The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 27, 2007
Filed:
Aug. 30, 2003
Louise E. Moser, Santa Barbara, CA (US);
Peter M. Melliar-smith, Santa Barbara, CA (US);
Louise E. Moser, Santa Barbara, CA (US);
Peter M. Melliar-Smith, Santa Barbara, CA (US);
Eternal Systems, Inc., San Jose, CA (US);
Abstract
This invention defines a method and mechanisms for maintaining a consistent group membership, based on the leader-follower strategy of Semi-Active or Passive replication. Each member of the group is assigned a rank, and a precedence, determined by the order in which it is added to the group. The Primary maintains the membership of the group, while each Backup monitors the behavior of the Primary. When a Backup detects that the Primary is faulty, the Backup announces that it is the new Primary and removes the faulty Primary from the membership of the group. The group membership algorithm disclosed here does not require a consensus decision to reconfigure the membership and effects a membership change more quickly in the common case where the Backup of lowest rank takes control as the new Primary when it determines that the existing Primary failed.