Sure, I mean if you constantly polled the parent node, that might get you there, but polling ZK in production is rarely a good idea. I would ask [email protected] for recommendations on how to implement leader election in pure ZooKeeper, as they would be able to give you more precise answers.
If you would like more information about how to do leader election in Helix, I will be happy to help. ________________________________ > Date: Sun, 30 Mar 2014 04:06:36 +0200 > Subject: RE: Comparison question > From: [email protected] > To: [email protected] > > > 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]<mailto:[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]<mailto:[email protected]> >> To: [email protected]<mailto:[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]><mailto:[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]><mailto:[email protected]<mailto:[email protected]>> > >>> To: > [email protected]<mailto:[email protected]><mailto:[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]>><mailto:[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]>><mailto:[email protected]<mailto:[email protected]><mailto:[email protected]<mailto:[email protected]>>>>, > >>> >> > <[email protected]<mailto:[email protected]><mailto:[email protected]<mailto:[email protected]>><mailto:[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 >> >
