Login Password Aphyr Blog Photography Code 2014/06/09 Distributed Systems Jepsen Networks Etcd Consul In the previous post, we discovered the potential for data loss in RabbitMQ clusters . In this oft-requested installation of the Jepsen series, we’ll look at etcd : a new contender in the CP coordination service arena. We’ll also discuss Consul ’s findings with Jepsen. Like Zookeeper, etcd is designed to store small amounts of strongly-consistent state for coordination between services. It exposes a tree of logical nodes; each identified by a string key, containing a string value, and with a version number termed an index –plus, potentially, a set of child nodes. Everything’s exposed as JSON over an HTTP API. Etcd is often used for service discovery, distributed locking, atomic broadcast, sequence numbers, and pointers to data in eventually consistent sto...