1. A distributed hierarchical registry for device discovery and communication, the distributed hierarchical registry comprising: a plurality of registry groups at a first level of the hierarchical registry, each registry group comprising a plurality of registry servers, wherein the plurality of registry servers in a registry group provide services comprising: receiving client update information from client devices; and responding to client lookup requests from client devices; wherein the plurality of registry servers in each of the plurality of registry groups provide the services using, at least in part, a quorum consensus protocol; wherein the quorum consensus protocol defines a number of registry servers that make up a read quorum and a number of registry servers that make up a write quorum; and wherein the sum of the number of registry servers that make up the read quorum and the number of registry servers that make up the write quorum is greater than the number of registry servers in the registry group.