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. 17, 2012
Filed:
Jan. 14, 2010
Masaki Kan, Minato-ku, JP;
Jun-ichi Yamato, Minato-ku, JP;
Yuji Kaneko, Minato-ku, JP;
NEC Corporation, Tokyo, JP;
Abstract
A replication system rapidly switches from a normal-system site to a standby-system site in the event of a problem and reliably maintains functions, and moreover, reduces drops in performance. A first site provides system functions that accompany writing and reading of data. A relay transfer device receives update information from the first site, causes completion of processes for replication in the first site, and continuously executes processes for successively transferring the update information to a second site. The second site receives the update information of the first site and applies this update information to itself to retain a replica of the data of the first site. If, when executing a write request command or a read request command to provide at least a portion of the system functions, the second site has not yet retained the most recent data that are the target of the command, the second site acquires the necessary update information and then executes the command.