Dynamic Service Reconfiguration Research Articles

A Dynamic Service Reconfiguration Method for Satellite–Terrestrial Integrated Networks

Satellite–terrestrial integrated networks (STINs) are regarded as a promising solution to meeting the demands of global high-speed seamless network access in the future. Software-defined networking and network function virtualization (SDN/NFV) are two complementary technologies that can be used to ensure that the heterogeneous resources in STINs can be easily managed and deployed. Considering the dual mobility of satellites and ubiquitous users, along with the dynamic requirements of user requests and network resource states, it is challenging to maintain service continuity and high QoE performance in STINs. Thus, we investigate the service migration and reconfiguration scheme, which are of great significance to the guarantee of continuous service provisioning. Specifically, this paper proposes a dynamic service reconfiguration method that can support flexible service configurations on integrated networks, including LEO satellites and ground nodes. We first model the migration cost as an extra delay incurred by service migration and reconfiguration and then formulate the selection processes of the location and migration paths of virtual network functions (VNFs) as an integer linear programming (ILP) optimization problem. Then, we propose a fuzzy logic and quantum genetic algorithm (FQGA) to obtain an approximate optimal solution that can accelerate the solving process efficiently with the benefits of the high-performance computing capacity of QGA. The simulation results validate the effectiveness and improved performance of the scheme proposed in this paper.

Dynamic reconfiguration of cloud application architectures

SummaryService‐based cloud applications are software systems that continuously evolve to satisfy new user requirements and technological changes. This kind of applications also require elasticity, scalability, and high availability, which means that deployment of new functionalities or architectural adaptations to fulfill service level agreements (SLAs) should be performed while the application is in execution. Dynamic architectural reconfiguration is essential to minimize system disruptions while new or modified services are being integrated into existing cloud applications. Thus, cloud applications should be developed following principles that support dynamic reconfiguration of services, and also tools to automate these reconfigurations at runtime are needed. This paper presents an extension of a model‐driven method for dynamic and incremental architecture reconfiguration of cloud services that allows developers to specify new services as software increments, and the tool to generate the implementation code for the services integration logic and the deployment and architectural reconfiguration scripts specific to the cloud environment in which the service will be deployed (e.g., Microsoft Azure). We also report the results of a quasi‐experiment that empirically validate our method. It was conducted to evaluate their perceived ease of use, perceived usefulness, and perceived intention to use. The results show that the participants perceive the method to be useful, and they also expressed their intention to use the method in the future. Although further experiments must be carried out to corroborate these results, the method has proven to be a promising architectural reconfiguration process for cloud applications in the context of agile and incremental development processes. Copyright © 2016 John Wiley & Sons, Ltd.

Dynamic Service Discovery, Composition and Reconfiguration in a Model Mapping Business Process to Web Services

In any organization where SOA has been implemented, all of the web services are registered in UDDI and users’ needs are served by using appropriate web services. So in this paper, we will try to discover a service from repository first that can provide the required output to the user. The process becomes difficult when a single service is not able to fulfill a user’s need and we need a combination of services to answer complex needs of users. In our paper, we will suggest a simpler approach for dynamic service composition using a graph based methodology. This will be a design time service composition. This approach uses the functional and non-functional parameters of the services to select the most suitable services for composition as per user’s need. This approach involves “service classification” on the basis of functional parameters, “service discovery” on the basis of user’s need and then “service composition” using the selected services on the basis of non-functional parameters like response time, cost, security and availability. Another challenge in SOA implementation is that, once the composition has performed, some services may become faulty at runtime and may stop the entire process of serving a user’s need. So, we will also describe a way of “dynamic service reconfiguration” in our approach that will enable us to identify and replace a faulty service that is violating the SLA or is not accessible anymore. This service reconfiguration is done without redoing or reconfiguring the entire composition. In the end, to simulate the proposed approach, we will represent a prototype application built on php 5.4 using My SQL database at backend.

Active Service for Mobile Middleware

This paper describes a dynamic service reconfiguration model where the proxy is composed of a chain of service objects called mobilets (pronounced as mo-be-lets), which can be actively deployed onto a network. This model offers flexibility because the chain of mobilets can be dynamically reconfigured to adapt to dynamic changes in the wireless environment, without interrupting service provision for other mobile nodes. We have realized the dynamic service reconfiguration model by crafting its design into a programmable infrastructure that forms the baseline architecture of the WebPADS (short for Web Proxy for Actively Deployable Services) system.

Toward an on demand service-oriented architecture

The success of an on demand e-business requires that business process, application, and information technology (IT) infrastructure integration merge into a comprehensive and cohesive architecture, where business process transformation drives service-oriented development and on demand enterprise computing. This enabling architecture is often described as a service-oriented architecture (SOA) and is a prerequisite accelerator for on demand solutions. The primary focus of SOA has been on dynamic reconfiguration of services from defined business processes, and on developing business services based on Web services and, more recently, grid services. Current descriptions of SOA are less focused on overall IT infrastructure enablement, both from a business policy perspective and within the context of service-oriented development. In this paper, we extend the current thinking on SOA to include a more comprehensive integration of business process transformation and the enabling technologies of service-oriented development and policy-based IT management. We call this extension on demand SOA. We develop these concepts by using an existing scenario: a financial services sector Life Change business process scenario, which involves distributed and disjoint transactions as well as stateless high-performance computing (HPC) applications.