Juan Manuel Murillo

Coordinated Roles: Promoting Re-usability of Coordinated Active Objects Using Event Notification Protocols

Nowadays, the need for developing more and more complex applications with distributed capabilities has promoted the development of coordination models. The goal of these models is to express the synchronized interaction among the different components of a distributed application. Whilst the Concurrent Object Oriented Programming (COOP) paradigm has revealed special adaptation to the modeling of distributed applications, the integration of this paradigm with current coordination models results in a reduction of the potential re-usability of classes that negates the capital benefit of object orientation. The main contributions of this paper are twofold. Firstly, the Event Notification Protocols, a mechanism that permits the transparent monitoring of active objects, are presented. Secondly, Coordinated Roles, a general-purpose coordination model based on the event notification protocols is proposed. Coordinated Roles is integrated with the COOP paradigm in such a way that the reduction of re-usability is avoided. In addition, it provides flexibility, composability, polymorphism, distribution, and dynamic change of coordination patterns.

An ADL dealing with aspects at software architecture stage

Managing complex software systems is one of the most important problems to be solved by software engineering. The software engineer needs to apply new techniques that allow for their adequate manipulation. Software architecture is becoming an important part of software design, helping the designer to handle the structure and the complexity of large systems, and AOSD is a paradigm proposed to manage this complexity by considering crosscutting concerns throughout the softwares life-cycle. The suitability of the existence of an Aspect-Oriented (AO) architectural design appears when AO concepts are extended to the whole life-cycle. In order to adequately specify the AO design, aspect-oriented architecture description languages are needed. The formal basis of these will allow architects to reason about the properties of the software architecture. In this paper, a new architecture description language -AspectLEDA - is formally described in order to adequately manipulate AO concepts at the software architecture stage. The AspectLEDA translation process is also described. A toolkit assists the architect during the process. Finally, a prototype of the system can be obtained, and the correctness of the architecture obtained can be checked.

Aspect modelling at architecture design

The increment of the complexity of systems requires new techniques that allow manipulating it adequately. Software architecture is becoming an important part of software design, which helps developers to handle the complexity of large systems. In addition, the management of the evolution as well as the maintenance of complex systems are two of most important problems to be solved by software engineering. Several solutions have been considered, one of them being the separation of concerns. These concepts have been extended along the life cycle and thus, Aspect Oriented Software Development (AOSD) arose. In this paper the architectural design phase and Aspect Oriented concepts are considered jointly. A proposal introducing aspects modelling in the architecture design phase is presented. The research is based on the combined use of a conventional architecture description language and an exogenous co-ordination model. When new requirements are going to be included in the system, the proposal provides the required steps to allow its evolution and maintenance by specifying an Aspect Oriented Architecture, which will permit us to change the system easily.

A service-oriented framework for developing cross cloud migratable software

Highlights? Migrating applications between clouds is costly as it often requires redevelopment. ? We propose a tool for developing applications independently of their targeted cloud. ? The framework allows to segment and deploy applications across more than one cloud. ? Development tools should be provided to increase the accessibility of the cloud. Whilst cloud computing has burst into the current scene as a technology that allows companies to access high computing rates at limited costs, cloud vendors have rushed to provide tools that allow developers to build software for their cloud platforms. The software developed with these tools is often tightly coupled to their services and restrictions. Consequently vendor lock in becomes a common problem which multiple cloud users have to tackle in order to exploit the full potential of cloud computing. A scenario where component-based applications are developed for being deployed across several clouds, and each component can independently be deployed in one cloud or another, remains fictitious due to the complexity and the cost of their development. This paper presents a cloud development framework for developing cloud agnostic applications that may be deployed indifferently across multiple cloud platforms. Information about cloud deployment and cloud integration is separated from the source code and managed by the framework. Interoperability between interdependent components deployed in different clouds is achieved by automatically generating services and service clients. This allows software developers to segment their applications into different modules that can easily be deployed and redistributed across heterogeneous cloud platforms.

An Aspect-Oriented Adaptation Framework for Dynamic Component Evolution

This paper briefly describes the design of a dynamic adaptation management framework which exploits the concepts provided by Aspect-Oriented Software Development (AOSD), in particular Aspect-Oriented Programming (AOP). The framework uses reflection and adaptation techniques in order to support COTS composition and evolution by tackling issues related to signature and protocol interoperability. This provides a basic infrastructure for a non-intrusive, semi-automatic approach for syntactical and behavioural adaptation.

People as a Service: A Mobile-centric Model for Providing Collective Sociological Profiles

Researchers from sociological disciplines could greatly benefit from collective information from the many people who use mobile devices to communicate via various social apps and services. However, processing that information is difficult because its scattered among numerous social platforms. Furthermore, users are becoming increasingly concerned about how and by whom their information is being accessed. A new mobile-centric computing model allows sociological profiles of people to be generated, kept, and securely provided to third parties as a service. With this model, device owners can be fully aware and in control of how their information is accessed, while still contributing to collective sociological information.

Run-Time Adaptability of Synchronization Policies in Concurrent Object Oriented Languages

Adaptability and composability have become two of the most important research areas in concurrent object-oriented systems in recent years. Nevertheless, at the present time, COOLs do not provide enough support for the development of true adaptable and composable software because either i) the different aspects that appear in these systems, synchronization and behavior, are mixed in the same component or, ii) if they are properly separated in different components, once these components are woven the resulting executable piece of software is too rigid to be adapted or reconfigured at run-time. Our contention is that this last feature is very important in critical control systems where, due to unexpected environment changes, urgent and not preestablished decisions must be taken at run-time. From security and economic point of views, it is not admissible to stop the application, adapt it to the new environment and re-run it. In this context, under project PRI97C161 of Junta de Extremadura, we have developed the Disguises Model, a model mainly thought for a clear separation of synchronization and behavioral aspects. A new language for the specification of the composition rules between the synchronization and behavioral aspects is provided, allowing synchronization policies to be added, replaced or reconfigured at run-time, which is the main contribution of the proposed model.

Towards a Subject-Oriented Model-Driven Framework

Abstract Model-Driven Architecture is an approach which tackles such problems as: the high availability that a software product requires to be ready for use, the high degree of evolution that a software system has nowadays, etc. However, in the development of large complex systems, the benefits of that approach have been diminished due to the size and complexity of models that describe these kinds of systems. At this point Aspect-Oriented Software Development (AOSD) appears to improve the understanding, reusability and adaptation of the software artefacts. Its mechanism is based on modularization of crosscutting concerns in well-identified isolated entities called aspects. For this reason we propose to use together AOSD and MDA in the hope of reducing the shortcomings of the latter. Thus, aspects like security, replication, real-time constraints, etc., will be modelled by specialist modellers independently throughout the MDA framework. Our proposal exploits a tool for checking the consistency between different models (aspects) at the same level of abstraction; supporting the traceability of UML elements, requirements, and concerns; and controlling the impact of changes throughout the MDA framework.

Developing migratable multicloud applications based on MDE and adaptation techniques

Developing software for the cloud usually implies using the tools and libraries supplied by cloud vendors for each of their platforms. This strongly couples the software to specific platforms and penalizes its migration or interoperability with external cloud services, in what is known as vendor lock-in. Under these circumstances multicloud applications become difficult to build and maintain since they require multidisciplinary teams with expertise on multiple platforms, and the redevelopment of some components if the cloud deployment scenario is altered. The MULTICLAPP framework described in this paper tackles these issues by presenting a three-stage development process that allows multicloud applications to be developed without being coupled to any concrete vendor. MDE and adaptation techniques are used throughout the software development stages in order to abstract the software from each vendors service specifications. As a result of this, multicloud applications or their subcomponents can be reassigned to different cloud platforms without having to undergo a partial or complete redevelopment process.

A UML Profile for Modeling Multicloud Applications

The benefits of counting with a high number of providers for developing cloud applications are overshadowed by the vendor lock-in issue, which makes it difficult for service-based applications to be migrated and replicated in new platforms. The MULTICLAPP framework tackles this issue by providing a three stage development process for building multicloud applications where developers do not require specific expertise on cloud technologies. The application modeling stage is described in this paper, where a UML profile is used for modeling applications in a platform independent manner. Multicloud applications are modeled as a composition of software artefacts, where each can be assigned to a different platform. This provides an intuitive way of modeling applications, and when integrated in the MULTICLAPP framework, makes it easier for them to be developed, maintained and redeployed in different platforms.