Distributed Mutual Exclusion Algorithm Research Articles

A new resource sharing protocol in the light of token-based strategy for distributed system

One of the highly researched areas in distributed system is mutual exclusion. To avoid any inconsistent state of system, more than one processes executing on different processors are not allowed to invoke their critical sections simultaneously for the purpose of resource sharing. As a solution to such resource allocation issues, token-based strategy for distributed mutual exclusion algorithms as a prime classification of solutions is one of the most popular and significant ways to handle mutual exclusion in this field. Through this research article, we propose a novel token-based distributed mutual exclusion algorithm. The proposed solution is scalable and has better results in terms of message complexity compared to existing solutions. In this proposed art of work, the numbers of messages exchange per critical section invocation are 3(⌈log N⌉ - 1), 3⌈(⌈log (N + 1) ⌉ - 1)/2⌉ and 6[⌈log (N + 1)⌉ + 2(2(-⌈log (N+1)⌉) - 1)] in case of light load, medium load and high load situations respectively.

Design and topological analysis of probabilistic distributed mutual exclusion algorithm with unbiased refined ordering

The applications of distributed computing systems are pervasive in nature involving multiple shared resources. The distributed mutual exclusion algorithms of various classes are employed to control concurrency of accessing shared resources maintaining data consistency. In general, the distributed mutual exclusion algorithms are designed based on fixed or dynamic graph structures formed by a set of processes, where the distributed mutual exclusion mechanisms are realized depending upon timestamp based ordering of events or by employing token circulation in the graph. On the contrary, in large scale heterogeneous distributed systems, an aggregate set of processes can be generated under special circumstances, where processes in a group are equally eligible to enter into critical section. In order to maintain safety and liveness properties of mutual exclusion in such cases, the probabilistic characterization as well as topological analysis of aggregate set in computing space is necessary. This paper proposes a probabilistic algorithm and its topological characterization for mutual exclusion in aggregate set of processes. The analysis of failure model of strictly ordered distributed inclusion–exclusion designs is constructed in the presence of aggregate set. The unbiased probabilistic algorithm is based on two-phased elastic randomization. The algorithm is evaluated through detailed simulation and, the related probabilistic characterization in topological subspace is evaluated. A detailed comparative analysis of the algorithm with respect to other distributed mutual exclusion algorithms is presented.

A hybrid token-based distributed mutual exclusion algorithm using wraparound two-dimensional array logical topology

In token-based distributed mutual exclusion algorithms a unique object (token) is used to grant the right to enter the critical section. For the movement of the token within the computer network, two possible methods can be considered: perpetual mobility of the token and token-asking method. This paper presents a distributed token-based algorithm scheduling mutually exclusive access to a critical resource by the processes in a distributed network. This network is composed of N nodes that communicate by message exchanges. The proposed hybrid algorithm imposes a logical structure in the form of wraparound two-dimensional array on the network. It applies the concept of perpetual mobility of the token in columns and token-asking in rows of the array. The major purpose of the algorithm is to increase the scalability property and decrease overhead due to additional communication in a system with at least one unresponded critical section request at any given time. In this status, typically, the number of message exchanges is between N and 2 N under light demand and reduces to N message exchanges under heavy demand. Therefore, it outperforms lots of well known algorithms in terms of number of messages exchanged. The algorithm satisfies safety and liveness properties.

A distributed mutual exclusion algorithm over multi-routing protocol for mobile ad hoc networks

In this paper, we propose a new architecture to solve the problem of mutual exclusion in mobile ad hoc networks (MANET). The architecture is composed of two layers: (i) a middleware layer that contains a token-based distributed mutual exclusion algorithm (DMEA) and (ii) a network layer that includes two routing forwarding strategies: one to route request messages and the other to route the token message. We also propose a request ordering policy that ensures the usual mutual exclusion properties and reduces the number of hops traversed per critical section (CS) access. The paper also addresses the problem of network partitioning and unreachable nodes. The proposed mutual exclusion algorithm is further enhanced to provide fault tolerance by preventing the loss of the token and generating a new token if the token loss event occurs. The performance complexity as well as the experimental results show that the proposed algorithm experiences low number of hops per CS access.

UN NUEVO ALGORITMO DISTRIBUIDO DE EXCLUSIÓN MUTUA QUE MINIMIZA EL INTERCAMBIO DE MENSAJES

In this paper we present a new token-based distributed mutual exclusion algorithm. The algorithm relies on two distributed dynamic structures in order to provide mutual exclusion: the “Naimi Forest” to route token requests, and the “Raymond Virtual Tree” to serve token requests. Our strategy combines the best characteristics of two algorithms cited as the most efficient in the literature concerning message traffic. We present a performance simulation study. Results show that our algorithm has better performance considering the number of message exchanged per critical section entry.

An Efficient Distributed Token-Based Mutual Exculsion Algorithm with Central Coordinator

A new distributed mutual exclusion algorithm is proposed in this paper. This algorithm is a centralized token-based algorithm. An improvement of the synchronization delay for centralized mutual exclusion in distributed systems is achieved by modifying the standard algorithm for centralized mutual exclusion by a forwarding mechanism that allows tokens to be passed directly between requesters instead of always going through a centralized coordinator. Performance metrics such as synchronization delay, messages per request, and response time under light and heavy loads, are presented. Analysis shows that this algorithm outperforms existing algorithms and its performance is close to the lower bounds of these metrics.

An Efficient Distributed Token-Based Mutual Exculsion Algorithm with Central Coordinator

A new distributed mutual exclusion algorithm is proposed in this paper. This algorithm is a centralized token-based algorithm. An improvement of the synchronization delay for centralized mutual exclusion in distributed systems is achieved by modifying the standard algorithm for centralized mutual exclusion by a forwarding mechanism that allows tokens to be passed directly between requesters instead of always going through a centralized coordinator. Performance metrics such as synchronization delay, messages per request, and response time under light and heavy loads, are presented. Analysis shows that this algorithm outperforms existing algorithms and its performance is close to the lower bounds of these metrics.

A Quorum-Based Self-Stabilizing Distributed Mutual Exclusion Algorithm

In this paper, we present a self-stabilizing quorum-based distributed mutual exclusion algorithm. Our algorithm is designed for an asynchronous message-passing model. The algorithm scales well since it has constant synchronization delay and its message complexity is proportional to the square root of the number of processes in the system. The algorithm tolerates message loss. The algorithm places few assumptions on timeouts needed for its implementation. All this allows for a ready implementation of the algorithm on practical distributed architectures.

JDM: BUILDING DISTRIBUTED SYNCHRONIZATION SUPPORT INTO JAVA

The monitor concept has been widely used in a concurrent programming environment for implicitly ensuring mutual exclusion and explicitly achieving process synchronization. It has also been extended to support high-level distributed programming. In this paper, we present JDM, a distributed monitor construct in Java for programming large-scale distributed systems. The distributed monitor construct is based on a well-know tree-based distributed mutual exclusion algorithm proposed by K. Raymond. To increase scalability of the construct, a two-level system architecture is developed, where the node level controls the access to the system-wide shared resources using Raymond's algorithm and the process level synchronizes local processes based on the local monitor concept. An object-oriented design of the system architecture is presented. Implementation and results of performance evaluation are reported and factors that influence the performance of the construct are discussed.

A mutual exclusion algorithm for ad hoc mobile networks

A fault-tolerant distributed mutual exclusion algorithm that adjusts to node mobility is presented, along with proof of correctness and simulation results. The algorithm requires nodes to communica...

Using Logical Rings to Solve the Distributed Mutual Exclusion Problem with Fault Tolerance Issues

In this paper, we investigate distributed mutual exclusion algorithms and delineate the features of a new distributed mutual exclusion algorithm. The basis of the algorithm is the logical ring structure employed in token-based mutual exclusion algorithms. Specifically, there exists dynamic properties of the logical ring that, given certain restrictions regarding message traffic flow, passively give useful information about the location of the token. Effectively, the algorithm demonstrates a type of “intelligent routing” that identifies useful shortcuts in the routing of the token. The result is a reduction in the total number of messages exchanged prior to the execution of the critical section as compared to the algorithm proposed by Fu and Tzeng l3r. Furthermore, the algorithm allows for an increased degree of fairness in a lightly loaded system than that allowed by Fu and Tzeng's algorithm. The paper also addresses failure recovery issues.

A Simulation Study on Distributed Mutual Exclusion

In the problem of mutual exclusion, concurrent access to a shared resource using a structural program abstraction called acritical section(CS) must be synchronized such that at any time only one process can enter the CS. In a distributed system, due to the lack of both a shared memory and a global clock, and due to unpredictable message delay, the design of a distributed mutual exclusion algorithm that is free from deadlock and starvation is much more complex than that in a centralized system. Based on different assumptions about communication topologies and a widely varying amount of information maintained by each site about other sites, several distributed mutual exclusion algorithms have been proposed. In this paper, we suvrey and analyze several well-known distributed mutual exclusion algorithms according to their related characteristics. We also compare the performance of these algorithms by a simulation study. Finally, we present a comparative analysis of these algorithms.

Message-efficient distributed mutual exclusion incorporating the ‘least recently used’ fairness criterion

The fairness criterion is a crucial attribute of distributed mutual exclusion algorithms. This criterion determines for how long a node, which has issued a request for executing a critical section, has to wait. All solutions to the distributed mutual exclusion problem are expected to be starvation free. Ensuring starvation freedom alone may not be sufficient in large distributed systems with online users. The least recently used (LRU) criterion is better suited for such systems. In this note, the authors have presented a distributed mutual exclusion algorithm incorporating the LRU fairness criterion. The algorithm is an improvement on Raymond's tree based algorithm for distributed mutual exclusion. The message complexity of the algorithm is low despite incorporating such a strong fairness criterion.