Integrity of data objects used to maintain state information for shared data at a local complex
US5331673A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 1992 |
| Grant date | Jul 19, 1994 |
| Priority date | — |
| Expiry date | Mar 30, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2201/825
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Apparatus and method insuring that data objects used to maintain state information for shared data at a local central processing complex (CPC) are coherent with respect to state information maintained at a structured external storage facility (SES) over a link is valid. An error detector is attached to the CPC side of the link for detecting errors on the link, and, when an error is detected, setting a error state pending (ESP) latch to indicate that the link has failed and that the shared data in the local data object may be invalid because a message invalidating the data may not have been received by the CPC. In data processing operations, the ESP latch is interrogated by a central processor in the CPC to determine the health of the message path to the SES facility. A local cache vector reflecting the validity of the shared data in the local cache may then be interrogated to determine if the shared data in the local cache is valid. If a healthy path has continuously existed and the vector indicates that the local cache data is valid, the integrity of the data can be relied on.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.