Group membership discovery service

摘要

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for providing a group membership discovery service. Join requests are received from clients, including a respective group and value pair. A respective count for each received pair is updated, the count indicating a count of a join events received by servers for the pair. Notification is sent to one or more other clients that have requested such notification, wherein the notification includes a first group and value pair having a respective count that was updated for a first time. A notification is received from a server regarding a different second group and value pair received by the server and a respective count for the second group and value pair is updated.