A feedback-based decentralised coordination model for distributed open real-time systems

Abstract

Moving towards autonomous operation and management of increasingly complex open distributed real-time systems poses very significant challenges. This is particularly true when reaction to events must be done in a timely and predictable manner while guaranteeing Quality of Service (QoS) constraints imposed by users, the environment, or applications. In these scenarios, the system should be able to maintain a global feasible QoS level while allow-ing individual nodes to autonomously adapt under different constraints of resource availability and input quality.This paper shows how decentralised coordination of a group of autonomous interdependent nodes can emerge with little communication, based on the robust self-organising principles of feedback. Positive feedback is used to reinforce the selection of the new desired global service solution, while neg-ative feedback discourages nodes to act in a greedy fashion as this adversely impacts on the provided service levels at neighbouring nodes.The proposed protocol is general enough to be used in a wide range of scenarios characterised by a high degree of openness and dynamism where coordination tasks need to be time dependent. As the reported results demon-strate, it requires less messages to be exchanged and it is faster to achieve a globally acceptable near-optimal solution than other available approaches. AbstractMoving towards autonomous operation and management of increasingly complex open distributed real-time systems poses very significant challenges. This is particularly true when reaction to events must be done in a timely and predictable manner while guaranteeing Quality of Service (QoS) constraints imposed by users, the environment, or applications. In these scenarios, the system should be able to maintain a global feasible QoS level while allowing individual nodes to autonomously adapt under different constraints of resource availability and input quality. This paper shows how decentralised coordination of a group of autonomous interdependent nodes can emerge with little communication, based on the robust self-organising principles of feedback. Positive feedback is used to reinforce the selection of the new desired global service solution, while negative feedback discourages nodes to act in a greedy fashion as this adversely impacts on the provided service levels at neighbouring nodes.The proposed protocol is general enough to be used in a wide range of scenarios characterised by a high degree of openness and dynamism where coordination tasks need to be time dependent. As the reported results demonstrate, it requires less messages to be exchanged and it is faster to achieve a globally acceptable near-optimal solution than other available approaches.

Dynamic Reconfiguration of a RGBD Sensor Based on QoS and QoC Requirements in Distributed Systems

“…One example is introduced in [ 21 ], where a QoS based framework which implements several run time adaptation mechanisms is presented. Another example is also presented in [ 22 ] where a QoS adaptation procedure is designed to fit to the different constraints of resource availability and input quality into a decentralized nodes coordinated system. Furthermore, others works have tried to apply machine intelligence tools in combination with QoS to predict failures and force adaptation before the quality decreases [ 23 ].…”