Massimo Coppola

Cloud federations in contrail

Cloud computing infrastructures support dynamical and flexible access to computational, network and storage resources. To date, several disjoint industrial and academic technologies provide infrastructure level access to Clouds. Especially for industrial platforms, the evolution of de-facto standards goes together with worries about user lock-in to a platform. The Contrail project [6] proposes a federated and integrated approach to Clouds. In this work we present and motivate the architecture of Contrail federations. Contrails goal is to minimize the burden on the user and increase the efficiency in using Cloud platforms by performing both a vertical and a horizontal integration. To this end, Contrail federations play a key role, allowing users to exploit resources belonging to different cloud providers, regardless of the kind of technology of the providers and with a homogeneous, secure interface. Vertical integration is achieved by developing both the Infrastructure- and the Platform-as-a-Service levels within the project. A third key point is the adoption of a fully open-source approach toward technology and standards. Beside supporting user authentication and applications deployment, Contrail federations aim at providing extended SLA management functionalities, by integrating the SLA management approach of SLA@SOI project in the federation architecture.

Virtual Organization Support within a Grid-Wide Operating System

Despite grids popularity, virtual organizations (VOs) have yet to become a commodity technology in modern computing environments due to the complexity of managing them and difficulty of assuring user and VO isolation. Here, the authors describe the VO management approach taken by XtreemOS, a new grid operating system with native support for VOs that supports a wide range of computing resources, from clusters to mobiles. They also discuss the requirements for the VO model and management within XtreemOS and introduce an expandable VO model and a system architecture that supports it.

Components for High-Performance Grid Programming in Grid.IT

This chapter presents the main ideas of the high-performance component-based Grid programming environment of the Grid.it project. High-performance components are characterized by a programming model that integrates the concepts of structured parallelism, component interaction, compositionality, and adaptivity. We show that ASSIST, the prototype of parallel programming environment currently under development at our group, is a suitable basis to capture all the desired features of the component model in a flexible and efficient manner. For the sake of interoperability, ASSIST modules or programs are automatically encapsulated in standard frameworks; currently, we are experimenting Web Services and the CORBA Component Model. Grid applications, built as compositions of ASSIST components and possibly other existing (legacy) components, are supported by an innovative Grid Abstract Machine, that includes essential abstractions of standard middleware services and a hierarchical Application Manager (AM). AM supports static allocation and dynamic reallocation of adaptive applications according to a performance contract, a reconfiguration strategy, and a performance model.

Service and Resource Discovery supports over P2P overlays

We describe the main architecture and the design principles of the Service/Resource Discovery System (SRDS), a component of the XtreemOS Operating System. XtreemOS is a Linux extension that enables management and exploitation as single platform of computational resources provided by federated Virtual Organizations. The SRDS provides scalable and fault-tolerant directory services supporting many of the platform functionalities, ranging from dynamic resource location and job control to system and application-oriented directory services. The key challenge of the SRDS design is to provide the common metaphor of the directory service, meeting the scalability requirements of a Grid-aware Operating system, and at the same time enjoy extendability and configurability, especially with respect to the quality of service provided. The SRDS design combines different peer to peer structured overlay networks, exploiting their peculiar strengths. We describe the implementation and our design of the namespace abstraction as implemented on top of multiple overlay networks. Finally, we show test results of the SRDS on top of a subset of the Grid5000 platform.

Data Extraction and Management in Networks of Observational Health Care Databases for Scientific Research: A Comparison of EU-ADR, OMOP, Mini-Sentinel and MATRICE Strategies

Introduction: We see increased use of existing observational data in order to achieve fast and transparent production of empirical evidence in health care research. Multiple databases are often used to increase power, to assess rare exposures or outcomes, or to study diverse populations. For privacy and sociological reasons, original data on individual subjects can’t be shared, requiring a distributed network approach where data processing is performed prior to data sharing. Case Descriptions and Variation Among Sites: We created a conceptual framework distinguishing three steps in local data processing: (1) data reorganization into a data structure common across the network; (2) derivation of study variables not present in original data; and (3) application of study design to transform longitudinal data into aggregated data sets for statistical analysis. We applied this framework to four case studies to identify similarities and differences in the United States and Europe: Exploring and Understanding Adverse Drug Reactions by Integrative Mining of Clinical Records and Biomedical Knowledge (EU-ADR), Observational Medical Outcomes Partnership (OMOP), the Food and Drug Administration’s (FDA’s) Mini-Sentinel, and the Italian network—the Integration of Content Management Information on the Territory of Patients with Complex Diseases or with Chronic Conditions (MATRICE). Findings: National networks (OMOP, Mini-Sentinel, MATRICE) all adopted shared procedures for local data reorganization. The multinational EU-ADR network needed locally defined procedures to reorganize its heterogeneous data into a common structure. Derivation of new data elements was centrally defined in all networks but the procedure was not shared in EU-ADR. Application of study design was a common and shared procedure in all the case studies. Computer procedures were embodied in different programming languages, including SAS, R, SQL, Java, and C++. Conclusion: Using our conceptual framework we found several areas that would benefit from research to identify optimal standards for production of empirical knowledge from existing databases.an opportunity to advance evidence-based care management. In addition, formalized CM outcomes assessment methodologies will enable us to compare CM effectiveness across health delivery settings.

Contrail: Distributed Application Deployment under SLA in Federated Heterogeneous Clouds

Cloud computing market is in rapid expansion due to the opportunities to dynamically allocate a large amount of resources when needed and to pay only for their effective usage. However, many challenges, in terms of interoperability, performance guarantee, and dependability, should still be addressed to make cloud computing the right solution for companies. In this chapter we first discuss these challenges and then we present three components developed in the framework of the Contrail project: Contrail federation; SLA manager; and Virtual Execution Platform (VEP). These components provide solutions to guarantee interoperability in a cloud federation and to deploy distributed applications over a federation of heterogeneous cloud providers. The key to success of our solutions is the possibility to negotiate performance and security guarantees for an application and then map them on the physical resources.

AOI-cast by compass routing in Delaunay based DVE overlays

This paper presents a AOI cast strategy for P2P Distributed Environments which is exploited to notify the position updates of a peer P, i.e. its heartbeats, to all the peers located in its Area of Interest. An algorithm for the construction of a spanning tree covering all the peers is presented. The algorithm exploits the properties of Delaunay Triangulations to reduce the traffic load on the P2P overlay. The paper presents a set of formal results which hold when the AOI is a circular area and the root of the tree is at the center of the area. The algorithm is then refined to take into account possible inconsistencies among the local views of the peers due to the latency of the underlying network. A set of experimental results are presented.

Highly available and scalable grid services

Grid computing infrastructures create many new challenges related to data management. Grids are typically deployed at a large scale, and one can only expect this scale to grow even more in terms of number of machines, locations and administrative domains.

Virtual Organization Management in XtreemOS: an Overview

XtreemOS aims to build and promote a Linux based operating system to provide native Virtual Organization (VO) support in the next generation Grids. XtreemOS takes a different approach from many existing Grid middleware by: first, recognizing the fundamental role of VO in Grid computing and hence taking VO support into account from the very beginning of our design; and, second, getting around the overheads brought by layers of existing Grid middleware by enabling native VO support in the Linux operating system. This paper presents our vision of VOs in a Grid operating system and describes various aspects of VO management in our system architecture, ranging from lifecycle management, application execution management, security, to node-level enforcement mechanisms in operating system.

AOI-cast in distributed virtual environments: an approach based on delay tolerant reverse compass routing

This paper presents a novel Area Of Interest (AOI)‐cast algorithm for distributed virtual environments targeted to Delaunay‐based P2P overlays. The algorithm exploits the mathematical properties of Delaunay triangulations to build a spanning tree supporting the notification of the events generated by a peer to the other ones located in its AOI. The spanning tree is computed by the reversing compass routing, a routing algorithm proposed for geometric networks. Our approach presents a set of novel features. First, it requires only the knowledge of the peers neighbors, so that the amount of traffic load on the P2P overlay is minimized. Second, we prove that, for circular shaped AOI, the algorithm builds a spanning tree covering all and only the peers of the AOI. Finally, our approach takes into account the possible inconsistencies among the local views of the peers, because the network latency, by introducing a tolerance threshold in the reverse compass routing. We present a set of simulations considering both synthetic data and real data traces taken from a real multiplayer game, which show the effectiveness of our proposal. Copyright