Service-level management of adaptive distributed network applications

The paper is on generic service-level management tools that enable the reconfiguration of a distributed network application whenever there are resource-level changes or failures in the underlying network sub-systems. A network service is provided to client applications through a protocol module, with the latter exercising network infrastructure resources in a manner to meet the client requirements. Client requests for a network service instantiate the underlying protocol module with parameters specified at the service interface level, along with a prescription of critical properties to be enforced therein. At run-time, a management module may automatically monitor the service compliance to client-prescribed requirements, and notify the client whenever a service quality degradation is detected. The paper proposes a 'function'-based model of service provisioning to realize our management approach. In this model, a service prescription conforms to generic interface templates based on an enumeration of the service attributes visible to clients, and how these attributes logically relate to one another in composing a client-level quality expectation. Our management model is independent of the specifics of problem-domain, which simplifies the development of distributed adaptive applications through a 'software reuse' of the management module. The paper presents the case study of an application: CDN, to demonstrate the usefulness of our model.