I don't know, I'm a huge fan of consensus for service discovery.
It would be quite the kick in the pants if I thought that I had drained a group of machines and started some destructive maintenance on them, only to find that the eventual consistency fairy had forgotten about a couple of them, causing 500s on the site...
Multi-DC zookeeper isn't untenable. I've done it before with a quorum spread across five datacenters.
It's certainly possible to run zookeeper across multiple datacenters at scale as yelp has demonstrated, however we've elected to make a different set of tradeoffs.
Our goals include reducing operational complexity and being able to minimize the impact of node failures, i.e. quickly remove them from consideration by clients.
It would be quite the kick in the pants if I thought that I had drained a group of machines and started some destructive maintenance on them, only to find that the eventual consistency fairy had forgotten about a couple of them, causing 500s on the site...
Multi-DC zookeeper isn't untenable. I've done it before with a quorum spread across five datacenters.