Yea I can reconfigure cluster manually but because I have only observers in DC2 it's not possible because I don't have transaction logs in DC2, or maybe it is?
2013/2/7 Alexander Shraer <[email protected]> > Hi, > > You can probably do this manually now, but I'll let someone else comment on > this. > > In 3.5.0 release (with ZK-107 in) you will be able to turn observers into > leader + followers and vise versa by running a simple zookeeper command. > But unfortunately not in the scenario you described. > > In your scenario, there are two possible problems that make it unsafe to > reconfigure: > - it possible that the connection between the datacenters is down and not > DC1, and therefore if DC2 independently decides > to start leading we may have "split brain" - both quorums will be > independently processing and committing operations. > - it is very possible that DC1 is down but managed to commit things before > it went > down which are unknown to DC2, and therefore if we activate DC2 we'll loose > committed state. > > You will only be able to reconfigure if a quorum (majority) of the old > configuration and a quorum of the new configuration are up and connected to > the current leader. > > Alex > > On Thu, Feb 7, 2013 at 4:24 AM, Kuba Lekstan <[email protected]> wrote: > > > Hello > > > > I'm considering situation when I have 2 data centers, In 1s DC I'm having > > leader + followers, in 2nd only observers. > > In case when my 1st DC goes down, can I somehow reconfigure observers in > > 2nd DC to leader+followers? > > > > From what I found out the observers doesn't get transaction logs from the > > leader, is there any option I could set to change this behavior? > > > > Thanks. > > >
