Semantic-based policy engineering for autonomic systems

This paper presents some important directions in the use of ontology-based semantics in achieving the vision of Autonomic Communications. We examine the requirements of Autonomic Communication with a focus on the demanding needs of ubiquitous computing environments, with an emphasis on the requirements shared with Autonomic Computing. We observe that ontologies provide a strong mechanism for addressing the heterogeneity in user task requirements, managed resources, services and context. We then present two complimentary approaches that exploit ontology-based knowledge in support of autonomic communications: service-oriented models for policy engineering and dynamic semantic queries using content-based networks. The paper concludes with a discussion of the major research challenges such approaches raise

An architecture for autonomic web service process planning

Web service composition is a technology that has received considerable attention in the last number of years. Languages and tools to aid in the process of creating composite web services have been received specific attention. Web service composition is the process of linking single web services together in order to accomplish more complex tasks. One area of web service composition that has not received as much attention is the area of dynamic error handling and re-planning, enabling autonomic composition. Given a repository of service descriptions and a task to complete, it is possible for AI planners to automatically create a plan that will achieve this goal. If however a service in the plan is unavailable or erroneous the plan will fail. Motivated by this problem, this paper suggests autonomous re-planning as a means to overcome dynamic problems. Our solution involves automatically recovering from faults and creating a context-dependent alternate plan

08031 Abstracts Collection -- Software Engineering for Self-Adaptive Systems

From 13.01. to 18.01.2008, the Dagstuhl Seminar 08031 ``Software Engineering for Self-Adaptive Systems\u27\u27 was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available

Management of service composition based on self-controlled components

International audienceCloud computing and Future Internet promise a new ecosystem where everything is "as a service", reachable and connectable anywhere and anytime, everyone succeeding to get a service composition that meets his needs. But do we have the structure and the appropriate properties to design the service components and do we have the means to manage, at run-time, the personalised compositions corresponding to Service Level Agreement? In this article we introduce an entity of service composition called Self-Controlled Component (SCC), including, since the design step, functional and non-functional specifications. SCCs benefit both from the strong structure, explicit composition, and autonomic management of component-oriented programming, from the highly dynamic composition, and from the discovery capacities of service-oriented computing. Self-control mechanisms are then attached automatically to SCCs to enable autonomic application management during execution. The objective of this new concept is to provide strong Quality of Service (QoS) guarantees of composed applications. We illustrate the approach using an example called Springoo, to how in the context of a legacy application the contributions and benefits of our solution. For the management of the service composition we propose the concept of Virtual Private Service Network (VPSN) and Virtual Service Community (VSC) that allows us to model the personalised Service Level Agreement (SLA) where user requirements and provider offers converge on a QoS contract

Modeling Adaptation with Klaim

In recent years, it has been argued that systems and applications, in order to deal with their increasing complexity, should be able to adapt their behavior according to new requirements or environment conditions. In this paper, we present an investigation aiming at studying how coordination languages and formal methods can contribute to a better understanding, implementation and use of the mechanisms and techniques for adaptation currently proposed in the literature. Our study relies on the formal coordination language Klaim as a common framework for modeling some well-known adaptation techniques: the IBM MAPE-K loop, the Accord component-based framework for architectural adaptation, and the aspect- and context-oriented programming paradigms. We illustrate our approach through a simple example concerning a data repository equipped with an automated cache mechanism

QoS-based Self-Management for Business Processes

Business processes are commonly implemented as compositions of Web Services, using the Business Process Execution Language (BPEL) as an orchestration specification. Business processes do not only require an appropriate setup but also need to be monitored throughout their runtime, especially when Quality-of-service (QoS) constraints have to be met. Monitoring results may be used for the automated reconfiguration and optimization of business processes. We show how we achieve self-management based on QoS constraints within our system. The BPRules Language that we set up can be used to improve the QoS behavior of business processes by triggering appropriate management actions on the process. Also we propose a service selection strategy for the dynamic selection and replacement of services within business processes

Service Isolation vs. Consolidation: Implications for Iaas Cloud Application Deployment

Service isolation, achieved by deploying components of multi -tier applications using separate virtual machines (VMs), is a common \u27best\u27 practice. Various advantages cited include simpler deployment architectures, easier resource scalability for supporting dynamic application throughput requirements, and support for component-level fault tolerance . This paper presents results from an empirical study which investigates the performance implications of component placement for deployments of multi -tier applications to Infrastructure-as-a- Service (IaaS) clouds. Relationship s between performance and resource utilization (CPU, disk, network) are investigated to better understand the implications which result from how applications are deployed. All possible deployments for two variants of a multi -tier application were tested, one computationally bound by the model, the other bound by a geospatial database. The best performing deployments required as few as 2 VMs, half the number required for service isolation, demonstrating potential cost savings with service consolidation. Resource use (CPU time, disk I/O, and network I/O) varied based on component placement and VM memory allocation. Using separate VMs to host each application component resulted in performance overhead of ~1 -2%. Relationships between resource utilization an d performance were harnessed to build a multiple linear regression model to predict performance of component deployments. CPU time, disk sector reads, and disk sector writes are identified as the most powerful performance predictors for component deployments

Secure dynamic community establishment in coalitions

Accepted versio