The SLA Accounting component is responsible for computing the charges to be made to each consumer’s account according to a record of their usage for a specific service provider’s resources or services. The usage information should be provided by the Runtime Monitoring component. Moreover, the SLA Accounting Component may impose additional charges or discount to a user account as a penalty when notified by the Runtime Monitoring component of a violation from the customer’s or the Service Provider’s side respectively.
The SLA Accounting component must be able to receive and treat the notifications sent by the SLA Evaluation component. To this end, it should present a Web Service capable of receiving WS-Notifications. Such a Design Pattern is presented in Design Pattern for a GT4 Service receiving WS-notifications whitepaper.
Within a grid framework, once an SLA contract is agreed and contains monetary information describing usage (and possibly penalty) fees, there arises a need to justify the bill produced by the provider. On the basis of the SLA Accounting design pattern, the Accounting component receives usage information from the SLA Monitoring component. The usage information consists of aggregated measurements of the usage of the various resources created by combining monitoring data provided by the resources or the services. The SLA Accounting also receives a notification each time an SLA violation occurs and imposes penalties or discounts to the customer’s account based on the nature of the SLA-Violation and the agreed-upon penalty terms. The SLA Accounting Pattern enhances grid functionality by enabling the resource and service provider to charge consumers for usage of his services based on a predefined agreement between the two (SLA). It is a step towards making a grid application more commercial and business oriented.