MonSLAR: a middleware for monitoring SLA for RESTFUL services in cloud computing

Measuring the quality of cloud computing provision from the client´s point of view is important in order to ensure that the service conforms to the level specified in the service level agreement (SLA). With a view to avoid SLA violation, the main parameters should be determined in the agreement and then used to evaluate the fulfillment of the SLA terms at the client´s side. Current studies in cloud monitoring only handle monitoring the provider resources with little or no consideration to the client´s side. This paper presents MonSLAR, a User-centric middleware for Monitoring SLA for Restful services in SaaS cloud computing environments. MonSLAR uses a distributed architecture that allows SLA parameters and the monitored data to be embedded in the requests and responses of the REST protocol.