Dual counter consistency control for fault tolerant network file servers
US5713017A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 7, 1995 |
| Grant date | Jan 27, 1998 |
| Priority date | — |
| Expiry date | Jun 7, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99939
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A consistency control method for a fault tolerant file system. Data files in this fault tolerant file system are replicated on file system servers. The update request will be sent to all the file servers. However, since different servers might receive update requests in different order. The "dual-counter" scheme described in this invention is to resolve this problem. To perform an update, the client needs to obtain a sequence number from a sequencer. Two counters will be maintained by each server. The first counter is used primarily by the sequencer to sent out sequence numbers. The second counter is used by the server to keep track of the largest sequence number of requests which have been completed on the server. With the sequence numbers and the first and second counters, updates will be performed in the same order on different file servers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.