Catálogo de publicaciones - libros

This paper presents a middleware platform we designed in order to allow the deployment of component-based software applications on mobile devices (such as laptops or personal digital assistants) capable of ad hoc communication. This platform makes it possible to disseminate components based on peer-to-peer interactions between neighboring devices, without relying on any kind of infrastructure network. It implements a cooperative deployment scheme. Each device runs a deployment manager, which maintains a local component repository, and which strives to fill this repository with software components it is missing in order to satisfy the deployment requests expressed by the user. To achieve this goal the deployment manager continuously interacts in the background with peer managers located on neighboring devices, providing its neighbors with copies of software components it owns locally, while obtaining itself from these neighbors copies of the components it is looking for.

Recent studies have shown the potential of using component frameworks for building flexible adaptable applications for deployment in distributed environments. However this approach is hindered by the complexity of deploying component-based applications, which usually involve a great deal of configuration of both the application components and system services they depend on. In this paper we propose an infrastructure for automatic dynamic deployment of J2EE applications, that specifically addresses the problems of (1) inter-component connectivity specification and its effects on component configuration and deployment; and (2) application component dependencies on application server services, their configuration and deployment. The proposed infrastructure provides simple yet expressive abstractions for potential application adaptation through dynamic deployment and undeployment of components. We report on our experience with implementing the infrastructure as a part of the JBoss J2EE application server and testing it on several sample J2EE applications.

The deployment of component-based software applications usually relies on a centralized repository where the components are stored. This paper describes a peer-to-peer approach for components distribution. The software components are distributed among a set of nodes participating in the execution of services. When a node wants to install a component which is not present locally, this component is both searched and installed using a peer-to-peer network. The proposed architecture is an underlayer for OSGi application ( bundles ) deployment and execution management.

We describe a methodology for developing and deploying distributed Java applications using a reflective middleware system called RAFDA. We illustrate the methodology by describing how it has been used to develop a peer-to-peer infrastructure, and explain the benefits relative to other techniques. The strengths of the approach are that the application logic can be designed and implemented completely independently of distribution concerns, easing the development task, and that this gives great flexibility to alter distribution decisions late in the development cycle.

The Sun Java Runtime Environment (JRE) is used for developing applications which can be run in a cross-platform operating environment. The underlying Java Virtual Machine (JVM) facilitates the execution of Java applications, but it still requires manual application deployment. There are various approaches, such as the Java Network Launch Protocol (JNLP), which address dynamic application deployment, but are limited in scope. In this paper, we present a new approach towards self-managing application deployment in a cross-platform operating environment. It is based on the idea of dynamically deducing an appropriate deployment process without user intervention. We present a self-descriptive deployment unit called crosslet and introduce crossware archives (XAR) to package and distribute it. The Java realization of the approach is described and its application for nomadic desktop computing is illustrated.

This paper presents two contributions to the study of component deployment for distributed real-time and embedded (DRE) systems. First, it uses an inventory tracking systems (ITS) as a case study to elicit challenges involved in deploying DRE systems to account for their quality of service requirements. Second, it describes how we designed and implemented the Deployment And Configuration Engine (DAnCE), which is QoS-enabled middleware that addresses the challenges that arose in the context of our ITS case study. Our experience shows that DAnCE provides an effective platform for deploying DRE system components using a standard runtime environment and metadata.

In distributed and mobile environments, the connections among the hosts on which a software system is running are often unstable. As a result of connectivity losses, the overall availability of the system decreases. The distribution of software components onto hardware nodes (i.e., the system’s deployment architecture) may be ill-suited for the given target hardware en-vironment and may need to be altered to improve the software system’s avail-ability. The critical difficulty in achieving this task lies in the fact that deter-mining a software system’s deployment that will maximize its availability is an exponentially complex problem. In this paper, we present a fast approximative solution for this problem, and assess its performance. In addition to significantly improving availability, our solution, in general, also reduces the overall interaction latency in the system. We evaluate our solution on a large number of automatically generated application scenarios.

In distributed and mobile environments, the connections among the hosts on which a software system is running are often unstable. As a result of connectivity losses, the overall availability of the system decreases. The distribution of software components onto hardware nodes (i.e., the system’s deployment architecture) may be ill-suited for the given target hardware en-vironment and may need to be altered to improve the software system’s avail-ability. Determining a software system’s deployment that will maximize its availability is an exponentially complex problem. Although several polyno-mial-time approximative techniques have been developed recently, these techniques rely on the assumption that the system’s deployment architecture and its properties are accessible from a central location. For these reasons, the existing techniques are not applicable to an emerging class of decentralized systems marked by the limited system wide knowledge and lack of central-ized control. In this paper we present an approximative solution for the rede-ployment problem that is suitable for decentralized systems and assess its performance.

This paper addresses the distribution and the deployment of hierarchical components on heterogeneous dynamic networks. Such networks may include fixed and mobile resource-constrained devices and are characterized by the volatility of their hosts and connections, which may lead to their fragmentation. We propose a propagative, hierarchically-controlled deployment process for such networks and an ADL extension allowing the specification of this context-aware deployment.

Products within a product family are composed of different component configurations where components have different variable features and a large amount of dependency relationships with each other. The deployment of such products can be error prone and highly complex if the dependencies between components and the possible features a component can supply are not managed explicitly. This paper presents a method that uses the knowledge available about components to ensure correct, complete, and consistent deployment of configurations of interrelated components. The method provided allows the user to perform analysis on the deployment before the deployment is performed, thus allowing error prevention before making any changes to the system. The method and model are discussed and presented to provide an alternative to current component deployment techniques.