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:
Jan. 26, 1999
Filed:
Nov. 29, 1995
Jack J Stiffler, Hopkinton, MA (US);
Texas Micro, Inc., Houston, TX (US);
Abstract
A mechanism for maintaining a consistent, periodically updated state in main memory without constraining normal computer operation is provided, thereby enabling a computer system to recover from faults without loss of data or processing continuity. In a typical computer system, a processor and input/output elements are connected to a main memory subsystem. A checkpoint memory element, which may include one or more buffer memories and a shadow memory, is also appended to this main memory subsystem. During normal processing, an image of data written to primary memory is captured by the checkpoint memory element. When a new checkpoint is desired, thereby establishing a consistent state in main memory to which all executing applications can safely return following a fault, the data previously captured is used to establish that checkpoint. This structure and protocol can guarantee a consistent state in main memory, thus enabling fault-tolerant operation.