I was watching this video about how to build a highly scalable URL shortener service. https://www.youtube.com/watch?v=JQDHz72OA3c The instructor suggested that we can simply use a counter and hash that counter to provide the shortened URL. However, in a clustered environment, it wont work because if we have multiple clients that are talking to different nodes, might cause hash collision, so we need Zookeeper service to ensure there is no collision.
My question to redis experts is that if we use Redis Cluster (say on Redis Labs), do we still need Zookeeper? From what I remember reading about Redis is that INCR is atomic (but it's automic for a given node), so we might still need Zookeeper. Am I missing something?