Patent ID: 9325789
Filing Date: 2016-04-26
CPC Classification: G06Q,H04L

Claim Text:
1. A method of selecting a server as a selected server for performing a specified function in a distributed computing system, the method comprising: identifying a group of servers in the system as selecting servers for choosing the selected server; each of the selecting servers going through a respective contention period during which said each selecting server contends to be the selected server, including each selecting server in the group sending, during the contention period of said each server, a contention message including a time stamp to all the other selecting servers; each of the selecting servers receiving the contention messages from all of the other selecting servers; the selecting servers using the time stamps of the contention messages to choose the selected server, including choosing as the selected server for performing the specified function, the one server of the group of selecting servers that has been in the distributed computing system the longest based on the time stamps in the contention messages; each of the selecting servers periodically re-sending the contention message of the selected server; and the selected server querying other servers in the distributed computing system for specified contents and transferring state only from other servers that present differences; and wherein each of the selecting servers in the group has a respective clock for keeping time; and for each of the selecting servers, there is a difference between the clock of said each selecting server and a reference time, and the contention period of said each selecting server is greater than a specified time Δt to ensure that each of the selecting servers in the group receives the contention messages from all the other selecting servers in the group during the contention period of said each selecting server for choosing the selected server.