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:
Apr. 22, 2003
Filed:
Sep. 13, 1999
Richard Andrew Golding, San Francisco, CA (US);
Elizabeth Lynn Borowsky, Brookline, MA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A distributed data storage system is provided with a mechanism for determining data storage resource availability during data system failures. When a partition occurs, a coordinator requests all reachable replicas to begin a new epoch and each replica responds with its most recent epoch number and the list of replicas that it believes were active in that epoch. From the responses, the coordinator finds the maximum epoch number and the list of replicas in that epoch is taken as the list from which a quorum must be drawn. The coordinator establishes a quorum when, for each byte in the virtual store, the coordinator receives responses from more than half of the replicas for that byte. The coordinator then determines resource availability and sends out a message to all the reachable replicas with a new epoch number greater than the previous epoch number and the list of replicas active in this new epoch. The replicas receive this message, record the epoch number and the list of replicas, and proceed.