SALTY (Self-Adaptive very Large disTributed sYstems) is an ANR funded research project (Agence Nationale de la Recherche - ANR-09-SEGI-012). It aims at providing an innovative self-managing software framework at run-time for Very-Large Scale Distributed Systems (VLSDS).
In few years, the software industry has adopted the service architectures paradigm to manage complexity, heterogeneity, adaptability and costs. The growing demand leads to the deployment of ever-larger scale systems, which reliability or performance are impaired by hardly predictable events (software faults, hardware failures, mobility, etc). Consequently, a lot of work towards software and hardware self-adaptations has been carried out and deployed into the field redundancy, resources reservation, scheduling, etc), but none of them is designed to address run-time self-adaptation of VLSDSs that consistently federate local platforms into a global distributed system to support collaborating applications.
SALTY addresses this challenge by considering the complementarities between two major trends in computer science and computer system engineering: Service Oriented Architecture (SOA) and Autonomic Computing. The scientific breakthroughs that have to be achieved in order to fill this gap are:
- Making run-time self-adaptation capabilities a first class concern into VLSDSs,
- Making self-adaptation capabilities an effective tool in the hands of software engineers.
The project has to go beyond the state-of-the-art in the domains of MDE for very large scale systems, service and component infrastructures, workflow, autonomic computing and self-adaptation, decision making processes, service-level agreement and contracting, large-scale deployment. Versatile SOA usages are considered through a general Service and Component Architecture (SCA) basis, compliant with up-to-date SOA standards. This basis will be augmented with mechanisms enabling adaptations to unexpected events and new missions required by system users such as deployment for large-scale distributed SOA-based systems, dynamic reconfiguration and contract management.
The adaptation process will be driven by a decision-making framework for distributed systems able to autonomously decide for local adaptations or more global adaptations, taking into account tradeoffs between cost, performance and availability.
The key achievement of SALTY towards the next generation of VLSDSs is the provision of a software framework, covering both design and runtime, that supports scalable self-adaptations capabilities. The framework will make usage of standard distributed reflective middleware to support the implementation of an adaptable architecture (PETALS Enterprise Service Bus and FraSCAti, its SCA support).
Two use cases covering a wide application domains are used for validating the approach and tooling propose: path-tracking of very large truck fleets via multi-means geo-positioning, and Alzheimer's disease study through huge image database analysis pipelines over a production GRID. They are emblematic (1) of the tackled issues and the technological evolutions that created them: respectively, run-time adaptation and evolution, increasing complexity of the computer based infrastructures design; (2) as well as the economical context where they lie: continuous optimization of the tradeoffs between costs related to the end-users usage, Total Cost of Ownership and Quality-of-Service of the infrastructures.The SALTY proposal is a well-balanced consortium of 4 academics:
Project Leader: Philippe Collet (UNS), Philippe dot Collet @ unice dot fr