We propose a small number of basic concepts that can be used to explain the architecture of fault-tolerant distributed systems and we discuss a list of architectural issues that we find useful to consider when designing or examining such systems. For each issue we present known solutions and design

Abstract. A distributed system is fault-tolerant if it continues to perform correctly even when a subset of the processes becomes faulty. Faulttolerance is highly desirable but often difficult to implement. In this paper, we investigate fault-tolerant synthesis, i.e., the problem of determining

Four kinds of abstraction for the design and analysis of fault-- tolerant distributed systems are discussed. These abstractions concern system messages, faults, fault--masking voting, and communication. The abstractions are formalized in higher--order logic, and are intended to facilitate

-negligible communication delays. The resulting similarities to classic large-scale distributed systems become even more accented in mission critical hardware designs that are required to operate correctly in the presence of component failures. We advocate to act on this observation and treat fault-tolerant hardware de

Algorithms for solving agreement problems can be classified in two categories: (1) those relying on failure detectors that we call FD-based, and (2) those that rely on a Group Membership Service that we call GMS-based. The paper discusses the advantages and limitations of these two approaches, and proposes an extension to the GMS-approach that combines the advantages of both approaches, without their drawbacks. This extension leads us to distinguish between timetriggered suspicions of processes and space-triggered exclusions.

This paper presents four models to demonstrate our techniques for optimizing software and hardware reliability for fault-tolerant distributed systems. The models help us find the optimal system structure while considering basic information on reliability and cost of the available software

Abstract. Four kinds of abstraction for the design and analysis of fault– tolerant distributed systems are discussed. These abstractions concern system messages, faults, fault–masking voting, and communication. The abstractions are formalized in higher–order logic, and are intended to facilitate

engineering in the context of embedded systems, demonstrates a novel idea in this domain, or overcomes a known significant challenge posed by embedded systems. In my project I examined how to select replica components in fault-tolerant systems to increase the overall reliability of the system considering

is proposed, based on the agent distributed infrastructure Lira, and enriched with statistical models for decision-making capabilities. The aim of the proposed architecture is to provide adaptive system reconfiguration, resorting to a hierarchy of resource managers to cope with fault tolerance and scalability

Algorithms for solving agreement problems can be classified in two categories: (1) those relying on failure detectors that we call FD-based, and (2) those that rely on a Group Membership Service that we call GMS-based. The paper discusses the advantages and limitations of these two approaches, and proposes an extension to the GMS-approach that combines the advantages of both approaches, without their drawbacks. This extension leads us to distinguish between timetriggered suspicions of processes and space-triggered exclusions.