Exactly right - in my case the situation was another team accidentally bringing a new ZK node with "bad" but "new" data online. Had there been network isolation

Exactly right - in my case the situation was another team accidentally bringing a new ZK node with "bad" but "new" data online. Had there been network isolation, no issues. Had there been static cluster identifiers, also no issues. It was a messy environment, and it should have been prevented by operational diligence, but my point is redis is "harder to mess up". As on on-call engineer, I'll always go with simpler, foolproof tools. Another qibble is how gnarly the client-side driver for Kafka is... I don't hate Kafka, I just don't like ZK and find redis has better tooling and a better track record at my shops :)