Research And Implementation Of SaaS Oriented SLA Management Framework

To ensure the quality of web service, the tenants and web service providers sign anagreement called Service Level Agreement (SLA). This agreement defines some servicequality indicators, such as response time, number of active users, availability and reliability.As the rapid development of cloud computing platform, the number of web service keptincreasing, and the range also expanded, resulting in the massive growth of the Web services,which has brought great difficulties to the SLA management. At the same time, this broughtchallenges on SLA based web service composition and service resource optimization.Currently, there is not a unified SLA template for the parameter definitions and themeasurement units in SLAs for different web services, which makes the automate processingof the SLA content and SLA based dynamic service composition and optimization difficult.The human involvements increase the cost of service.In this thesis, under the service quality management environment, we research on how tobuild the ontology model for Service Level Agreement, how to realize the automation of thestages during the management of SLA based on the ontology model, and to optimize theservice resources based on SLA. And at last, we research about the whole series of problemsin SLA governance and optimization.The main research work is as follows: (1) By researching the current mainstream SLA realizations, the summarization of coreelements in the SLA is completed. And based on the concept of the domain ontology, adescription of the elements in SLA is proposed. An OWL-based scalable SLA model isestablished. Then the SLA ontology model based semantic matching degree and numericalmatching degree model of SLA parameters are proposed.(2) The method of semantic supported SLA lifecycle management is studied, whichincludes the automation of SLA matching and initialization, automatic monitoring of SLAexecution using the Semantic Web Rule Language (SWRL). Based on the model, a SLAbased web service composition method and a dynamic web service selection optimizationbased on Markov decision process are proposed.(3) An ontology based SLA lifecycle management platform is built. According to theSLA management method proposed earlier in this thesis, a prototype system is developed.This prototype system includes the SLA ontology building, parameter resolving, automaticnegotiation of SLA, automatic monitoring of SLA parameters and SLA based resourceoptimization.The validation of theoretical model together with prototype system shows that thisframework could guarantee the quick and effective management of SLA in cloud computingplatform.