International Business Machines Corporation

Harrison Scofield

Takeshi Fukumoto

Vern Lee Watts

Harley A Beier

Bruce E Naylor

Jeffrey N Stevens

Kenneth Edward Davies

Takayuki Funahasi

Mark J Kline

Terrence E Walker

Alexander T Maluta

James W Young, Jr

Walter C Geddes

A method for maintaining switchover between a backup and degrading active processor, which switchover is transparent to a terminal accessing the active processor with atomic transactions. The backup processor prepares for an outage by the active processor by synchronizing, tracking, and monitoring the active processor's log entries. When the active processor fails, the backup processor performs the necessary recovery processing and takes over user-transactions processing as the new active processor.

Data availability in restartable data base system

An expert system is provided which can be accessed by other application programs operating within any of the available operating environments in a general purpose computer system. In this architecture, an expert system consultation subsystem provides the means for performing expert consultations. Included within the expert system subsystem is a task manager which initiates and manages a plurality of concurrent consultations. Interface programming provides the capability for the expert system consultation subsystem to communicate and pass data and commands between it and other application programs operating within the computer system. Further, means are provided to allow the expert system subsystem to access data stored on database management systems.

Expert system architecture

A method is disclosed for maintaining availability of a restartable data base system where continuity of service is guaranteed by having a loosely-coupled backup processor taking over processing of a degraded active processor. The backup processor continuously tracks the activities of the active processor to ascertain data set elements updatable by the active processor. Upon switchover, images of data set elements updatable by the degraded active processor are created in the buffer of the backup processor. By making references and updates to the images, processing of the backup processor can start immediately after switchover. Upon preventing the degraded active processor from making further updates, the backup processor writes the images back to the data base.

Improving availability of a restartable staged storage data base system

Growing community of inventors

Morgan Hill, CA, United States of America

Harrison Scofield