Gerard Le Lann

SIRIUS: a french nationwide project on distributed data bases

ABSTRACT This paper presents SIRIUS, a french nationwide pilot project on distributed data bases ... more ABSTRACT This paper presents SIRIUS, a french nationwide pilot project on distributed data bases initiated by INRIA (Institut National de Recherche en Informatique et Automatique) in June 1976. The project SIRIUS is a collaborative project involving people from Universities, Research centres, Industry and &quot;end users&quot;. It is aimed at the development of, and the experimentation with techniques and methodologies which permit the definition, realization and exploitation of Distributed Data Base Management Systems. This paper described the original objectives, organization and achievements of the project. It gives also a listing of the principal technical documents produced by the project participants.

Real-time communication over broadcast networks: The CSMS-DCR and the DOD-CSMA-CD protocols

Novel Generic Middleware Building Blocks for Dependable Modular Avionics Systems

by Gerard Le Lann and Pascal Gula

The A3M project aimed to define basic building blocks of a middleware meeting both dependability ... more The A3M project aimed to define basic building blocks of a middleware meeting both dependability and real-time requirements for a wide range of space systems and applications. The developed middleware includes Uniform Consensus (UCS) and Uniform Coordination (UCN) protocols and two services implemented to solve two recurring problems of space applications: “distributed consistent processing under active redundancy ” and “distributed replicated data consistency, program serialization and program atomicity”. The protocols have been verified through extensive and accurate testing under the Real Time OS simulator RTSim supporting fault injections. The performances measured on a representative platform based on three LEON SPARC microprocessors interconnected with point-to-point SpaceWire links show that A3M solution may be applied to very different fields, from high performance distributed computing to satellite formation flying coordination. 1 Introduction and

Download

A general approach to real-time message scheduling over distributed broadcast channels

Proceedings 1995 INRIA/IEEE Symposium on Emerging Technologies and Factory Automation. ETFA'95, 1995

We introduce a class of real-time scheduling problems as they arise in distributed multiaccess br... more We introduce a class of real-time scheduling problems as they arise in distributed multiaccess broadcast communication channels. This class of problems is more general, hence more realistic, than the problems considered when assuming periodic or sporadic releases of messages. The authors examine the most popular algorithms and protocols, such as STDMA, polling and bus/ring token-passing. Contrary to widespread belief, the

Failure Detection with Booting in Partially Synchronous Systems

Lecture Notes in Computer Science, 2005

Unreliable failure detectors are a well known means to enrich asynchronous distributed systems wi... more Unreliable failure detectors are a well known means to enrich asynchronous distributed systems with time-free semantics that allow to solve consensus in the presence of crash failures. Implementing unreliable failure detectors requires a system that provides some synchrony, typically an upper bound on end-to-end message delays. Recently, we introduced an implementation of the perfect failure detector in a novel partially synchronous model, referred to as the Θ-Model, where only the ratio Θ of maximum vs. minimum end-to-end delay of messages that are simultaneously in transit must be known a priori (while the actual delays need not be known and not even be bounded). In this paper, we present an alternative failure detector algorithm, which is based on a clock synchronization algorithm for the Θ-Model. It not only surpasses our first implementation with respect to failure detection time, but also works during the system booting phase.

Download

Proof-Based System Engineering Using a Virtual System Model

Lecture Notes in Computer Science, 2005

This paper provides an overview of Proof-Based System Engineering (PBSE), which aims at improving... more This paper provides an overview of Proof-Based System Engineering (PBSE), which aims at improving the current practice of developing computer-based systems. PBSE is of particular relevance for safety critical applications and other systems where dependability properties are essential. This is particularly the case for applications in the aerospace domain targeted in the EC FP6 Integrated Project ASSERT. Applying PBSE both permits to eliminate most common design faults before embarking on the development of a system and maximizes reuse, which leads to significant savings in time and budgets. Particular emphasis is put on the requirements capture phase of PBSE, where a virtual system model is used as a novel means to structure the information to be captured.

Download

Fast asynchronous uniform consensus in real-time distributed systems

IEEE Transactions on Computers, 2002

... Therefore, algorithms that solve distributed fault-tolerant computing problems and scheduling... more

Download

A protocol and correctness proofs for real-time high-performance broadcast networks

Distributed Computing Systems, …, 1998

... require high-performance real-time distributed systems, and therefore high-performance real-t... more

In Pursuit of Correct Paradigms for Object-Oriented Real-Time Distributed Systems

Object-Oriented Real-Time Distributed Computing, 1999

Real time distributed applications based on object oriented technology raise many complex issues,... more Real time distributed applications based on object oriented technology raise many complex issues, most of them still open. We elaborate on the reasons why traditional paradigms, found adequate for tackling simple problems, cannot help in addressing these complex issues. A detailed illustration is given with a problem in modular avionics, which has been addressed by resorting to proof based system

Download

SIRIUS: a french nationwide project on distributed data bases

by Georges Gardarin and Gerard Le Lann

ABSTRACT This paper presents SIRIUS, a french nationwide pilot project on distributed data bases ... more ABSTRACT This paper presents SIRIUS, a french nationwide pilot project on distributed data bases initiated by INRIA (Institut National de Recherche en Informatique et Automatique) in June 1976. The project SIRIUS is a collaborative project involving people from Universities, Research centres, Industry and &quot;end users&quot;. It is aimed at the development of, and the experimentation with techniques and methodologies which permit the definition, realization and exploitation of Distributed Data Base Management Systems. This paper described the original objectives, organization and achievements of the project. It gives also a listing of the principal technical documents produced by the project participants.

Uploads

Papers by Gerard Le Lann

Log In