A cluster of computers typically establishes a quorum, i.e., a software method for establishing agreement, to coordinate access to shared resources, such as a shared data store, in applications that must recover from the failure of one or more computers or their associated components. Prior art which...http://www.google.com.hk/patents/US7320085?utm_source=gb-gplus-share專利 US7320085 - Scalable, software-based quorum architecture
