a 'zookeeper cluster balancer', it > > calls the admin server api of each zookeeper to get the current status > and > > will issue dynamic reconfigure commands to change dead servers into > > observers so the quorum is not in danger. Once the dead servers > reconnect, > > they take the observer role and are then reconfigured into participants > > again. > > > > Added benefit is that we can also control which data center gets the > > quorum > > in case of a network outage between the two. > > Regards > > Chris > > > > On 21 August 2019 16:42:37 Alexander Shraer <shra...@gmail.com> wrote: > > > > > Hi, > > > > > > Reconfiguration, as implemented, is not automatic. In your case, when > > > failures happen, this doesn't change the ensemble membership. > > > When 2 of 5 fail, this is still a minority, so everything should work > > > normally, you just won't be able to handle an additional failure. If > > you'd > > > like > > > to remove them from the ensemble, you need to issue an explicit > > > reconfiguration command to do so. > > > > > > Please see details in the manual: > > > https://zookeeper.apache.org/doc/r3.5.5/zookeeperReconfig.html > > > > > > Alex > > > > > > On Wed, Aug 21, 2019 at 7:29 AM Gao,Wei <wei....@arcserve.com> wrote: > > > > > >> Hi > > >> I encounter a problem which blocks my development of load balance > > using > > >> ZooKeeper 3.5.5. > > >> Actually, I have a ZooKeeper cluster which comprises of five zk > > >> servers. And the dynamic configuration file is as follows: > > >> > > >> server.1=zk1:2888:3888:participant;0.0.0.0:2181 > > >> server.2=zk2:2888:3888:participant;0.0.0.0:2181 > > >> server.3=zk3:2888:3888:participant;0.0.0.0:2181 > > >> server.4=zk4:2888:3888:participant;0.0.0.0:2181 > > >> server.5=zk5:2888:3888:participant;0.0.0.0:2181 > > >> > > >> The zk cluster can work fine if every member works normally. > However, > > if > > >> say two of them are suddenly down without previously being notified, > > >> the dynamic configuration file shown above will not be synchronized > > >> dynamically, which leads to the zk cluster fail to work normally. > > >> I think this is a very common case which may happen at any time. If > > so, > > >> how can we resolve it? > > >> Really look forward to hearing from you! > > >> Thanks > > >> > > > > > > > > >
