Facebook's Zookeeper Implementation on Delos (opens in new tab)

Funny, the committers were at an Amsterdam meetup last night and we were talking about ClickHouse Keeper. I don't think that's very high up the list of priorities for them right now. The focus is more on ensuring it is bombproof--we're in the "long tail" part of the deployment where you stamp out obscure edge cases in increasingly large deployments.

(I'm not a committer but have a lively interest in the topic as my company supports a couple hundred customers running on ClickHouse.)

Running ZK was pretty easy with Exhibitor (not that I’d recommend it over etcd) but it’s defunct now.

Otherwise manually managing it is crufty and ancient feeling. The API for “dynamic reconfiguration” is like something I’d expect from Oracle software in the 90s. It sucks.

My understanding is that they have different consistency models and different APIs. I think etcd might be better suited for more use-cases, but I don't think migration of existing systems is straightforward.

Some previous discussion here: https://news.ycombinator.com/item?id=18687516

I also enjoyed this lecture about zookeeper: https://www.youtube.com/watch?v=pbmyrNjzdDk

Not much they have pretty compatible feature overlap. Zookeeper pushes pretty heavily on a smart client rather than handling a lot of stuff server side. If I were to pick I'd go with etcd in a heartbeat. Every con they list on their comparison website is stuff I've personally dealt with in ZK.

https://etcd.io/docs/v3.3/learning/why/#zookeeper

It isn't open source

Firefox quarantines Facebook sites in a separate container (with its own cookies and browsing history, etc.), losing back button is an unfortunate side effect.