Andreas Hanemann

PerfSONAR: a service oriented architecture for multi-domain network monitoring

In the area of network monitoring a lot of tools are already available to measure a variety of metrics. However, these tools are often limited to a single administrative domain so that no established methodology for the monitoring of network connections spanning over multiple domains currently exists. In addition, these tools only monitor the network from a technical point of view without providing meaningful network performance indicators for different user groups. These indicators should be derived from the measured basic metrics. In this paper a Service Oriented Architecture is presented which is able to perform multi-domain measurements without being limited to specific kinds of metrics. A Service Oriented Architecture has been chosen as it allows for increased flexibility and scalability in comparison to traditional software engineering techniques. The resulting measurement framework will be applied for measurements in the European Research Network (GEANT) and connected National Research and Education Networks in Europe as well as in the United States.

A framework for failure impact analysis and recovery with respect to service level agreements

In todays IT service market customers urge providers to grant guarantees for quality of service (QoS) which are laid down in service level agreements (SLAs). To satisfy customers and to avoid penalties, service providers have to ensure that the agreed SLAs are met. Therefore, it is necessary to be able to effectively deal with resource failures which could endanger the SLAs by affecting the provided services. The effort for recovering from failures should be selected corresponding to the expected SLA violation costs. In this paper we present a framework to automatically determine the impact of resource failures with respect to services and service level agreements. We achieve this by monitoring the service quality from inside and outside the service provider and also by incorporating information about the current and expected future service usage. The expected costs of the resource failures are assessed to select an appropriate recovery alternative. Besides this short term perspective the impact analysis can also be employed to identify critical resources and to improve the service provisioning.

Algorithm design and application of service-oriented event correlation

The timely and efficient management of faults that affect the quality of services delivered to customers is an important issue for service providers with respect to their business goals. It includes the diagnosis of service faults which deals with the localization of their root causes within subservices and resources being part of the service realization. In this paper our service-oriented event correlation approach, which uses event correlation techniques to automate the diagnosis on the service layer is detailed. Our algorithm for the hybrid rule-based/case-based correlation methodology that also includes recently proposed active probing techniques is presented as well as its prototypical implementation at the Leibniz Supercomputing Center. This implementation is not limited to a small test environment, but has been carried out for requirements of the environment of this large service provider.

Assured service quality by improved fault management

The paradigm shift from device-oriented to service-oriented management has also implications to the area of event correlation. Todays event correlation mainly addresses the correlation of events as reported from management tools. However, a correlation of user trouble reports concerning services should also be performed. This is necessary to improve the resolution time and to reduce the effort for keeping the service agreements. We refer to such a type of correlation as service-oriented event correlation. The necessity to use this kind of event correlation is motivated in the paper. To introduce service-oriented event correlation for an IT service provider, an appropriate modeling of the correlation workflow and of the information is necessary. Therefore, we examine the process management frameworks IT Infrastructure Library (ITIL) and enhanced Telecom Operations Map (eTOM) for their contribution to the workflow modeling in this area. The different kinds of dependencies that we find in our general scenario are then used to develop a workflow for the service-oriented event correlation. The MNM Service Model, which is a generic model for IT service management proposed by the Munich Network Management (MNM) Team, is used to derive an appropriate information modeling. An example scenario, the Web Hosting Service of the Leibniz Supercomputing Center (LRZ), is used to demonstrate the application of service-oriented event correlation.

A framework for service quality assurance using event correlation techniques

Due to the increasing use of service level agreements for the provisioning of IT services, providers have to ensure that the guarantees for the quality of their offered services, expressed by quality of service parameters, are met. These guarantees are endangered by resource malfunctions in the providers infrastructure or quality degradations of services which are supplied by subproviders. To optimize the resolution of customer reports about service quality degradations affecting the quality guarantees we propose to apply event correlation techniques. In this paper we present a framework for this new kind of event correlation which is called service-oriented event correlation. The framework bridges the gap between the management of the infrastructure and the offer of services for the customers with respect to the service fault diagnosis. The application of event correlation approaches in the framework is examined in detail.

Quality Assurance in perfSONAR Release Management

Software release management is closely related to the management of software quality since only software with assured quality should be provided to users. While established best practices exist for the development of software within an organization, new challenges arise with the introduction of service oriented architectures which make it possible to develop loosely-coupled systems potentially involving different organizations. For these systems it is not sufficient to test parts individually, but the collaboration issues need to be taken into account. In the perfSONAR project a set of loosely-coupled Web services has been developed to perform and manage measurements of network performance in research backbone networks. For the transition of the service development into the provisioning of permanently operated services, a release management process has been devised. It is presented in this paper highlighting the aspects being taken into account. These are also relevant for similar projects where service oriented architectures are deployed.

Service Provisioning: Challenges, Process Alignment and Tool Support

Publisher Summary The provisioning of services in the field of information and communication technology (ICT) such as network and application services presents many challenges to service providers. Regarding the level of service customization, services span a broad range: from widely deployed commodity services, such as broadband internet access or email services, with millions of equal service instances, to individual services, such as an enterprise extranet or an in-house service like the service architecture of a World Wide Web (WWW) search engine with a single highly customized service instance. The vision of a service provider and also a competitive advantage is the achievement of “flow-through provisioning,” which means that a customer reviews a set of services offered to him by a provider, selects an appropriate service, chooses among the available service quality options, then places an accordingly formed service order, and waits for its almost instantaneous fulfillment. The high number of equal and relatively simple orders of commodity services allows automation of many steps in the provisioning workflow. Management systems and scripts are set up for this purpose, but they need constant maintenance and orchestrated resources. In contrast, individual services are characterized by a complex set of specific customer requirements and negotiations between service provider and customer on financial and technical matters. Automation is therefore less applicable. In customized services, service providers combine features of individual and commodity services.