Another reason sites have been hesitant to participate in meta scheduling projects in the past is the lack of accounting. Resources dedicated to the metascheduler and then not used were not accountable to anyone or anything. These compute cycles were lost and because these cycles could not be charged to any account, no one was motivated to improve the state of affairs and decrease waste. In the Silver system, all resources are accountable. If a Silver creates a reservation on a local system, it, or the user it represents, is charged for those resources even if the meta job never appropriately uses those resources.
Every cycle claimed by the meta scheduler is trackable and accountable.
Also, as metascheduling grows in use, Silver will support a mechanism to allow sites to always track a job back to its actual owner for both accounting and security reasons. Finally, using interfaces to services provided by systems such as PNNL's QBank , more advanced accounting tracking capabilities will be supported as economic resource models evolve. For security reasons, the metascheduler must be as limited in its scope of access and control as possible. However, even using this limited set of commands, the metascheduler is able to fully function. With trust established through a key exchange or other suitable mechanism, the local scheduler must accept jobs from the metascheduler or other trusted third party.