SALMON - An Architecture to Define, Store, Monitoring and Billing ISLAs in a Server Farm

Salmon (Service Agreement Levels for Monitoring Océano coNtracts) defines an architecture and prototype implementation of a system to specify and maintain Infrastructure Service Level Agreements (ISLAs). A contract is used to establish an ISLA between a customer and a service provider. Each contract includes multiple sections, such as report definition, violation policy descriptions, penalties for disruption of service and charging. Salmon will evaluate that the service provider has a sufficient number of resources to support the defined service level. Salmon will monitor the enforcement of the contract and will trigger the policy engine whenever a violation occurs. Contract violations are expressed as policies, which include a violation scenario, start and stop time, the monitor and an action that must be fired in order to calculate the violation penalty. The action is a procedure to correct the problem, and/or apply a monetary penalty on the service provider. A charging engine is responsible for the billing calculations. We address the problem of ISLA definition by using customer feedback and providing a flexible way to define and monitor the quality of service.