OSGi Technology Research Articles

Goal-driven adaptive monitoring of SOA systems

The advent of the Service Oriented Architecture (SOA) enabled implementation of IT systems of increasing complexity, rendering effective monitoring a nontrivial task. The inherent scale and dynamism of such systems does not allow for simultaneous monitoring of all system elements without introducing noticeable overhead. Therefore, an important challenge arises in the field of SOA monitoring. There is a need for a solution which enables on-demand adjustment of the monitoring process in accordance with the demands of system administrators and the changing conditions of the execution environment. The paper addresses the identified need by proposing the concept of goal-driven adaptive monitoring, capable of performing dynamic management of the monitoring process. The proposed concept is used for designing the Dynamic Adaptive Monitoring Framework, referred to as DAMON, which can be installed in an existing SOA environment to provide it with adaptive monitoring features. For the purpose of evaluation, a prototype of the DAMON framework was implemented on the basis of the OSGi technology. The evaluation, presented in the paper, not only verified the functional aspects of DAMON, but it also proved that the framework can decrease the monitoring overhead in large-scale dynamic systems.

Model-driven Development and Validation of Multi-agent Systems in JIAC V with the Agent World Editor

In this work we describe the Agent World Editor, a graphical editor that supports the development and validation of multi-agent systems in JIAC V. For the development of this editor, which complies with the OSGi technology, a model-driven approach was used. Concepts that support the developer to design multi-agent systems in JIAC V have been developed as well. Developers do not need to configure their systems by hand, but can model them in a graphical manner. Errors are detected at design time, and the adaptive user interface offers additional guidance in the development process.

A distributed open source web-application for spatial multi-criteria evaluation for decision support systems infrastructure

Spatial data availability on internet or intranet rapidly increases. Laymen use this data through applications such as Google Maps, Google Earth and Virtual Earth. Relatively new standards allow interoperable use for publication, sharing and calculation of spatial data. We discuss the opportunities that new spatial and multi-criteria decision analysis web service technologies and standards offer in combination with technology to distribute computing and analysis. We report of the architecture and the first prototype of the open source Distributed Spatial Multi-Criteria Evaluation (D-SMCE) web application. It is extensible by using OSGi technology for modularity and different web-services from spatial domains, such as OGC web mapping, web feature and web processing services, and non-spatial domains, such as Decision Deck. Distributed SMCE is a framework and an application. The theoretical context shows how spatial planning and decision support systems can be understood to evolve, to relate practice of distributed evaluation with standards of D-SMCE.

Cloud-Based Collaborative Decision Making

The complexity of many decision problems of today’s globalized world requires new innovative solutions that are built upon proven decision support technology and also recent advancements in the area of information and communication technology (ICT) such as Cloud Computing and Mobile Communication. A combination of the cost-effective Cloud Computing approach with extended group decision support system technology bears several interesting unprecedented opportunities for the development of such solutions. These opportunities include ubiquitous accessibility to decision support software and, thus, the possibility to flexibly involve remote experts in group decision processes, guided access to background information, and facilitation support to direct group decision processes. The architects of such future solutions are challenged by numerous requirements that need to be considered and reflected in an integrated architectural approach. This article presents a thorough analysis of major design considerations for software solutions for collaborative decision making from a broad range of perspectives especially including the business process management perspective and the Cloud Computing perspective. The proposed architectural approach of the GRUPO-MOD system demonstrates how one can address the requirements in one integrated system architecture that supports different deployment options of Cloud Computing. A refinement of the high-level system architecture into a corresponding implementation architecture that builds on widely adopted standards such as OSGi and industry proven technology such as the Eclipse platform is also given in the article.

A survey on approaches for addressing dependability attributes in the OSGi service platform

The OSGi service platform is being used in software industry as the de facto middleware for developing and deploying modular Java applications, using SOA principles in centralized solutions. OSGi provides a dynamic platform where components and services can be deployed and undeployed at runtime, attracting the attention of both commercial and research projects. Although the platform is used in fields with different purposes (e.g. experimentally used in healthcare, commercially used in application servers) but where dependability should be a pre-requisite for applications, it is a fact that the OSGi technology does not provide a dependable platform for executing applications with such needs. Different research efforts try to address dependability attributes (availability, integrity, maintainability, reliability, safety, and confidentiality) in the OSGi service platform, but not necessarily all of these attributes are completely covered or explicitly addressed in the textual references. We provide a brief survey on recent research efforts that try to improve dependability in the OSGi service platform. We analyze and identify which attributes are addressed on each approach, and provide a discussion on the employed techniques, similarities and results achieved on such approaches. Al-though this survey remains limited to one technology (OSGi), the problematic as well as all the employed techniques in the analyzed efforts are pertinent to other service and component-based systems.

분산되어 있는 OSGi 프레임워크에서 효과적인 서비스 공유 방안

홈 네트워크 분야에서 주로 적용되었던 OSGi 기술은 현재 다양한 도메인의 이질적인 장치에 탑재되고 있다. 분산되어 있는 OSGi 프레임워크 환경에서 효과적인 서비스를 제공하기 위해서는 프레임워크들간의 상호작용이 필수적이다. 하지만 현재까지 공개된 OSGi 스펙에서는 원격 OSGi 프레임워크에 등록된 서비스를 공유할 수 있는 방안을 제공하지 않고 있다. 이와 같은 문제점을 해결하기 위하여 기존의 분산 미들웨어기술인 JXTA 또는 Web Services를 활용하는 기술들이 연구되었으나, 이러한 기술들은 컴퓨팅 자원을 많이 소모하고 또한 부가적인 서비스 변환과정이 필요하다는 문제점이 있다. R-OSGi는 OSGi 기술만을 사용하여 원격 서비스를 공유할 수 있는 방안을 제공하지만, 중앙집중적인 구조를 가짐으로써 병목현상이나 SPOF (Single Point Of failure)가 발생할 수 있다. 본 논문에서는 P2P 기반의 효과적인 서비스 공유 방안인RSP (Remote Service Provider)를 제안한다. RSP는 OSGi 자체 기술만을 사용하므로 서비스를 공유하기 위하여 추가적으로 다른 소프트웨어를 설치하거나, 그 소프트웨어를 사용하기 위한 변환과정이 필요 없다. 또한 P2P 방식의 서비스 발견 메커니즘을 사용하여 병목현상을 해결하고 확장성을 높일 수 있다. 그리고 RSP는 원격 서비스에 대한 투명성을 제공하고, 원격 서비스의 상태 변화를 즉각 통보하여 원격 서비스의 신뢰성을 보장하는 특징을 가진다. OSGi technology has applied to Home Network, but now it is loaded into even heterogeneous devices in various domains. Therefore, it is necessary to cooperate with each other framework for offering effective services in distributed OSGi frameworks. However until now, OSGi specification doesn't provide any methodthat can share the services registered on remote OSGi frameworks. In order to solve this problem, there have been several researches that used existing distributed middleware technologies such as JXTA and Web Services. However these technologies have some weakness, that is, they consume lots of computing resources and need additional process to transform the services. A middleware called R-OSGi uses only OSGi technology for sharing remote OSGi services, but R-OSGi may have a communication bottleneck and SPOF (Single Point of Failure) problem, because it has a central service registry. In this paper we present RSP (Remote Service Provider), which is a P2P-based effective service sharing scheme on distributed OSGi framework. RSP doesn't need to install additional software nor have the additional transformation process of the service representation, because it uses only OSGi technology. In addition it doesn't have any bottleneck problem and improves scalability by providing the service discovery mechanism using P2P. RSP can also access remote services transparently and it can guarantee reliability by sending an immediate notice about changes of the remote services.

Enriching OSGi Service Composition with Web Services

This letter describes combining OSGi and Web Services in service composition. According to our approach, a composite service is described in WS-BPEL. Each component service in the description may be resolved to either an OSGi service or Web Service at runtime. The proposal can overcome current limitations with OSGi technology in terms of its geographical coverage and candidate service population available for service composition.

Component-oriented programming

Preface. 1. Introduction. 1.1 What is COP? 1.2 Why is COP important? 1.3 What is a component? 1.4 Hardware components and software components. 1.5 From OOP to COP. 1.6 Component-based software engineering. 1.7 Summary. 1.8 Self-review questions. 1.9 Exercises. 2. A Theory of Components. 2.1 Principles of COP. 2.2 Infrastructures of COP. 2.3 Component models. 2.4 Connection models. 2.5 Deployment models. 2.6 Unifying component technologies. 2.7 Summary. 2.8 Self-review questions. 2.9 Exercises. 3. COP with JavaBeans. 3.1 Overview of JavaBeans technology. 3.2 The component model of JavaBeans. 3.3 The connection model of JavaBeans. 3.4 The deployment model of JavaBeans. 3.5 Examples and lab practice. 3.6 Summary. 3.7 Self-review questions. 3.8 Exercises. 4. Enterprise JavaBeans Components. 4.1 The EJB a rchitecture. 4.2 The component model of EJB. 4.3 The connection model of EJB. 4.4 The deployment model of EJB. 4.5 Examples and lab practice. 4.6 Summary. 4.7 Self-review questions. 4.8 Exercises. 4.9 Programming exercises. 5. CORBA Components. 5.1 The COBRA component infrastructure. 5.2 The CORBA component model (CCM). 5.3 The connection model of CORBA and CCM. 5.4 The deployment model of CORBA and CCM. 5.5 Examples and lab practice. 5.6 Summary. 5.7 Self-review questions. 5.8 Exercises. 5.9 Programming exercises. 6. .NET Components. 6.1 The .NET framework. 6.2 The component model of .NET. 6.3 The connection model of .NET. 6.4 .NET component deployments. 6.5 Visual Studio .NET. 6.6 Examples and lab practice. 6.7 Summary. 6.8 Self-review questions. 6.9 Exercises. 6.10 Programming exercises. 7. COP with OSGi Components. 7.1 Overview of OSGi technology. 7.2 The component model of OSGi. 7.3 The connection model of OSGi. 7.4 The deployment model of OSGi. 7.5 Examples and lab practice. 7.6 Summary. 7.7 Self-review questions. 7.8 Exercises. 8. Web Services Components. 8.1 The Web Services framework. 8.2 The component model of Web Services. 8.3 The connection model of Web Services. 8.4 Web Services component deployment. 8.5 Examples and lab practice. 8.6 Summary. 8.7 Self-review questions. 8.8 Exercises. 8.9 Programming exercises. Appendix.

Enabling smart spaces with OSGi

Today's pervasive computing spaces are developed primarily with proprietary technology and seem to lack a long-term vision of evolution and interoperation. The future pervasive computing environment will comprise a wide variety of devices and services from different manufacturers and developers. We must therefore achieve platform and vendor independence as well as architecture openness before pervasive computing spaces become common places. The Open Services Gateway Initiative attempts to meet these requirements by providing a managed, extensible framework to connect various devices in a local network such as in a home, office, or automobile. By defining a standard execution environment and service interfaces, OSGi promotes the dynamic discovery and collaboration of devices and services from different sources. Moreover, the framework is designed to ensure smooth space evolution over time and to support connectivity to the outside world, allowing remote control, diagnosis, and management. We present the OSGi technology and examine several OSGi development toolkits and products. We also share our experience in using OSGi to build an open, assistive environment that supports independent living for elders.