Thanks. So there is not any way to ask the quorum service who is the leader? Polling of the flowers can not indicate who is the leader? On Mar 30, 2014 2:09 AM, "Kanak Biscuitwala" <[email protected]> wrote:
> If you use ZK directly, one way to do it is to have the leader to write a > znode when it becomes leader to basically announce that it has become the > leader. This should be an ephemeral node and it should be removed by the > leader before it relinquishes leadership. > > If you use Helix, you can use RoutingTableProvider or watch the external > view and that will tell you exactly who the leader is. > ________________________________ > > Date: Sun, 30 Mar 2014 00:37:15 +0200 > > Subject: RE: Comparison question > > From: [email protected] > > To: [email protected] > > > > > > Thanks a lot for fast turnaround response. > > I agree with you but I found out that quorum in ZK can treat leader > > election mechanism by using ServerService class. But I didn't figure > > out how to get callback in the client side when leader elected or > > polling the quorum or one of the members in the quorum who is the > > leader. > > > > On Mar 30, 2014 12:42 AM, "Kanak Biscuitwala" > > <[email protected]<mailto:[email protected]>> wrote: > > > > If you do leader election with ZooKeeper, you basically have to try to > > create have to follow the instructions in this recipe: > > http://zookeeper.apache.org/doc/trunk/recipes.html#sc_leaderElection -- > > this involves creating an ephemeral+sequential node, and listening for > > changes to the nodes that precede yours. > > > > If you do leader election in Helix, you configure your resource and > > participants up front, and then you're told by callback when you're > > leader, and you're told by callback when you've given up leadership. If > > you have multiple different logical entities that must have leaders, > > you can model this by just adding another partition to a resource. It's > > less error-prone this way, but you do need to spend extra time bringing > > up Helix controllers. > > ________________________________ > >> Date: Sat, 29 Mar 2014 23:05:46 +0200 > >> Subject: Fwd: Re: Comparison question > >> From: [email protected]<mailto:[email protected]> > >> To: [email protected]<mailto:[email protected]> > >> > >> > >>>> Hello Masters, > >>> > >>>> We had some internal discussion regarding the comparison among > >> Helix and Zookeeper in term of leader election mechanism. > >>>> > >>>> I'd appreciate if you could elaborate in several points about the > >> benefit of Helix against the ZooKeeper in term of Leader Election > >> mechanism. What can I do in Helix that is missing in ZooKeeprt in term > >> of Leader Election. > >>>> > >>>> Thanks in advance, > >> Erwin > >>> > >> > >> ---------- Forwarded message ---------- > >> From: "Erwin Karbasi" > > <[email protected]<mailto:[email protected]><mailto:[email protected] > <mailto:[email protected]>>> > >> Date: Mar 30, 2014 12:02 AM > >> Subject: Re: Comparison question > >> To: "kishore g" > > <[email protected]<mailto:[email protected]><mailto: > [email protected]<mailto:[email protected]>>>, > >> > > <[email protected]<mailto: > [email protected]><mailto: > [email protected]<mailto: > [email protected]>>> > >> Cc: > >> > >> > >>> Hello Masters, > >> > >>> We had some internal discussion regarding the comparison among Helix > >> and Zookeeper in term of leader election mechanism. > >>> > >>> I'd appreciate if you could elaborate in several points about the > >> benefit of Helix against the ZooKeeper in term of Leader Election > >> mechanism. What can I do in Helix that is missing in ZooKeeprt in term > >> of Leader Election. > >>> > >>> Thanks in advance, > >>> Erwin > > >
