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:
Nov. 17, 2020
Filed:
Apr. 18, 2016
Netapp, Inc., Sunnyvale, CA (US);
Randolph Sterns, Boulder, CO (US);
Charles Binford, Wichita, KS (US);
William Delaney, Wichita, KS (US);
Joseph Blount, Wichita, KS (US);
Keith Moyer, Wichita, KS (US);
Joseph Moore, Wichita, KS (US);
NETAPP, INC., Sunnyvale, CA (US);
Abstract
A system for tracking metadata changes and recovering from system interruptions. With host I/O, corresponding metadata incremental changes are aggregated and stored in a write-ahead log before being performed to their in-memory buffers. As those buffers are flushed, checkpoints are created and stored in the log. As the log wraps to the start, older entries are overwritten after they are freed from any remaining dependencies by newer checkpoints. If metadata entities have not created new checkpoints, they are instructed to in order to free up space for new aggregated batches and checkpoints. After an interruption, the wrap point is located in the log. From the wrap point, the log is scanned backwards to provide checkpoints to metadata entities. The log is then scanned forwards to perform changes specified by aggregated batches. The metadata entities' volatile memory states are recovered to what they were before the interruption.