Good question. We addressed this in our proposal but there is a need to expand on it. IMHO we to draw a clear line to say Gossip is not a database, Gossip is not a leader election system.
We are discussing allowing the systems in the cluster to Gossip "custom" data. With that it will be a natural progression to allowing someone to build something like a leader election on top of it. However, we want to draw a careful line when we get to this point. The last thing I want is a 'crusty' lock system that does not really work a d https://aphyr.com/posts/313-strong-consistency-models tears it to shreds, or one that is more a proof of concept and can be used in production: http://stackoverflow.com/questions/14275613/concerns-about-zookeepers-lock-recipe . However Apache projects should allow people to 'scratch itches'. If we as a group want to take on leader election we will move in that direction, however recipe/feature needs to be clean, operate at scale, and not be something that is more of a liability than an asset. For example is the lock "optimistic/pessimistic"? Does it function in a split brain? and we need testable conclusions that we can validate in our release process. It can't be the academic lock recipe, that kinda works, but not with and even number of nodes, has starvation issues at scale, and sometimes two or three nodes have the lock etc :) On Wed, Jun 1, 2016 at 7:33 AM, Flavio Junqueira <[email protected]> wrote: > Hello there! > > I was reading the Gossip proposal and was wondering about its use cases. > In particular, it argues that it has some overlap with coordination systems > like ZooKeeper, so I'd be curious to hear the thoughts here on what the > specific uses cases are and I was hoping to get some clarity on where it is > a good replacement for coordination systems like zk, etcd, and others. > > The documentation mentions node discovery and cluster liveness. Are you > targeting environments in which the latency of propagating new node events > or crashed events doesn't matter? I'm also wondering if it is also part of > the motivation to use that elect a leader or implemented a distributed lock > and such. > > I hope you folks don't mind me starting this thread as I'm really curious > to learn more about where you see this project going. > > Thanks, > -Flavio > > >
