Maintaining data consistency in mirrored cluster storage systems with write-back cache
US8244999B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 2011 |
| Grant date | Aug 14, 2012 |
| Priority date | — |
| Expiry date | Mar 14, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/2082
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Techniques for maintaining mirrored storage cluster data consistency on systems with write back cache can employ write-intent logging and periodic log clearing. The techniques can track any outstanding I/Os, data in caches, and data that has gone out of sync between mirrored nodes due to link failures. The techniques can ensure that a power failure on any of the storage nodes does not result in inconsistent data among the storage nodes. The techniques can use gate bitmaps to log outstanding I/Os. The gate bitmaps may be periodically cleared. The clearing period may be selected as to allow enough time for all caches to be flushed and for all synchronizing I/Os to complete. Efficient queuing of I/O requests in conjunction with the efficient operation of multiple gate bitmaps can reduce performance impacts of the gating or logging operations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.