High availability presence engine for instant messaging

摘要

Systems for a high availability presence engine for instant messaging service comprise a plurality of presence engines for receiving presence information on users and a global table engine accessible to the plurality of presence engines. The global table engine includes user presence information and receives presence changes from the plurality of presence engines. A plurality of local tables are accessible to the plurality of presence engines and the global table engine. The plurality of local tables are configured such that each of the plurality of local tables is associated with at least one of the plurality of presence engines, and is configured to receive presence change information from the global table engine. Other systems and methods are also provided.