Section: New Results

Control for adaptive systems: Discrete control for adaptive and reconfigurable systems

Participants : Eric Rutten, Noël De Palma, Olivier Gruber, Fabienne Boyer, Xin An, Soguy Mak-Kare Gueye.

The goal of this work is to apply control techniques based on the behavioral model of reactive automata and the algorithmic techniques of discrete controller synthesis. We adopt the synchronous approach to reactive systems, and use an associated effective controller synthesis tool, Sigali, developed at Inria Rennes. We are exploring several target application domains, where we expect to find commonalities in the control problems, and variations in the definitions of configurations, and in the criteria motivating adaptation.

This year, we have started investigating the application of discrete controller synthesis to various problems in computer systems management and administration. The increasing complexity of computer systems has led to the automation of administration functions, in the form of autonomic managers. One important aspect requiring such management is the issue of energy consumption of computing systems, in the perspective of green computing. As these managers address each a specific aspect, there is a need for using several managers to cover all the domains of administration. However, coordinating them is necessary for proper and effective global administration. Such coordination is a problem of synchronization and logical control of administra- tion operations that can be applied by autonomous managers on the managed system at a given time in response to events observed on the state of this system. We therefore propose to investigate the use of reactive models with events and states, and discrete control techniques to solve this problem. In [20] , [21] , [31] , [30] , we illustrate this approach by integrating a controller obtained by synchronous programming, based on Discrete Controller Synthesis, in an autonomic system administration infrastructure. The role of this controller is to orchestrate the execution of reconfiguration operations of all administration policies to satisfy properties of logical consistency. We have applied this approach to coordinate energy-aware managers for self-optimization, self-regulation of processor frequency and self-repair.