Thanks Alex for the response. Our current lines in the configuration look like this:
server.5=10.10.5.17:2182:2183:participant;10.10.5.17:2181 For the new servers is it ok for their entry to have "participant"? Or should that be something different (e.g. "follower")? ~Jared On Fri, Jul 27, 2012 at 6:20 PM, Alexander Shraer <[email protected]> wrote: > Hi Jared, > > Thanks for experimenting with this feature. > > The idea is that new servers join as "non voting followers". Which means > that they act as normal followers but the leader ignores their votes since > they are not part of the current configuration. The leader only counts > their votes during the reconfiguration itself (to make sure a quorum of the > new config is ready before the new config can be committed/activated). > Defining them as observers is not a good idea, for example in your scenario > if they were observers they wouldn't be able to participate in the > reconfiguration protocol (which is similar to the protocol for committing > any other operation in which observers don't participate) and since we > don't have a quorum of followers in the new config that can ack, > reconfiguration would throw an exception (of > KeeperException.NEWCONFIGNOQUORUM type). > Of course if you intend them to be observers in the new config you can > define them as observers since their votes are not needed during reconfig > anyway. > > You're right, the new servers must be able to connect to the old quorum. > At minimum, their file should contain the current leader, but > you can also copy the current configuration file to the new members if you > wish. > > In addition, you should add a line for the member itself, so that server F > appears in F's config file (Its not important that the other new servers > appear in F's file, but it won't hurt either, so you can do a union of old > and new if you wish). The constructor of QuorumPeer checks that the server > itself is in the configuration its started with, otherwise its not going to > run. This check has always been there, but I'm thinking of possibly > changing it in the future. > > As soon as F connects to the leader, its config file will be overwritten > with the current config file as part of the synchronization process. > > Alex > > > On Fri, Jul 27, 2012 at 10:06 AM, Jared Cantwell <[email protected] > > wrote: > >> Hi, >> >> We are testing integration with 3.5.0 and dynamic membership and I have a >> question. If I have a current set of servers in my ensemble {A,B,C,D,E} >> and I want to reconfigure the ensemble to {D,E,F,G,H}, how should the >> dynamic config file on servers F,G,H be configured on startup? Should >> they >> have the old ensemble, the new ensemble, or the union of both ensembles? >> It seems like these new servers need to know about the old quorum, but >> since they aren't part of it yet its not clear to me how they should be >> configured. Should there be an intermediate configuration with F,G, and H >> as simply Observers? >> >> I can't find much documentation on this so I want to make sure I >> understand >> things correctly. >> >> Thanks! >> ~Jared >> > >
