US Patent 9166892 Systems and methods for event stream management

A system for managing event streams is provided that includes a volatile memory, a non-volatile memory, and a processor. The volatile memory is configured to store, for each of a plurality of event streams associated with the client device, metadata indicative of events not yet delivered to a client device and the content associated with only a most recent event of the event stream. The non-volatile memory is configured to store the content associated with each of undelivered events. The processor is configured to, upon receiving a request from the client device, retrieve from the volatile memory, without accessing the non-volatile memory, data indicative of a current state of an event stream associated with the client device. The processor is further configured to deliver the retrieved data indicative of the current state of the event stream.