Addressing Open Issues on Performance Evaluation in Cloud Computing
Cloud computing is an emerging paradigm that allows customers to easily obtain services according to a pay-per-use business model. The current Cloud providers include Quality of Service (QoS) guarantees in their Service Level Agreement (SLA) proposals . In general, they offer guarantees in terms of service availability and performance during a time period of months or a year. The provisioning contracts regulate the cost that customers have to pay for provided services and resources. Cloud service provider must pay a penalty if the customer's requirements are not satisfied. For example, the Cloud provider is liable to pay a penalty for service requests that are rejected due to unavailability of resources, or if the average service response time exceeds a fixed threshold. In order to support this model, ...