Automated Pattern-Based Service Deployment in Programmable Networks

This paper presents a flexible service deployment architecture for the automated, on-demand deployment of distributed services in programmable networks. The novelty of our approach is (a) the customization of the deployment protocol by utilizing modular building blocks, namely navigation patterns, aggregation patterns, and capability functions, and (b) the definition of a corresponding service descriptor. A customizable deployment protocol has several important advantages: It supports a multitude of services, and it allows for an ad hoc optimization of the protocol according to the specific needs of a service and the current network conditions. Moreover, our architecture provides an environment for studying new patterns which aim at reducing deployment latency and bandwidth for certain services. We demonstrate how the developed architecture can be used to setup a virtual private network, and we present measurements conducted with our prototype in the PlanetLab test network. Furthermore, a comparison of a distributed pattern with a centralized pattern illustrates the performance trade-off for different deployment strategie

A middleware service for coordinated adaptation of communication services in groups of devices

Abstract—Recent research in pervasive computing has shown that context-awareness and dynamic adaptation are fundamental requirements of mobile distributed applications. However, most approaches that focus on context-aware dynamic adaptation use only the context information available at the mobile device to trigger a local adaptation. However, for distributed collaborative applications this is clearly insufficient, since a same adaptation has to be done, in synch, at all mobile devices of the group, and hence should also be based on a commonly agreed context. Therefore, for such kinds of applications one requires mechanisms and protocols to exchange the context information among the devices and to coordinate of the adaptation operations at a group of mobile device. In this paper we present a middleware service for coordinated adaptation of communication services in groups of devices. At each device this adaptation is achieved with minimal disruption for the application’s remote interactions. This middleware service is based on the notion of global context and a generic protocol for global context election and synchronization of the adaptation steps, which we called Moratus. Our middleware service was implemented using JGroups and evaluated for groups of up to 30 devices, showing acceptable latency for groups of such size. I

A policy-based management architecture for flexible service deployment in active networks

This paper describes a dynamic, scalable and extensible policy-based network management (PBNM) system that is fully integrated with a service provisioning architectures for active networks. The key result is network customisation according to the needs of the different service providers and its end users. Our component-based service provisioning architecture enables us to render service- and user-specific requirements, across single/multiple administrative domains, at deployment time and to dynamically map service components onto the network using the corresponding management policies. The architecture presented in this paper describes the approach undertaken by the IST-FAIN research project as well as the main issues that we encounter in developing and integrating the PBNM with the service provisioning mechanism

How To Touch a Running System

The increasing importance of distributed and decentralized software architectures entails more and more attention for adaptive software. Obtaining adaptiveness, however, is a difficult task as the software design needs to foresee and cope with a variety of situations. Using reconfiguration of components facilitates this task, as the adaptivity is conducted on an architecture level instead of directly in the code. This results in a separation of concerns; the appropriate reconfiguration can be devised on a coarse level, while the implementation of the components can remain largely unaware of reconfiguration scenarios. We study reconfiguration in component frameworks based on formal theory. We first discuss programming with components, exemplified with the development of the cmc model checker. This highly efficient model checker is made of C++ components and serves as an example for component-based software development practice in general, and also provides insights into the principles of adaptivity. However, the component model focuses on high performance and is not geared towards using the structuring principle of components for controlled reconfiguration. We thus complement this highly optimized model by a message passing-based component model which takes reconfigurability to be its central principle. Supporting reconfiguration in a framework is about alleviating the programmer from caring about the peculiarities as much as possible. We utilize the formal description of the component model to provide an algorithm for reconfiguration that retains as much flexibility as possible, while avoiding most problems that arise due to concurrency. This algorithm is embedded in a general four-stage adaptivity model inspired by physical control loops. The reconfiguration is devised to work with stateful components, retaining their data and unprocessed messages. Reconfiguration plans, which are provided with a formal semantics, form the input of the reconfiguration algorithm. We show that the algorithm achieves perceived atomicity of the reconfiguration process for an important class of plans, i.e., the whole process of reconfiguration is perceived as one atomic step, while minimizing the use of blocking of components. We illustrate the applicability of our approach to reconfiguration by providing several examples like fault-tolerance and automated resource control

Automated Pattern-Based Service Deployment in Programmable Networks

This paper presents a flexible service deployment architecture for the automated, ondemand deployment of distributed services in programmable networks. The novelty of our approach is (a) the customization of the deployment protocol by utilizing modular building blocks, namely navigation patterns, aggregation patterns, and capability functions, and (b) the definition of a corresponding service descriptor. A customizable deployment protocol has several important advantages: It supports a multitude of services, and it allows for an ad hoc optimization of the protocol according to the specific needs of a service and the current network conditions. Moreover, our architecture provides an environment for studying new patterns which aim at reducing deployment latency and bandwidth for certain services. We demonstrate how the developed architecture can be used to setup a virtual private network, and we present measurements conducted with our prototype in the PlanetLab test network. Furthermore, a comparison of a distributed pattern with a centralized pattern illustrates the performance trade-off for different deployment strategies. KEY WORDS: service deployment; service description; on-demand service deployment; resource discovery

NeCoMan: middleware for safe distributed service deployment in programmable networks

Recent evolution in computer networks clearly demonstrates a trend towards complex and dynamic networks. To fully exploit the potential of such heterogeneous and rapidly evolving networks, it is essential for the protocol stacks of the connected devices to adapt themselves at runtime as the environment changes in which they execute. This illustrates the need for employing programmable (i.e. adaptable) network nodes. In this paper, we concentrate on deploying point-to-point based distributed services in programmable protocol stacks. More in detail, we examine safe runtime adaptations of such services so as to preserve service consistency in programmable networks. This has resulted in the development of the NeCoMan (Network Consistency Management) middleware, a generic distributed coordination platform responsible for safe addition, replacement and removal of point-to-point services among programmable nodes. The novelty of this reflective middleware is in its ability to improve the effectiveness of the deployment process. This is achieved by customizing the deployment process depending on the properties of both the network service that will be deployed and the underlying execution environment.status: publishe