Consensus systems are an important building block of large-scale distributed computing. Whether it is ZooKeeper, etcd, Consul, or another alternative, these systems are increasingly used in companies big and small to provide valuable features such as distributed locking and service management.

In this talk I will describe the environments and use cases where these systems make sense, as well as discussing potential alternatives to running a consensus system. I will discuss some of the challenges of using these systems in production, and provide a high level overview of the differences between two of the popular alternatives, ZooKeeper and etcd.