Fault-tolerant Mutual Exclusion Research Articles

An Efficient Token Passing Strategy in Improved Logical Ring Structure

This paper presents a fault-tolerant mutual exclusion dual-token algorithm named DTME in distributed system. The DTME algorithm is a kind of algorithm which is based on the token ring approach. It uses two tokens which can detect each other but have different function. With a new logical ring structure, the DTME algorithm uses a novel token passing strategy to arbitrate resources shared by multi-process simultaneously. The safety, liveness and robustness properties of the DTME algorithm have been proved in this paper. In addition, we design a corresponding recovery mechanism by analyzing the impact of node failures and loss of tokens. The evaluation shows that we obtained a better result on the fault-tolerant property, average message complexity and average waiting time of the algorithm by means of simulation, compared with Jayadev Misra’s algorithm and Hoda Taheri’s algorithm. Here we also discuss few patents that are relevant to the article.

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Model repair is a formal method that aims at fixing bugs in models automatically. Typically, these models are finite state automata that can be compactly represented using guarded commands or variations thereof. The bugs in these models can be identified using traditional techniques, such as verification, testing, or runtime monitoring. However, these techniques do not assist in fixing bugs automatically. The goal in model repair is to automatically transform an input model into another model that satisfies additional properties (e.g., a property that the original model fails to satisfy). Moreover, such transformation should preserve the existing specification of the input model. In this article, we review the efforts in the past decade on developing model repair algorithms in different domains. These domains include distributed computing, fault-tolerance and self-stabilization, and real-time systems. We present the results on complexity analysis, techniques for tackling intractability of the problem and scalability, and related tools. The techniques and tools discussed in this article demonstrate the feasibility of automated synthesis of well-known protocols such as Byzantine agreement, token ring, fault-tolerant mutual exclusion, etc.

Automated model repair for distributed programs

Model repair is a formal method that aims at fixing bugs in models automatically. Typically, these models are finite state automata that can be compactly represented using guarded commands or variations thereof. The bugs in these models can be identified using traditional techniques, such as verification, testing, or runtime monitoring. However, these techniques do not assist in fixing bugs automatically. The goal in model repair is to automatically transform an input model into another model that satisfies additional properties (e.g., a property that the original model fails to satisfy). Moreover, such transformation should preserve the existing specification of the input model. In this article, we review the efforts in the past decade on developing model repair algorithms in different domains. These domains include distributed computing, fault-tolerance and self-stabilization, and real-time systems. We present the results on complexity analysis, techniques for tackling intractability of the problem and scalability, and related tools. The techniques and tools discussed in this article demonstrate the feasibility of automated synthesis of well-known protocols such as Byzantine agreement, token ring, fault-tolerant mutual exclusion, etc.

비동기적 분산 시스템에서 결함허용 상호 배제 프로토콜의 설계

This paper defines the quorum-based fault-tolerant mutual exclusion problem in a message-passing asynchronous system and determines a failure detector to solve the problem. This failure detector, which we call the modal failure detector star, and which we denote by , is strictly weaker than the perfect failure detector P but strictly stronger than the eventually perfect failure detector ◇P. The paper shows that at any environment, the problem is solvable with .

A fault tolerant mutual exclusion algorithm for mobile ad hoc networks

In this paper, we propose a permission-based message efficient mutual exclusion (MUTEX) algorithm for mobile ad hoc networks (MANETs). To reduce messages cost, the algorithm uses the “look-ahead” technique, which enforces MUTEX only among the hosts currently competing for the critical section. We propose mechanisms to handle dozes and disconnections of mobile hosts. The assumption of FIFO channel in the original “look-ahead” technique is also relaxed. The proposed algorithm can also tolerate link or host failures, using timeout-based mechanisms. Both analytical and simulation results show that the proposed algorithm works well under various conditions, especially when the mobility is high or load level is low. To our knowledge, this is the first permission-based MUTEX algorithm for MANETs.

Mutual exclusion in asynchronous systems with failure detectors

This paper considers the fault-tolerant mutual exclusion problem in a message-passing asynchronous system and determines the weakest failure detector to solve the problem, given a majority of correct processes. This failure detector, which we call the trusting failure detector, and which we denote by T , is strictly weaker than the perfect failure detector P but strictly stronger than the eventually perfect failure detector ⋄ P . The paper shows that a majority of correct processes is necessary to solve the problem with T . Moreover, T is also the weakest failure detector to solve the fault-tolerant group mutual exclusion problem, given a majority of correct processes.

On mutual exclusion in faulty distributed systems

In this paper, we present an extension of the fault-tolerant mutual exclusion algorithm of [1] to make it deadlock-free when a node requesting critical section or when a node executing its critical section fails. The proposed algorithm requires O (√ tn ) messages per critical section entry (in a network of n nodes) and O ( t √ tn ) messages when a node fails ( t − 1 is the upper bound of the node failures).