Structured and flexible gray-box composition: Application to task rescheduling for grid benchmarking

International audienceThe evolution of complex distributed software systems often requires intricate composition operations in order to adapt or add functionalities, react to unanticipated changes to security policies, or do performance improvements, which cannot be modularized in terms of existing services or components. They often need controlled access to selected parts of the implementation, e.g., to manage exceptional situations and crosscutting within services and their compositions. However, existing composition techniques typically support only interface-level (black-box) composition or arbitrary access to the implementation (gray-box or white-box composition). In this paper, we present a more structured approach to the composition of complex software systems that require invasive accesses. Concretely, we provide two contributions, we (i) present a small kernel composition language for structured gray-box composition with explicit control mechanisms and a corresponding aspect-based implementation; (ii) present and compare evolutions using this approach to gray-box composition in the context of two real-world software systems: benchmarking of grid algorithms with NASGrid and transactional replication with JBoss Cache

Structured and flexible gray-box composition using invasive distributed patterns

ISBN = {ISSN: 1646-3692}International audienceThe evolution of complex distributed software systems often requires intricate composition operations in order to adapt or add functionalities, to react to unanticipated changes, or to apply performance improvements that cannot be modularized in terms of existing services and components. These evolutions often need controlled access to selected parts of the implementation, e.g., to manage exceptional situations and crosscutting within services and their compositions. However, existing composition techniques typically support only interface-level (black-box) composition or arbitrary access to the implementation (gray-box or white-box composition). In this paper, we present a structured approach to the composition of complex software systems that require invasive modifications. Concretely, we provide three contributions: (i) we present a small kernel composition language for structured gray-box composition using invasive distributed patterns; (ii) we motivate that gray-box composition approaches should be defined and evaluated in terms of the flexibility and control they provide, a notion of degrees of invasiveness is introduced to help assess this trade-off; (iii) we apply our approach to a new case study of evolution and evaluate it in the context of two previous studies involving two real-world software systems: benchmarking of grid algorithms with NASGrid and transactional replication with JBoss Cache. As a main result, we show that gray-box composition using invasive distributed patterns allows the declarative and modular definition of evolutions of real-world applications that need moderate to high degrees of invasive modifications

Detection and resolution of aspect interactions

Aspect-Oriented Programming (AOP) promises separation of concerns at the implementation level. However, aspects are not always orthogonal and aspect interaction is an important problem. Currently there is almost no support for the detection and resolution of such interactions. The programmer is responsible for identifying interactions between conflicting aspects and implementing conflict resolution code. In this paper, we propose a solution to this problem based on a generic framework for AOP. The contributions are threefold: we present a formal and expressive crosscut language, two static conflict analyses and some linguistic support for conflict resolution

Invasive composition for the evolution of a health information system

ACM 978-1-4503-0646-1/11/03, ISBN: 978-1-4503-0646-1International audienceIn this paper we show that some of the evolution tasks in OpenMRS, a health information system, may require the invasive modification of interfaces and implementations in order to offer an appropriate modularization. We introduce a new composition framework in Java that supports the definition of expressive pattern-based invasive compositions. Fur thermore, we show that the composition framework allows us to concisely define an evolution scenario of OpenMRS that supports the consolidation of patient data from differ- ent remote instances

Vers une gestion coopérative des infrastructures virtualisées à large échelle (le cas de l'ordonnancement)

Les besoins croissants en puissance de calcul sont généralement satisfaits en fédérant de plus en plus d ordinateurs (ou noeuds) pour former des infrastructures distribuées. La tendance actuelle est d utiliser la virtualisation système dans ces infrastructures, afin de découpler les logiciels des noeuds sous-jacents en les encapsulant dans des machines virtuelles. Pour gérer efficacement ces infrastructures virtualisées, de nouveaux gestionnaires logiciels ont été mis en place. Ces gestionnaires sont pour la plupart hautement centralisés (les tâches de gestion sont effectuées par un nombre restreint de nœuds dédiés). Cela limite leur capacité à passer à l échelle, autrement dit à gérer de manière réactive des infrastructures de grande taille, qui sont de plus en plus courantes. Au cours de cette thèse, nous nous sommes intéressés aux façons d améliorer cet aspect ; l une d entre elles consiste à décentraliser le traitement des tâches de gestion, lorsque cela s avère judicieux. Notre réflexion s est concentrée plus particulièrement sur l ordonnancement dynamique des machines virtuelles, pour donner naissance à la proposition DVMS (Distributed Virtual Machine Scheduler). Nous avons mis en œuvre un prototype, que nous avons validé au travers de simulations (notamment via l outil SimGrid), et d expériences sur le banc de test Grid 5000. Nous avons pu constater que DVMS se montrait particulièrement réactif pour gérer des infrastructures virtualisées constituées de dizaines de milliers de machines virtuelles réparties sur des milliers de nœuds. Nous nous sommes ensuite penchés sur les perspectives d extension et d amélioration de DVMS. L objectif est de disposer à terme d un gestionnaire décentralisé complet, objectif qui devrait être atteint au travers de l initiative Discovery qui fait suite à ces travaux.The increasing need in computing power has been satisfied by federating more and more computers (called nodes) to build the so-called distributed infrastructures. Over the past few years, system virtualization has been introduced in these infrastructures (the software is decoupled from the hardware by packaging it in virtual machines), which has lead to the development of software managers in charge of operating these virtualized infrastructures. Most of these managers are highly centralized (management tasks are performed by a restricted set of dedicated nodes). As established, this restricts the scalability of managers, in other words their ability to be reactive to manage large-scale infrastructures, that are more and more common. During this Ph.D., we studied how to mitigate these concerns ; one solution is to decentralize the processing of management tasks, when appropriate. Our work focused in particular on the dynamic scheduling of virtual machines, resulting in the DVMS (Distributed Virtual Machine Scheduler) proposal. We implemented a prototype, that was validated by means of simulations (especially with the SimGrid tool) and with experiments on the Grid 5000 test bed. We observed that DVMS was very reactive to schedule tens of thousands of virtual machines distributed over thousands of nodes. We then took an interest in the perspectives to improve and extend DVMS. The final goal is to build a full decentralized manager. This goal should be reached by the Discovery initiative,that will leverage this work.NANTES-ENS Mines (441092314) / SudocSudocFranceF

Towards Modular Instrumentation of Interpreters in JavaScript

International audienceWith an initial motivation based on the security of web applications written in JavaScript, we consider the instrumentation of an interpreter for a dynamic analysis as a crosscutting concern. We define the instrumentation problem – an extension to the expression problem with a focus on modifying interpreters. We then illustrate how we can instrument an interpreter for a simple language using only the bare language features provided by JavaScript

Open Scope: A Pragmatic JavaScript Pattern for Modular Instrumentation

We report on our experience instrumenting Narcissus, a JavaScript interpreter written in JavaScript, to allow the dynamic deployment of dynamic program analyses. Instrumenting an interpreter is a cross-cutting change that can affect many parts of the interpreter source code. We propose a simple open scope pattern that minimizes the changes to the interpreter, while allowing us to implement program analyses in their own files, and to compose them dynamically. We apply our pattern to Narcissus using standard JavaScript features, and find that the gain in extensibility offsets a small loss in performance

Constructive Privacy for Shared Genetic Data

International audienceThe need for the sharing of genetic data, for instance, in genome-wide association studies is incessantly growing. In parallel, serious privacy concerns rise from a multi-party access to genetic information. Several techniques , such as encryption, have been proposed as solutions for the privacy-preserving sharing of genomes. However, existing programming means do not support guarantees for privacy properties and the performance optimization of genetic applications involving shared data. We propose two contributions in this context. First, we present new cloud-based architectures for cloud-based genetic applications that are motivated by the needs of geneticians. Second, we propose a model and implementation for the composition of watermarking with encryption, fragmentation, and client-side computations for the secure and privacy-preserving sharing of genetic data in the cloud

Aspectual Session Types

International audienceMultiparty session types allow the definition of distributed processes with strong communication safety properties. A global type is a choreographic specification of the interactions between peers, which is then projected locally in each peer. Well-typed processes behave accordingly to the global protocol specification. Multiparty session types are however monolithic entities that are not amenable to modular extensions. Also, session types impose conservative requirements to prevent any race condition, which prohibit the uni- form application of extensions at different points in a protocol. In this paper, we describe a means to support modular extensions with aspectual session types, a static pointcut/advice mechanism at the session type level. To support the modular definition of crosscut- ting concerns, we augment the expressivity of session types to al- low harmless race conditions. We formally prove that well-formed aspectual session types entail communication safety. As a result, aspectual session types make multiparty session types more flexible, modular, and extensible

A framework for the detection and resolution of aspect interactions

Aspect-Oriented Programming (AOP) promises separation of concerns at the implementation level. However, aspects are not always orthogonal and aspect interaction is an important problem. Currently there is almost no support for the detection and resolution of such interactions. The programmer is responsible for identifying interactions between conflicting aspects and implementing conflict resolution code. In this paper, we propose a solution to this problem based on a generic framework for AOP. The contributions are threefold: we present a formal and expressive crosscut language, two static conflict analyses and some linguistic support for conflict resolution