Distributed Mutual Exclusion Research

Distributed mutual exclusion algorithm is a important theory in the design of Distributed System. In the distributed system, nodes must access to the Critical Section in the mutually exclusive way. The necessary number of the messages for accessing to Critical Section is determined by the size of quorums to a great extent. This paper introduced a new suboptimal algorithm based on greedy strategy for mutual exclusion in distributed systems and posed mathematical conditions which must meet with the greedy strategy during this algorithm executing. Furthermore, in order to shorten the time that the algorithm costs, it was proposed that the power sequence: 20,21,22,23……2i(i=[log2(n/2)]) could be used to initialize the quorums. This method was mathematically proved to meet with the greedy strategy in this paper. With the algorithm, a symmetric quorum set can be fastly get for arbitrarily given integer n. The size of the symmetric quorums is between n and 2 n . Compared with the other methods, this quorum algorithm has a higher time efficiency and the quorum generated by this algorithm is very small.