An SLA Evaluator for Multimedia Content Adaptation Services

摘要

Content adaptation is used to adapt multimedia content to a version required by users. In the service-oriented scheme, adaptation functions are provided as services by third-party service providers. Clients pay for the consumed services and thus demand service quality. Providers advertise their services; each with varied quality-of-services (QoS). Some of these QoS however, may not be deliverable accordingly during the actual service execution due to heavy load. Thus, the provider should able to determine a current deliverable QoS before the service level agreement (SLA) is settled with the requesters. In this paper, we propose a strategy for service providers to evaluate incoming requests and capable of offering the new QoS to the requests potentially being initially rejected. The proposed strategy takes into account the current server load and requests' priority. We analysed the performance of the proposed strategy in terms of SLA settlement under various conditions. The results indicate that the proposed strategy performs well.