A Time Interval-Based Credit Reservation Approach for Prepaid Composite Services in Cloud Environments

A typical business model in cloud environments for service providers is the provision of composite services built from resources and services offered by other providers. Customers of these composite services can make an advance payment before consumption. In this scenario, accounting systems will supervise each service comprising given composite services individually. As the number of constituent services and requests submitted by customers increase dramatically, scalability issues arise. To tackle this problem, we present an approach that estimates the highest cost of a given composite service composed of multiple pre-paid services, and then calculates the duration of a time interval based on which accounting systems access and update target customers' account. It is intended to reduce overhead imposed by supervising services individually in real-time. Commercial agreements between involved business partners and potential economic compensations due to the violation of Service Level Agreement (SLA) are mirrored in the cost estimation.