Patent ID: 9460183
Filing Date: 2016-10-04
CPC Classification: G06F

Claim Text:
1. A high availability cluster with failover capability between nodes comprising machines of said high availability cluster without split brain situations, said high availability cluster comprising: a) a number m of master candidates identified among said machines, where said number m is at least two; b) a number n of quorum machines among said machines, where said number n is at least three and is odd; c) a local area network for synchronously replicating and updating states among said number m of master candidates to maintain a current state; d) a quorum-based majority vote protocol among said quorum machines for electing a current master from among said number m of master candidates; e) a mechanism for issuing a current time-limited lease to said current master, said current time-limited lease to be measured off by a local clock belonging to said current master; f) a physical parameter for bounding a relative clock skew of said current time-limited lease to an upper bound, said relative clock skew estimated by utilizing the Network Time Protocol (NTP); g) said high availability cluster providing a service to at least one network client; wherein a failure of said current master triggers failover to a new master from among said number m of master candidates and issuance of a new time-limited lease to said new master, thereby preventing split brain situations between said master candidates.