An asynchronous message-passing distributed algorithm for the global critical section problem

This paper considers the global $(l,k)$-CS problem which is the problem of controlling the system in such a way that, at least $l$ and at most $k$ processes must be in the CS at a time in the network. In this paper, a distributed solution is proposed in the asynchronous message-passing model. Our solution is a versatile composition method of algorithms for $l$-mutual inclusion and $k$-mutual exclusion. Its message complexity is $O(|Q|)$, where $|Q|$ is the maximum size for the quorum of a coterie used by the algorithm, which is typically $|Q| = \sqrt{n}$.Comment: This is a modified version of the conference paper in PDAA201

(h,k)-Arbiters for h-out-of-k mutual exclusion problem

Abstracth-Out-of-k mutual exclusion is a generalization of the 1-mutual exclusion problem, where there are k units of shared resources and each process requests h(1⩽h⩽k) units at the same time. Though k-arbiter has been shown to be a quorum-based solution to this problem, quorums in k-arbiter are much larger than those in the 1-coterie for 1-mutual exclusion. Thus, the algorithm based on k-arbiter needs many messages. This paper introduces the new notion that each request uses different quorums depending on the number of units of its request. Based on the notion, this paper defines two (h,k)-arbiters for h-out-of-k mutual exclusion: a uniform (h,k)-arbiter and a (k+1)-cube (h,k)-arbiter. The quorums in each (h,k)-arbiter are not larger than the ones in the corresponding k-arbiter; consequently, it is more efficient to use (h,k)-arbiters than the k-arbiters. A uniform (h,k)-arbiter is a generalization of the majority coterie for 1-mutual exclusion. A (k+1)-cube (h,k)-arbiter is a generalization of square grid coterie for 1-mutual exclusion

Sistem Himpunan Korum dan Masalah Resolusi Konflik Terdistribusi

The aims of this study are (1) to analyze relaxation of the characteristics of distributed mutual exclusion problem of various problems of widening conflict resolution in distributed system, (2) to develop coterie set system in solving any types of conflict resolution in distributed system, (3) to analyze coterie set to solve the distributed conflict problem. The method used was literary study by collecting research materials through library journals that relevant with the subject matter i.e. quorum set system and various problems of distributed conflict resolution. The results of the research indicated that mutual exclusion (mutex) can be solved with coterie, k-mutex problem can be solved by using k-coterie, read-writer problem can be solved by using bicoteri, restricted resources problem can be solved by using (m,h,ki)-coterie. For restricted and various resources matter can be constructed with disjoint and simple uniform (m,h,k)-coterie

KETERSEDIAAN OPERASI JOIN DIPERLUAS KOTERI-k TAK-TERDOMINASI

Penelitian ini bertujuan menganalisis ketersediaan dari koteri-  mayoritas tak-terdominasi yang menggunakan operasi join diperluas yaitu penggabungkan koteri- ,  dan  masing-masing atas semesta  dan  dengan unsur tereliminasi , dimana  yang menghasilakan koteri-  tak-terdominasi  atas semesta . Metode penggabungan koteri-  mayoritas tak-terdominasi yang menggunakan operasi join diperluas menghasilkan koteri  atas . Hasil ketersediaan dari operasi join kemudian dibandingkan dengan ketersedian dengan menggunakan operasi join. Dari penelitian ini, menunjukkan bahwa ketersedian operasi join memberikan hasil yang lebih baik jika dibandingkan dengan ketersedian dari operasi join

Performance Evaluation in Energy consumption of Mobile Ad-Hoc Network to increase the Network Lifetime

MANET is self configuring network. It has many design issues like scalability, energy consumption etc.In this paper, an overview of the Distributed mutual exclusion algorithm & various enhanced variations done on distributed mutual exclusion. In DME Permission-based algorithm is used for discovering clusters of the nodes. The initial point selection effects on the results of the algorithm, in the number of clusters found and their cluster headers. Methods to enhance the Permission-based clustering algorithm are discussed. With the help of these methods increase the concurrency between the nodes, decrease the synchronization delay and decrease response time. Some enhanced variations improve the efficiency and accuracy of algorithm. Basically in all the methods the main aim is to increase the life of each node in the network or increase the battery power which will decrease the computational time. Various enhancements done on DME are collected, so by using these enhancements one can build a new hybrid algorithm which will be more efficient, accurate and less time consuming than the previous work

Quorum Based Conflict Resolution Algorithms In Distributed Systems

Mutual exclusion is one of the most fundamental issues in the study of distributed systems. The problem arises when two or more processes are competing to use a mutual exclusive resource concurrently, i.e., the resource can only be used by at most one process at a time. Synchronizations adopting quorum systems are an important class of distributed algorithms since they are gracefully and significantly tolerate process and communication failures that may lead to network partitioning. Coterie based algorithm is a typical quorum based algorithm for mutual exclusion: A process can use the resource  only if it obtains permissions from all processes in any quorum ofcoterie, and since each quorum intersects with each other and each process only issues one permission, the mutual exclusion can be guaranteed. Many quorum systems have been defined based on the relaxation of the properties of coterie system. Each of them is designed to resolve its corresponding problem, e.g., k-coterie based algorithm to resolve the k-mutual exclusion, local coterie for the generalized mutual exclusion, (h, k)-arbiter for h-out of-k resource allocation problem, etc. Therefore, design an algorithm for any distributed conflict resolution problem is only meant to define a new quorum system which can be implemented to the corresponding problem. Since most of distributed conflict resolution problems are designed based on the relaxation of the safety property of mutual exclusion, understanding the way to relaxing the safety property and its quorum system is important to study any kind of conflict resolution problem in distributed systems

Coterie Join Operation and Tree Structured k-Coteries

The coterie join operation proposed by Neilsen and Mizuno produces, from a k-coterie and a coterie, a new k-coterie. For the coterie join operation, this paper first shows 1) a necessary and sufficient condition to produce a nondominated k-coterie (more accurately, a nondominated k-semicoterie satisfying Nonintersection Property) and 2) a sufficient condition to produce a k-conterie with higher availability. By recursively applying the coterie join operation in such a way that the above conditions hold, we define nondominated k-coteries, called tree structured k-coteries, the availabilities of which are thus expected to be very high. This paper then proposes a new k-mutual exclusion algorithm that effectively uses a tree structured k-coterie, by extending Agrawal and El Abbadi's tree algoriyhm. The number of messages necessary for k processes obeying the algorithm to simultaneously enter the critical section is approximately bounded by k log (n / k) in the best case, where n is the number of processes in the system

k-coteries for tolerating network 2-Partition

Network partition, which makes it impossible for some pairs of precesses to communicate with each other, is one of the most serious network failures. Although the notion of k-coterie is introduced to design a k-mutual exclusion algorithm robust against network failures, the number of processes allowed to simultaneously access the critical section may fatally decrease once network partition occurs. This paper discusses how to construct a k-coterie such that the k-mutual exclusion algorithm adopting it is robust against network 2-partition. To this end, we introduce the notion of complemental k-coterie, and show that complemental k-coteries meet our purpose. We then give methods for constructing complemental k-coteries, and show a necessary and sufficient condition for a k-coteries to be complemental