A dag-based algorithm for distributed mutual exclusion

Call number: LD2668 .T4 CMSC 1989 N45Master of ScienceComputing and Information Science

The Weakest Failure Detector to Solve Mutual Exclusion

Mutual exclusion is not solvable in an asynchronous message-passing system where processes are subject to crash failures. Delporte-Gallet et. al. determined the weakest failure detector to solve this problem when a majority of processes are correct. Here we identify the weakest failure detector to solve mutual exclusion in any environment, i.e., regardless of the number of faulty processes. We also show a relation between mutual exclusion and consensus, arguably the two most fundamental problems in distributed computing. Specifically, we show that a failure detector that solves mutual exclusion is sufficient to solve non-uniform consensus but not necessarily uniform consensus

Exclusion and Object Tracking in a Network of Processes

This paper concerns two fundamental problems in distributed computing---mutual exclusion and mobile object tracking. For a variant of the mutual exclusion problem where the network topology is taken into account, all existing distributed solutions make use of tokens. It turns out that these token-based solutions for mutual exclusion can also be adapted for object tracking, as the token behaves very much like a mobile object. To handle objects with replication, we go further to consider the more general $k$-exclusion problem which has not been as well studied in a network setting. A strong fairness property for $k$-exclusion requires that a process trying to enter the critical section will eventually succeed even if \emph{up to} $k-1$ processes stay in the critical section indefinitely. We present a comparative survey of existing token-based mutual exclusion algorithms, which have provided much inspiration for later $k$-exclusion algorithms. We then propose two solutions to the $k$-exclusion problem, the second of which meets the strong fairness requirement. Fault-tolerance issues are also discussed along with the suggestion of a third algorithm that is also strongly fair. Performances of the three algorithms are compared by simulation. Finally, we show how the various exclusion algorithms can be adapted for tracking mobile objects

A cluster based communication architecture for distributed applications in mobile ad hoc networks

Thesis (Master)--Izmir Institute of Technology, Computer Engineering, Izmir, 2006Includes bibliographical references (leaves: 63-69)Text in English; Abstract: Turkish and Englishx, 85 leavesIn this thesis, we aim to design and implement three protocols on a hierarchical architecture to solve the balanced clustering, backbone formation and distributed mutual exclusion problems for mobile ad hoc network(MANET)s. Our ¯rst goal is to cluster the MANET into balanced partitions. Clustering is a widely used approach to ease implemen-tation of various problems such as routing and resource management in MANETs. We propose the Merging Clustering Algorithm(MCA) for clustering in MANETs that merges clusters to form higher level of clusters by increasing their levels. Secondly, we aim to con-struct a directed ring topology across clusterheads which were selected by MCA. Lastly, we implement the distributed mutual exclusion algorithm based on Ricart-Agrawala algo-rithm for MANETs(Mobile RA). Each cluster is represented by a coordinator node on the ring which implements distributed mutual exclusion algorithm on behalf of any member in the cluster it represents. We show the operations of the algorithms, analyze their time and message complexities and provide results in the simulation environment of ns2

NFK: a novel fault-tolerant K-mutual exclusion algorithm for mobile and opportunistic ad hoc networks

[EN] This paper presents a fault-tolerant algorithm ensuring multiple resources sharing in mobile ad hoc networks (MANETs) that is able to handle the known K-mutual exclusion problem in such mobile environments. The proposed algorithm relies on a token-based strategy, and requires information about resources and their use to be carried in routing protocol control messages. This way, our solution avoids any additional exchange of messages. Furthermore, experimental results show that it offers a fast response time. Moreover, we introduce a dual-layer fault-tolerance mechanism that tolerates the faults of several sites at the same time without affecting the well functioning of the system. Simulation results also evidence the high efficiency of our proposal, which achieves reduced overhead and response delay even in the presence of critical situations where multiple simultaneous faults occur.Allaoui, T.; Yagoubi, MB.; Kerrache, CA.; Tavares De Araujo Cesariny Calafate, CM. (2019). NFK: a novel fault-tolerant K-mutual exclusion algorithm for mobile and opportunistic ad hoc networks. International Journal of Information and Communication Technology. 15(2):176-197. https://doi.org/10.1504/IJICT.2019.102479S17619715