Bus namespace
Created originally on Bitbucket by cdevienne (Christophe de Vienne)
The idea is to have a global namespace for all the subjects of a bus, so that several buses can share a same cluster of xbus servers.
Two buses would have no way to interact with each other. Each bus would have its own client accounts, graphs, event types... A single service would handle all the buses indifferently.
Buses could optionally use dedicated databases, although this particular setting would probably be handled by the storage implementation.