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.

主权项

1. A computer-implemented method performed by a plurality of discovery servers, wherein each discovery server performs operations comprising:
maintaining by the discovery server a respective group name/value count for each of a plurality of group name/value pairs, each group name/value count being a count for a distinct name-value pair of a user-specified group name and value pair; receiving a Watch command on a first user-specified group name from a first client device, wherein the Watch command comprises a request to receive Join events for newly added values in the first user-specified group; receiving a first Join event from another discovery server, the first Join event including the first user-specified group name and a first value, wherein a Join event received from a particular discovery server comprises a notification of a Join command or a Join event being received by the particular discovery server; incrementing the group name/value count for the first group name and the first value in response to receiving the first Join event; determining that the group name/value count for the first group name and the first value transitioned from zero to nonzero in response to the discovery server incrementing the group name/value count for the first group name and the first value; and in response to determining that the group name/value count for the first group name and the first value transitioned from zero to nonzero in response to the discovery server incrementing the group name/value count for the first group name and the first value, sending a second Join event to the first client in response to the Watch command received from the first client on the first user-specified group name, the second Join event having the first value of the first Join event.