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:
Aug. 02, 2011
Filed:
May. 21, 2004
Sudhir G. Rao, Portland, OR (US);
Myung M. Bae, Pleasant Valley, NY (US);
Thomas K. Clark, Gresham, OR (US);
Douglas Griffith, Apex, NC (US);
Roger L. Haskin, Morgan Hill, CA (US);
Shah Mohammad Rezaul Islam, Tucson, AZ (US);
Felipe Knop, Lagrangeville, NY (US);
Soumitra Sarkar, Cary, NC (US);
Frank B. Schmuck, Campbell, CA (US);
Theodore B. Vojnovich, Cary, NC (US);
Yi Zhou, Pittsburgh, PA (US);
Robert Curran, West Harley, NY (US);
Sudhir G. Rao, Portland, OR (US);
Myung M. Bae, Pleasant Valley, NY (US);
Thomas K. Clark, Gresham, OR (US);
Douglas Griffith, Apex, NC (US);
Roger L. Haskin, Morgan Hill, CA (US);
Shah Mohammad Rezaul Islam, Tucson, AZ (US);
Felipe Knop, Lagrangeville, NY (US);
Soumitra Sarkar, Cary, NC (US);
Frank B. Schmuck, Campbell, CA (US);
Theodore B. Vojnovich, Cary, NC (US);
Yi Zhou, Pittsburgh, PA (US);
Robert Curran, West Harley, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
The acquisition of a lock among nodes of a divided cluster is disclosed. A method is performable by each of at least one node of the cluster. A node waits for a delay corresponding to its identifier. The node asserts intent to acquire the lock by writing its identifier to X and Y variables where another node has failed to acquire the lock. The node waits for another node to acquire the lock where the other node has written to X, and proceeds where Y remains equal to its own identifier. The node waits for another node to acquire the lock where the other node has written to a Z variable, and writes its own identifier to Z and proceeds where the other node has failed. The node writes a value to Y indicating that it is acquiring the lock, and maintains acquisition by periodically writing to Z.