Accession Number:

ADA169754

Title:

Decentralized System Control.

Descriptive Note:

Final rept. Nov 81-Mar 84,

Corporate Author:

CARNEGIE-MELLON UNIV PITTSBURGH PA DEPT OF COMPUTER SCIENCE

Report Date:

1986-04-01

Pagination or Media Count:

330.0

Abstract:

The Archons project is performing research on decentralized management of operating system level resources globally for an entire computer in which physical dispersal causes variable and unknown communication delays. We are interested in a very specific form of resource management decentralization decisions are made by a team of equals who negotiate, compromise, and reach a consensus -- the objectives are improved robustness and modularity compared with conventional unilateral resource management. Making decisions thusly, despite inaccurate and incomplete information about nonlocal state, involves nondeterministic computations. The scope of this management encompasses the operating system resources of all physical nodes in the computer, unlike a network which has communicating local operating systems. Failure atomicity requires a transaction facility in the OS kernel, but the usual serialization model of data consistency is insufficient for OS use -- so, we have supplemented it with a relational one. Abstract types to be managed within a decentralized OS are different from the objects found in traditional databases, requiring innovative transaction techniques. The report focuses on fundamental issues of decentralized control ranging from investigations of decentralized resource management principles to architectural support for decentralized operating systems. A development plan for the decentralized ArchOS operating system is included. Also, the DATE decentralized algorithm simulation environment and the Archons Interim Testbed are described.

Subject Categories:

  • Computer Hardware
  • Non-Radio Communications

Distribution Statement:

APPROVED FOR PUBLIC RELEASE