Erwan Daubert

An eclipse modelling framework alternative to meet the models@runtime requirements

Models@Runtime aims at taming the complexity of software dynamic adaptation by pushing further the idea of reflection and considering the reflection layer as a first-class modeling space. A natural approach to Models@Runtime is to use MDE techniques, in particular those based on the Eclipse Modeling Framework. EMF provides facilities for building DSLs and tools based on a structured data model, with tight integration with the Eclipse IDE. EMF has rapidly become the defacto standard in the MDE community and has also been adopted for building Models@Runtime platforms. For example, Frascati (implementing the Service Component Architecture standard) uses EMF for the design and runtime tooling of its architecture description language. However, EMF has primarily been thought to support design-time activities. This paper highlights specific Models@Runtime requirements, discusses the benefits and limitations of EMF in this context, and presents an alternative implementation to meet these requirements.

Using MDE to Build a Schizophrenic Middleware for Home/Building Automation

In the personal or corporate spheres, the home/office of tomorrow is soon to be the home/office of today, with a plethora of networked devices embedded in appliances, such as mobile phones, televisions, thermostats, and lamps, making it possible to automate and remotely control many basic household functions with a high degree of accuracy. In this domain, technological standardization is still in its infancy, or remains fragmented. The different functionalities of the various appliances, as well as market factors, imply that the devices that control them communicate via a multitude of different protocols (KNX, LonWorks, InOne). Building a high level middleware to support all the appliances seems to be a reasonable approach. However, market factors has shown that the emergence of a unique and universal middleware is a dream. To solve this issue, we have built a new generation of schizophrenic middleware in which service access can be generated from an abstract services description. EnTiMid, our implementation of schizophrenic middleware, supports various services access models (several personalities): SOAP (Simple Object Access Protocol), UPnP and DPWS (Device Profile for WebServices). In this paper, we describe how these personalities are generated using a Model Driven Engineering approach and discuss the benefits of our approach in the context of a deployment of new services at the city level.

Dissemination of reconfiguration policies on mesh networks

Component-based platforms are widely used to develop and deploy distributed pervasive system that exhibit a high degree of dynamicity, concurrency, distribution, heterogeneity, and volatility. This paper deals with the problem of ensuring safe yet efficient dynamic adaptation in a distributed and volatile environment. Most current platforms provide capabilities for dynamic local adaptation to adapt these systems to their evolving execution context, but are still limited in their ability to handle distributed adaptations. Thus, a remaining challenge is to safely propagate reconfiguration policies of component-based systems to ensure consistency of the architecture configuration models over a dynamic and distributed system. In this paper we implement a specific algorithm relying on the models at runtime paradigm to manage platform independent models of the current system architecture and its deployed configuration, and to propagate reconfiguration policies. We evaluate a combination of gossip-based algorithms and vector clock techniques that are able to propagate these policies safely in order to preserve consistency of architecture configuration models among all computation nodes of the system. This evaluation is done with a test-bed system running on a large size grid network.

Multitier Diversification in Web-Based Software Applications

Web application development benefits massively from modular architectures and reuse. This excellent software engineering practice is also the source of a new form of monoculture in application-level co de, which creates a potential risk for dependability. Researchers propose using software diversification in multiple components of Web applications to reconcile the tension between reuse and dependability. This article identifies key enablers for the effective diversification of software, especially at the application-code level. Its possible to combine different software diversification strategies, from deploying different vendor solutions to fine-grained code transformations, to provide different forms of protection.

Scapegoat: An Adaptive Monitoring Framework for Component-Based Systems

Modern component frameworks support continuous deployment and simultaneous execution of multiple software components on top of the same virtual machine. However, isolation between the various components is limited. A faulty version of any one of the software components can compromise the whole system by consuming all available resources. In this paper, we address the problem of efficiently identifying faulty software components running simultaneously in a single virtual machine. Current solutions that perform permanent and extensive monitoring to detect anomalies induce high overhead on the system, and can, by themselves, make the system unstable. In this paper we present an optimistic adaptive monitoring system to determine the faulty components of an application. Suspected components are finely instrumented for deeper analysis by the monitoring system, but only when required. Unsuspected components are left untouched and execute normally. Thus, we perform localized just-in-time monitoring that decreases the accumulated overhead of the monitoring system. We evaluate our approach against a state-of-the-art monitoring system and show that our technique correctly detects faulty components, while reducing overhead by an average of 80%.

ScapeGoat: Spotting Abnormal Resource Usage in Component-based Reconfigurable Software Systems

Modern component frameworks support continuous deployment and simultaneous execution of multiple software components on top of the same virtual machine. However, isolation between the various components is limited. A faulty version of any one of the software components can compromise the whole system by consuming all available resources. In this paper, we address the problem of efficiently identifying faulty software components running simultaneously in a single virtual machine. Current solutions that perform permanent and extensive monitoring to detect anomalies induce high overhead on the system, and can, by themselves, make the system unstable. In this paper we present an optimistic adaptive monitoring system to determine the faulty components of an application. Suspected components are finely analyzed by the monitoring system, but only when required. Unsuspected components are left untouched and execute normally. Thus, we perform localized just-in-time monitoring that decreases the accumulated overhead of the monitoring system. We evaluate our approach on two case studies against a state-of-the-art monitoring system and show that our technique correctly detects faulty components, while reducing overhead by an average of 93%.

Designing and evolving distributed architecture using kevoree

Modern software applications are distributed and often operate in dynamic contexts, where requirements, assumptions about the environment, and usage profiles continuously change. These changes are difficult to predict and to anticipate at design time. The running software system should thus be able to react on its own, by dynamically adapting its behavior, in order to sustain a required quality of service. A key challenge is to provide the system with the necessary flexibility to perform self-adaptation, without compromising dependability. Models@Runtime is an emerging paradigm aiming at transferring traditional modeling activities (focusing on quality, verification, and so on) performed by humans, to the running system. In this trend, Kevoree provides a models@ runtime platform to design heterogeneous, distributed and adaptive applications based on the component based software engineering paradigm. At the end of this tutorial, applicants will be able to develop and assemble new components and communication channel to design complex self-adaptable distributed architectures by reusing existing piece of code.