Centralized vs. Decentralized QoS Management policy

On current operating systems, applications provide services based on a best effort policy, i.e., resources are shared out without regard for applications´ requirements. As long as there are enough resources, this resource sharing policy is satisfactory, but when resources become scarce, applications degrade their behavior without any control. This motivates the need of mechanisms to make applications adapt their behavior in a coordinated manner. This paper focuses on resource management of distributed applications. It describes centralized and decentralized policies aiming to manage the QoS by tuning the use of resources. Experiments compare these policies with each other according to QoS parameters and execution contexts.