The data center and its customers usually have service contracts which define the basic ties between the partners like partner locations and contacts, duration of the contract and cancellation policies as well as general pricing schemes and the like. This framework contract is amended by service level agreements (SLAs) that determine the nature of the service, performance terms of its delivery as well as metrics and measuring conditions, and penalties if the SLA are breached. Thus the customer generally expects from the data center to execute their jobs with at least the specification defined in the SLA and he or she is not made aware of the stress the workload execution puts on the energy providing system. Therefore the link between the energy consumption pattern of the data center and the options for energy supply are moved into the focus of All4Green.
The energy consumption in data centres depends on several parameters, and it can change according the time and other factors. Therefore, data centres should have a contract with energy providers in terms of energy consumption but also in terms of flexibility. At the other side of the eco-system, ICT end users must have a contract with the data center in terms of the SLA for the service provided, including the eco efficient components. To this end the project All4Green is developing specifically targeted GreenSLA that combine an increasing flexibility in terms of performance with eco-efficient goals and metrics.
Flexibility refers to peak and average load management, use of renewable energy sources, etc. As a result the data centre will get a rebate and can then further give the rebate to its own customers as a discount or others.
But this discount may also come at a price to its own customers to be flexible about the service to be received. Or, from the other side, it can offer its customers computing service based on green or clear energy, etc.
So, the Green-SLA concept has two perspectives:
a) An economic one.
b) A technical one, to analyze how to map and realize the contracts effectively.
So it includes adaptively, responsiveness, some level of optimization, and policies. These functionalities require some new proposals like an energy-aware layer to improve energy efficiency of existing IT solution deployment strategies and to manage overall power consumption, regarding to the eco chain, formed by a backbone for the energy provider, some local energy providers (reseller and producer), data centres (single or / and federated), and the customers of data centres.
One of the challenges for the All4Green GreenSLA will be not only to help steering the energy consumption in the data centre but to also do this in strong interconnection with the eco-efficient energy supply contracts developed between energy provider and data centre. The reason is that the main goal of the project is to decrease the environmental pressure of the total eco-system which implies that the contractual solutions must consistent with regards to this overall objective.