There's one specific thing that I'd point out to the author: Zookeeper and load-balancers accomplish different things. If leader-election is being used, then t

There's one specific thing that I'd point out to the author: Zookeeper and load-balancers accomplish different things. If leader-election is being used, then the cluster needs to have a single authority to enforce strict consistency in the logs. A load-balancer can only distribute load between separate nodes. If there were only a load-balancer, and no leader election, then Kafka would not be able to create logs with total orders, and you'd have a different system. (We can talk about alternative architectures, but I'm doubtful there's an alternative to leader-election that maintains the same properties.) He's complaining that Zookeeper takes 6 seconds to restore uptime in a failure, which may be improvable, but it's not really bad. If you want strict consistency, you either have a leader-election protocol, or you manually reconfigure your cluster when it fails. So, it's 6 automated seconds vs N manual minutes of labor, after your pager goes off.