A dynamic priority metascheduler for an SLA-based storage grid

Technological advancements in various fields of engineering generate large quantum of data, distributed geographically. Managing this data requires huge storage resources that can either be dedicated or can be shared. The dedicated storage being expensive and therefore, having shared storage is economical to provide the resources, as and when the demand is generated. In this paper, the authors propose a model of a special type of grid called storage grid that offers on demand storage services giving different types of storages to cater to different requirements of the users. It first prioritizes the requests of various users and then reserves the storage space and the type of storage for them in advance where an agreement is executed between the storage grid and the user commonly known as Service Level Agreement (SLA). The SLA postulates the terms and conditions governing provisioning of services on demand, pricing of services arising out of negotiations in the background of market value and a penal clause for levy of penalty that can be defrayed by allowing a discount in the price. The proposed storage grid consists of a metascheduler that manages the storage resources in terms of availability and allocation, taking care of the pricing and priority of the users hitherto embodied in the SLA. The performance evaluations were conducted through simulations for the storage requests acceptance and failures subject to reservation criterion.