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Definition and Design of an Open Dependable Distributed Computer System Architecture

Objective

The objectives of the DELTA-4 project were to formulate, develop and demonstrate an open system, fault-tolerant, distributed computer connection architecture conforming to the OSI model. The architecture was to be capable of being configured to support a range of performances and dependabilities and to manage distributed processing, as well as offering transparent fault-tolerant and network management to the user. These features, plus the ability to connect heterogeneous computer systems into one architecture, were perceived to be directly applicable to the computer-integrated manufacturing and office systems areas. Emphasis was particularly placed on new communication techniques (optical and electrical) and concepts. A key feature of the project was to be a series of progressive demonstration prototypes, which were to form the basis for rapid commercial exploitation of the results. .
The microcomputer based prototype system consists of 3 units:
the data acquisition unit, installed inside the vehicles, that reads vehicle status;
the registration unit that stores the data, read by the data acquisition unit, in a digital cassette;
the processing unit that reads the digitised information for the whole fleet and gives statistics and the current status of the fleet.

The objectives of the project were to formulate, develop and demonstrate an open system, fault tolerant, distributed computer connection architecture conforming to the open system interconnection (OSI) model. The initial phase concentrated on the 3 main topics needed to build an open dependable distributed system. Firstly, specification and implementation of a multicast communication system (MCS) on a local area network (LAN). A prototype of the MCS was demonstrated. Secondly, specification of a high performance, cost effective network station to support the system architecture. Specifications were produced and 2 demonstrators developed. Thirdly, network management to guide the overall work on dependability. A first level of specification was achieved. These developments continued in the main phase, augmented by work on: design and development of an application support environment, to give distributed computer systems protection against local station failures via replication of tasks over the network; validation of protocols through the use of the ESTELLE formal description technique; and a study of pilot sites, to be used in the next phase. Results from these areas provided the project with a network which supports advanced protocols, a node architecture, and the global framework to integrate dependability into a distributed system.
The initial phase concentrated on the three main topics needed to build an open dependable distributed system:
-Specification and implementation of a multicast communication system on a LAN. A prototype of the MCS was demonstrated.
-Specification of high-performance, cost-effective "network station" to support the DELTA-4 system architecture. Specifications were produced and two demonstrators developed (RT Unix and RSR (Remote Service Request) prototypes).
-DELTA-4 network management to guide the overall work on dependability. A first level of specification was achieved.
These developments continued in the main phase, augmented by work on:
-design and development of an application support environment, to give distributed computer systems protection against local station failures via replication of tasks over the network
-validation of protocols through the use of the ESTELLE formal description technique (see work carried out in projects 410, SEDOS, and 1265, SEDOS DEMO
-study of pilot sites, to be used in the next phase.
Results from these areas provided the project with:
-a network which supports advanced protocols
-a node architecture
-the global framework to integrate dependability into a distributed system.
Exploitation
The interconnection equipment for heterogeneous systems delivered by this project is particularly relevant for distributed applications in computer-integrated manufacturing and office systems.
Product marketing is planned by Bull, and Ferranti is marketing a Unix-based real-time system derived from work on this project.

Coordinator

Bull SA
Address
1 Rue De Provence
38432 Echirolles
France

Participants (11)

CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE
France
Address
Avenue Du Colonel Roche,7
31077 Toulouse
Ferranti International plc
United Kingdom
Address
Simonsway Wythenshawe
M22 5LA Manchester
Fraunhofer-Gesellschaft zur Förderung der Angewandten Forschung eV (FhG)
Germany
Address
Sebastian-kneipp-straße 12-14
76131 Karlsruhe
Gesellschaft für Mathematik und Datenverarbeitung mbH
Germany
Address
Hardenbergplatz 2
10623 Berlin
INESC-INSTITUTO DE ENGENHARIA DE SISTEMAS E COMPUTADORES
Portugal
Address
Apartado 10105, Rua Alves Redol
1017 Lisboa
Institut National Polytechnique de Grenoble
France
Address

38402 Saint-martin-d'hères
JEAN LEFEBVRE TELECOM
France
Address
31-32 Quai De Dion Bouton
92811 Puteaux
MARI Applied Technologies Ltd
United Kingdom
Address
Boldon Business Park Witney Way
NE35 9PE Boldon
NATIONAL RESEARCH COUNCIL OF ITALY
Italy
Address
Via G. Moruzzi 1
56124 Pisa
Telettra SpA
Italy
Address
Via Capo Di Lucca
40126 Bologna
Università degli Studi di Bologna
Italy
Address
Viale Risorgimento 2
40136 Bologna