UML Modeling of a Protocol for Establishing Mutual Exclusion in Distributed Computer System (original) (raw)
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Comparative Study of Mutual Exclusion Algorithms in Distributed Systems
Mutual Exclusion is an important phenomenon in distributed systems. In this paper, we analyze and compare various mutual exclusion algorithms in distributed systems. In permission based mutual exclusion process waits for permission from other processes to enter into a critical section. In token based mutual exclusion, a special message called token is passed over the system and process holding the token can enter into the critical section. We present a comparative study of quorum based, token ring token asking and multiple token algorithms for mutual exclusion in distributed systems.
A Review of various Mutual Exclusion Algorithms in Distributed Environment
In computer science, mutual exclusion (MUTEX) refers to a way of making sure that if one process is using shared modifiable data or resources then the other processes will be excluded from doing the same thing at the same time. A number of mutual exclusion algorithms are available in the literature, with different performance metrics and with different techniques. The Selection for a " good " mutual exclusion algorithm is a key point. These mutual exclusion algorithms can be broadly classified into token and non-token based algorithm. This paper surveys the algorithms which have been reported in the literature for Mutual exclusion in distributed systems and their comparison.
An Algorithm for Mutual Exclusion in Computer Networks
1980
• ,J kthat the number can be contained in a fixed amount of memory by storing it as the residue of a modulus. The number of messages required to implemetit the exclusion can be reduced by using sequential node-by-node processing, by using broadcast message techniques or by sending information through timing channels. The 4eaders and writers"'-problem is solved by a simple modification of the' algorithm. The modifications necessary to make the algorithm robust are described. UNCLASSIFIED WWI Abmtract An algorithm is proposed which creates mutual exclusion in a computer network whose nodes can communicate only by messages and do not share memory. The algorithm sends only 20(N-1) messages, where N is the number of nodes in the network, per critical section invocation. This number of messages is a minimum if parallel, distributed, symmetric control is used; hence, the algorithm is optimal in this respect. The time needed to achieve mutual exclusion is also minimal under some general assumptions. Like Lamport's "bakery algorithm," unbounded sequence numbers are used to provide first-come first-served priority into the critical section. It is shown that the number can be contained in a fixed amount of memory by storing it as the residue of a modulus. The number of messages required to implement the exclusion can be reduced by using sequential node-by-node processing, by using broadcast message techniques, or by sending information through timing channels. The "readers and writers" problem is solved by a simple modification of the algorithm. The modifications necessary to make the algorithm robust are described.
Single Queue Based Algorithm for Mutual Exclusion iIn Distributed Systems
Distributed System is a class of computing systems in the field of computing where the hardware or software components of the system are located at networked locations. Computers that are the part of this system can communicate and coordinate their action only by exchange of messages in the system. Mutual exclusion is a mechanism in which multi-process can make access to the single sharable resource without affecting the integrity of the resource. The number of messages among the sites of the distributed system is one of the very prime concerned issue in analysing the performance of any algorithm. Also the amount of data structures needed in the one of prime consideration in the performance analysis of algorithm. The algorithm proposed in this paper reduces the number of messages to a large extend and also there is need of a single queue as a data structure.
Two algorithms for mutual exclusion in real-time distributed computer systems
Journal of Parallel and Distributed Computing, 1990
Two algorithms developed utilizing a priority-based event-ordering which manage mutual exclusion in distributed systemscomputer networks-are proposed. in these systems, processes communicate only by messages and do not share memory. The computer network functions either (a) in an environment requiring priorities or (b) in a real-time environment. The algorithms are based on broadcast requests and token passing service approach, but the token need not be passed if no process wishes to enter the critical section. These algorithms are fully distrihuted and are insensitive to the relative speeds of node computers and communication links. They use only N messages per critical section, where N is the number of nodes (processes). The algorithms are optimal in the sense that a symmetrical, distributed algorithm cannot use fewer messages if requests are processed by each node computer concurrently. Both algorithms ensure freedom from starvation. There are mechanisms to handle node insertion and removal, node failure, the loss of the token, the existence of more than one token, and delivery of messages out of order.
Empirical Evaluation of Mutual Exclusion Algorithms for Distributed Systems
Journal of Parallel and Distributed Computing, 2000
Mutual exclusion in distributed memory systems is realized by passing messages among sites to establish a sequence for the waiting sites to enter the critical section. We have evaluated various distributed mutual exclusion algorithms on the IBM SP2 machine and the Intel iPSCÂ860 system, with their empirical results compared in terms of such criteria as the number of message exchanges and response time. The results take into account the effects of critical section request rate, critical section duration, and system size. Our results indicate that the Star algorithm (1991, M. L. Neilsen and M. Mizuno, in``Proc. 11th Int. Conf. Distributed Computing Systems,'' pp. 354 360) achieves the shortest response time in most cases among all the algorithms on a small to medium-sized system, when sites request the critical section many times before involving any barrier synchronization. This is because (1) it requires the exchange of no more than three messages per critical section entry, and (2) contention can quickly be alleviated after several entries into
Using Logical Rings to Solve the Distributed Mutual Exclusion Problem with Fault Tolerance Issues
The Journal of Supercomputing, 2000
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
International Journal of …, 2011
This paper presents a new function-based framework for mutual exclusion algorithms in distributed systems. In the traditional classification mutual exclusion algorithms were divided in to two groups: Token-based and Permission-based. Recently, some new algorithms are proposed in order to increase fault tolerance, minimize message complexity and decrease synchronization delay. Although the studies in this field up to now can compare and evaluate the algorithms, this paper takes a step further and proposes a new function-based framework as a brief introduction to the algorithms in the four groups as follows: Token-based, Permission-based, Hybrid and K-mutual exclusion. In addition, because of being dispersal and obscure performance criteria, introduces four parameters which can be used to compare various distributed mutual exclusion algorithms such as message complexity, synchronization delay, decision theory and nodes configuration. Hope the proposed framework provides a suitable context for technical and clear evaluation of existing and future methods.
Implementing Distributed Mutual Exclusion on Multithreaded Environments: The Alien-Threads Approach
2005
We present a simple implementation of a token-based distributed mutual exclusion algorithm for multithreaded systems. Several per-node requests could be issued by threads running at each node. Our algorithm relies on special-purpose alien threads running at host processors on behalf of threads running at other processors. The algorithm uses a tree to route requests for the token. We present a performance simulation study comparing two versions of our algorithm with a known algorithm based on path reversal on trees. Results show that our algorithm performs very well under a high load of requests while obtaining acceptable performance under a light load.
A Distributed Algorithm for Mutual Exclusion in an Arbitrary Network
The Computer Journal, 1988
A distributed algorithm for mutual exclusion is presented. No particular assumptions on the network topology are required, except connectivity; the communication graph may be arbitrary. The processes communicate by using messages only and there is no global controller. Furthermore, no process needs to know or learn the global network topology. In that sense, the algorithm is more general than the mutual exclusion algorithms which make use of an a priori knowledge of the network topology (for example either ring or complete network). A proof of the correctness of the algorithm is provided. The algorithm's complexity is examined by evaluating the number of messages required for the mutual exclusion protocol.