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. 21, 2007
Filed:
Nov. 21, 2002
Leslie Lamport, Palo Alto, CA (US);
Aamer Hydrie, Seattle, WA (US);
Demetrios Achlioptas, Seattle, WA (US);
Leslie Lamport, Palo Alto, CA (US);
Aamer Hydrie, Seattle, WA (US);
Demetrios Achlioptas, Seattle, WA (US);
Microsoft Corporation, Redmond, WA (US);
Abstract
New information is introduced to a distributed system at many places. The information impacts data that is replicated throughout the system. The replicas of the data must be synchronized so that changes to the system are accurately reflected. One solution to the synchronized replica problem is a state machine approach. In such an approach, the computers of the network each maintain their own data, which is kept in the same state as the data of the other computers by processing the identical commands in the identical order. To ensure that all commands are executed in the same order, a lead process is given the task of assigning command sequence numbers. However, using a single lead process introduces a bottleneck in the distributed system by requiring that all commands to change data go through the lead process to be assigned an execution order. The invention divides the command ordering among multiple lead processes. Each lead process assigns command sequence numbers that are ordered with respect to other lead process but which do not conflict with the command sequence numbers assigned by the other leader processes.