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. 30, 1996
Filed:
Dec. 18, 1992
Cynthia Dwork, Palo Alto, CA (US);
Joseph Y Halpern, Cupertino, CA (US);
Hovey R Strong, Jr, San Jose, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method and apparatus are disclosed for managing tasks in a network of processors. After a period of time has elapsed, during which the processors of the network have been executing tasks allocated to them, the processors exchange views as to which pending tasks have or have not been completed. The processors reach a consensus as to the overall state of completion of the pending tasks. In a preferred embodiment, the processors exchange views and update their views based on the views received from the other processors. A predetermined condition determines that a consensus has been reached. The predetermined condition is preferably two sets of exchanges in which a processor has received messages from the same set of other processors. Alternatively, the condition is an exchange which does not result in any updates to a processor's view. A processor which has not sent a view as part of an exchange is deemed to have crashed, and the tasks previously allocated to crashed processors are assumed not to have been completed. All pending tasks, including those previously allocated but not completed, are then allocated. Preferably, allocation is based on an estimation that approximately the same time will be required for each processor to complete its allocated tasks. Based on this estimation, a time is scheduled for the next exchange of views, and the processors then resume executing their allocated tasks.