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. 19, 1994
Filed:
Sep. 16, 1993
Joseph S Insalaco, Pleasant Valley, NY (US);
Michael D Swanson, Poughkeepsie, NY (US);
International Business Machines Corp., Armonk, NY (US);
Abstract
A Shared Data Access Serialization mechanism for sharing data among a plurality of systems while maintaining data integrity. User data is maintained on a primary and optionally an alternate data store. Each data store contains a set of lock blocks, one for each system sharing the data. The contents of the lock blocks, normally a time-of-day value, indicate system ownership status of the associated data. 'Lock Rules' are disclosed for determining resource ownership, as well as a 'lock stealing' mechanism for obtaining resource ownership from a temporarily stopped system. Suffix records and check records are used to insure data integrity. Error indications deduced from inconsistent suffix and/or check records are used to trigger a data recovery mechanism, and the recovery mechanism can synchronize a primary and secondary data store without the necessity of suspending access to the primary during the synchronization process.