From the Queue to the Quality of Service Policy: a Middleware Implementation
1. From the Queue to the Quality of Service Policy: a Middleware Implementation Institute of Industrial Control Systems Polytechnic University of Valencia José L. Poza Juan L. Posadas José E. Simó DCAI '09. 10th-12th June, 2009. University of Salamanca (Spain) The “Queue-based Quality of Service Cycle” concept
2. Quality of Service Represents the set of those quantitative and qualitative characteristics of a distributed multimedia system necessary to achieve the required functionality of an application [Vogel et al., 1995] Set of service requirements to be met by the network while transporting a flow [Crawley et al., 1998] The collective effect of service performance, which determines the degree of satisfaction of a user of the service [ITU-T, 1994] Quantitative and qualitative characteristics Required functionality Service requirements Collective effect Performance Satisfaction
4. Required functionality Queue-based system Queue-based components Parameterized system Based on quantitative parameters Standardized parameters Quantitative characteristics Qualitative characteristics
5. Architecture DDS (OMG) Parameterized objects Queue-based objects All objects inherit the QoS characteristics
7. Quality of Service cycle 1. The Queue provides the simple parameters. 2. From queue parameters, component can obtain the QoS parameters 3. QoS parameters are analyzed and combined. The result determines the compliance of the user-defined requirements. 4. If the result is out of limits, the policy acts on the concretes message queues
8. Collective effect Each single component contributes with a small part of the final component QoS values. Components don’t requires a global QoS formula.
11. Conclusions QoS is based on the DDS model Qualitative parameters based on message queue Quantitative parameters Based on the composition of the quantitative parameters Requirements feedback the message queue Predict temporal aspects to agents Know the message flow to each component of a control algorithm Defining the values of the QoS parameters, a system can self-configure the behaviour of the message queues System don’t requires a global QoS formulation
12. From the Queue to the Quality of Service Policy: a Middleware Implementation Institute of Industrial Control Systems Polytechnic University of Valencia José L. Poza Juan L. Posadas José E. Simó DCAI '09. 10th-12th June, 2009. University of Salamanca (Spain) The “Queue-based Quality of Service Cycle” concept Thanks for your attention Doubts? Suggestions?