From the abstract: ZooKeeper is everywhere these days. It’s a core component of the Hadoop ecosystem. Your favorite startup probably uses it internally. But as every good skeptic knows, just because something is popular doesn’t mean you should use it. In this talk I will go over the core uses of ZooKeeper in the wild and why it is suited to these use cases. I will also talk about systems that don’t use ZooKeeper and why that can be the right decision. Finally I will discuss the common challenges of running ZooKeeper as a service and things to look out for when architecting a deployment.