Hosting and Discovery of Distributed Mobile Services in an XMPP Cloud

While originating as an instant messaging infrastructure, the eXtensible Messaging and Presence Protocol (XMPP) has its applications as a lightweight middleware for real-time event distribution, e.g. for mobile computing or the Internet of Things. Services based on XMPP are traditionally realized as server components with simple local registration for discovery, which is not appropriate for distributed mobile services. We present an alternative approach for distributed hosting of XMPP services, which may also be suitable for distributed mobile services. Both cases have in common that service hosting nodes may be added to and removed from the overall system at any time and furthermore, the necessary access control of registration on the discovery node. The solution only uses standardized XMPP features and extensions like roster items, roster groups, entity capabilities, and inband registration. The evaluation shows how concrete service instances can be efficiently distributed on different XMPP-enabled cloud servers.