A structured approach to VO reconfigurations through Policies

One of the strength of Virtual Organisations is their ability to dynamically and rapidly adapt in response to changing environmental conditions. Dynamic adaptability has been studied in other system areas as well and system management through policies has crystallized itself as a very prominent solution in system and network administration. However, these areas are often concerned with very low-level technical aspects. Previous work on the APPEL policy language has been aimed at dynamically adapting system behaviour to satisfy end-user demands and - as part of STPOWLA - APPEL was used to adapt workflow instances at runtime. In this paper we explore how the ideas of APPEL and STPOWLA can be extended from workflows to the wider scope of Virtual Organisations. We will use a Travel Booking VO as example.Comment: In Proceedings FAVO 2011, arXiv:1204.579

TEXTAROSSA: Towards EXtreme scale Technologies and Accelerators for euROhpc hw/Sw Supercomputing Applications for exascale

International audienceTo achieve high performance and high energy efficiency on near-future exascale computing systems, three key technology gaps needs to be bridged. These gaps include: energy efficiency and thermal control; extreme computation efficiency via HW acceleration and new arithmetics; methods andtools for seamless integration of reconfigurable accelerators in heterogeneous HPC multi-node platforms. TEXTAROSSA aims at tackling this gap through a co-design approach to heterogeneous HPC solutions, supported by the integration and extension of HW and SW IPs, programming models and tools derived from European research

Distributed States Logic

We introduce a temporal logic to reason on global applications. First, we define a modal logic for localities that embeds the local theories of each component into a theory of the distributed states of the system. We provide the logic with a sound and complete axiomatization. Then, we extend the logic with temporal operators. The contribution is that it is possible to reason about properties that involve several components, even in the absence of a global clock, as required in an asynchronous setting. We support our proposal by working out an example, a simple secure communication system

Refining by architectural style or Architecting by refinements

In L. Vidal, A.Finkelstein, G. Spanoudakis, and A. L. Wolf (eds) Joint Proceedings of the ACM SIGSOFT 96 Workshops, Part I, 2nd Int. Software Architecture Workshop. S. Francisco, October 1996, ACM Press, pp 76-7

A Lightweight Approach to the Early Detection and Resolution of Feature Interactions

The feature interaction problem has been recognized as a general problem of software engineering, whenever one wants to reap the advantages of incremental development. In this context, a feature is a unit of change to be integrated in a new version of the system under development, and the problem is that new features may interact with the others in unexpected ways. We introduce a common abstract model, to be built during early requirement analysis in a feature oriented development. The model is common, since all the features share it, and is an abstraction of the behavioural model retaining only what is needed to characterize each feature with respect to their possible interactions. The basic constituents are the abstract resources that the features access in their operations, the access mode (read or write), and the reason of each access. Given the model, the interactions between the features are automatically detected, and the goal oriented characterization of the features provides the developers with valuable suggestions on how to qualify them as synergies or conflicts (good and bad interactions), and on how to resolve conflicts. We provide evidence of the feasibility of the approach with an extended example from the Smart Home domain. The main contribution is a lightweight state-based technique to support the developers in the early detection and resolution of the conflicts between features