This is what I have done so far: A,B,C are participants C,D are observers
B,C are offline (crashed) I am trying to: 1. Remove C, D 2. Add C,D back as participants Will this work? At least in my testing (might be doing wrong) I am getting this error on the first step and hence can't get forward: Client could not connect to rests blushed quorum: giving up after 30+ seconds I am passing the original server configure string to zk's reconfig method. Thanks Printing e-mails wastes valuable natural resources. Please don't print this message unless it is absolutely necessary. Thank you for thinking green! Sent from my iPhone > On Jun 14, 2016, at 10:55 PM, Alexander Shraer <[email protected]> wrote: > > Right, a quorum of participants from the old config is required to process > any command, including reconfig, > and a quorum of participants from the new config is required for the > reconfig to even start. If there's no such connected > quorum an error NewConfigNoQuorum will be thrown. > > But there is one slightly confusing case where the error is thrown, which > is explained in the doc: when you are > converting an observer to a participant and there is no quorum in the new > config without counting that "future" participant. > So the server is connected, but since its not a participant we get the > error above. In that case, one first needs to > convert the observer to remove the observer and then add it back. The > detailed explanation is in the doc, look for > "Changing an observer into a follower". > > On Wed, Jun 15, 2016 at 1:17 AM, Camille Fournier <[email protected]> > wrote: > >> I'm finding the documentation quite confusing. I was under the impression >> that quorum of some sort was needed to do a reconfig. Can you reconfig when >> there is no quorum? >> >> *Progress guarantees:* Up to the invocation of the reconfig operation, a >> quorum of the old configuration is required to be available and connected >> for ZooKeeper to be able to make progress. Once reconfig is invoked, a >> quorum of both the old and of the new configurations must be available. >> >> *Adding servers:* Before a reconfiguration is invoked, the administrator >> must make sure that a quorum (majority) of participants from the new >> configuration are already connected and synced with the current leader. >> >> >> >> On Tue, Jun 14, 2016 at 5:35 PM, Alexander Shraer <[email protected]> >> wrote: >> >>> This is needed only in case the target config doesn't have a quorum which >>> are already followers in the old config >>> and are up. We need agreement from a quorum of the target config, but >>> observers aren't participating >>> in the voting protocol. >>> >>>> On Tue, Jun 14, 2016 at 7:35 PM, Michael Han <[email protected]> wrote: >>>> >>>> This might help: >>>> https://zookeeper.apache.org/doc/trunk/zookeeperReconfig.html section >>>> '*Changing >>>> an observer into a follower:'* >>>> "first invoke a reconfig to remove D from the configuration and then >>> invoke >>>> a second command to add it back as a participant (follower)." >>>> >>>> >>>> On Tue, Jun 14, 2016 at 8:53 AM, Nomar Morado <[email protected]> >>>> wrote: >>>> >>>>> Hi >>>>> >>>>> I was trying to promote an observer into participant when ZK loses >>>> quorum - >>>>> but it seems that it does not allow to. >>>>> >>>>> Would you know how this can be accomplished without having to recycle >>> ZK? >>>>> >>>>> I am using 3.5.0-alpha >>>>> >>>>> >>>>> Thanks. >>>> >>>> >>>> >>>> -- >>>> Cheers >>>> Michael. >>
