Autonomous load sharing and mutual priority protocol using fuzzy numbers

This paper presents a fuzzy number approach to autonomous load sharing in distributed processing systems. Autonomous load sharing is a function to keep well-balanced load distribution all around the network system automatically. In a distributed processing system, it is effective in improving the throughput and the network transparency. The authors present the mutual priority protocol which realizes effective autonomous load sharing on any network architecture. This protocol is based on the mutual priority algorithm which solves assignment problem formulated with two kinds of priority orders and assignment rule for three states, i.e. “accept”, “reserve” and “reject”. According to the algorithm, the authors define T-P order for the priority level fixed by the task toward processors in the system, and P-T order for the priority level fixed by the processor to unattended tasks. In each processor, unattended tasks are in one of above three states. The “reserve” state is effective for making the load sharing function flexible against accidental or unexpected fluctuations of load in the system. The authors describe the fuzzification of the mutual priority protocol and discuss the effect of fuzzification from the view point of throughput in distributed processing systems