Accession Number : ADA140429

Title :   The Multiple Device Queueing System.

Descriptive Note : Memorandum rept.,


Personal Author(s) : Kingston,D P , III ; Muuss,M J

PDF Url : ADA140429

Report Date : Feb 1984

Pagination or Media Count : 16

Abstract : The Multiple Device Queueing System (MDQS) is designed to provide UNIX with a full function, modular, and consistent queueing system. The MDQS system has been designed with portability, expandability, robustness, and data integrity as key goals. MDQS is designed around a central queue which is managed by a single privileged daemon. Requests, delayed or immediate, are queued by non-privileged programs. Once queued, requests can be listed, modified or deleted. When the requested device or job stream becomes available, the daemon executes an appropriate server process to handle the request. Once activated, the request can still be canceled or restarted if needed. MDQS can serve as a delayed-execution/batch subsystem and replaces internally the functions of 1PR (I) and at(I) as a minimum. MDQS provides the system manager with a number of tools for managing the queueing system. Queues can be created, modified, or deleted without the loss of requests. MDQS recognizes and supports both multiple devices per queue and multiple queues per device by mapping input for a logical device to an appropriate physical output device. Anticipating the ineviktable, MDQS also provides for crash recovery. The MDQS system has been developed at the U.S.Army Ballistic Research Laboratory by Doug Kingston and Michael Nuuss to support the work of the laboratory and is available to other UNIX sites upon request. The MDQS system is designed to be compilable on a standard V7 UNIX system .

Descriptors :   *Computers, *Queueing theory, *Batch processing, *Computer programs, Batch processing, Configurations

Subject Categories : Computer Programming and Software
      Computer Hardware

Distribution Statement : APPROVED FOR PUBLIC RELEASE