Definition and Design of an Open Dependable Distributed System Architecture

DELTA-4 - 2252

Keywords distributed system architectures, open systems

Start Date: 03-JAN-89 / Duration: 36 months

Objectives and Approach

The aim of DELTA-4 is to formulate, develop and demonstrate an open, fault-tolerant distributed system architecture. The proposed project has direct applicability to wide application areas which include computer-integrated manufacturing, office systems, integrated information, processing systems and process control systems.

As an open system, DELTA-4 has three important properties:

Implementations based on "off-the-shelf" heterogeneous computer systems are possible; the fault-tolerant properties of the architecture are in no way dependent on the use of proprietary, fail-safe or self-checking processors.
The architecture conforms to the OSI model and implementations are able to coexist with and interwork with systems communicating by the use of current standard ISO/OSI protocols.
The dependability and distribution properties of the architecture are offered in a transparent way to the user. Both incremental dependability and incremental performance are offered on a service-by-service basis.

The proposal has both a generic component and an implementation component. The generic component is already contributing to basic concepts in the areas of dependability, multi-point communications, system administration and open distributed processing; these concepts are of value to other ESPRIT projects and to the standards community. The implementation component serves to demonstrate the validity of the concepts; the use of an experimental site and pilot sites is intended to enable their correctness to be established.

Progress and Results

Good progress has been made in the project. The MCS protocols have been defined and implemented on token ring and token bus.

An open workshop in Toulouse (October 1991) presented a number of demonstrations, including the remote banking facility implemented in the DELTA-4 technology. The workshop also demonstrated, at system level, the effectiveness of the cloning of data and processes in achieving a dependable system. Interesting results have been obtained in the area of system security based on fragmentation and scattering supported by DELTA-4 distributed technology.

More work is required on the real-time and performance aspects of this very interesting advance in distributed systems.

Exploitation

Two demonstrators were developed. The first, in a car manufacturing machine shop, handled the control of finishing and fitting out of cylinder heads. The technology was demonstrated to be suitable for general CIM applications. The other demonstrator, a distributed remote terminal banking application, as well as addressing fault tolerance also raised the security question. It was demonstrated that the fragmentation and scattering technology developed could be an effective solution to some distributed database security problems.

CONTACT POINT

Mr David Drackley
FERRANTI COMPUTER SYSTEMS LTD
Simonsway
UK - MANCHESTER M22 5LA
tel: + 44/ 61-4993355
fax: + 44/ 61-4993355
telex: 668084 G

Participants

FERRANTI COMPUTER SYSTEMS LTD - UK - C
BULL SA - F - P
INESC - P - P
CNRS-LAAS - F - P
UKAEA - UK - P
RENAULT AUTOMATION - F - P
UNIVERSITE JOSEPH
FOURIER-GRENOBLE I - F - P
SEMA METRA GROUP SA - F - P
UNIVERSITY OF NEWCASTLE-UPON-TYNE - UK - P
MARI APPLIED TECHNOLOGIES LTD - UK - P
CNR-IEI - I - P
FRAUNHOFER INSTITUT FÜR
INFORMATIONS UND DATENVERARB. - D - P
UNIBANQUE - CREDIT AGRICOLE - F - P

DELTA-4 - 2252, December 1993

please address enquiries to the ESPRIT Information Desk

html version of synopsis by Nick Cook