Good point. The monitor and restart trick is if you need the second DC to be voting for BCP purposes (over 3 datacenters), but otherwise an Observer is the way to go.
C On Fri, Sep 28, 2012 at 1:25 PM, Ted Dunning <[email protected]> wrote: > I am not sure of any substantial advantage to the monitor and restart trick > over observers. As far as I can tell, it mostly just makes the majority > more delicate. The minority still has to send updates through to the other > data center. > > On Fri, Sep 28, 2012 at 10:57 AM, Camille Fournier <[email protected] > >wrote: > > > If these nodes in the remote DC just need to read, you can do this via > > observers in the remote DC. If they need to write as well, you're in a > > tough spot. If most of the clients will be in one data center, I would > > favor keeping a majority of nodes in that datacenter and forcing the > master > > to be there (via monitoring and restarting as necessary), so that you can > > get votes locally and have mostly faster writes. Otherwise you're just > > going to have a slower cluster than is optimal but that's the tradeoff > for > > supporting two datacenters. > > > > C > > > > On Fri, Sep 28, 2012 at 12:13 AM, Ishaaq Chandy <[email protected]> > wrote: > > > > > Hi all, > > > We're in the process of understanding the implications of splitting > some > > of > > > the nodes of our system into a different DC. The DC will be situated > in a > > > different continent to be geographically closer to some of our clients > - > > > for network latency reasons. > > > > > > Anyway, we're trying to work out how work with our ZK cluster in this > > > scenario. The way I see it we have 2 options: > > > > > > 1. Leave our existing ZK cluster as is on our primary DC, make the > nodes > > on > > > the new DC make the hop to do comms with it > > > 2. Add a couple of new local ZK nodes to the new DC and let all them > sort > > > out the comms between them and the rest of the ZK cluster back in the > > > primary DC > > > > > > I am leaning towards the latter option but was wondering if any of you > > have > > > any insights/experiences in this area that might help us make an > informed > > > decision. > > > > > > Thanks, > > > Ishaaq > > > > > >
