Workflow specification and scheduling with security constraints in hybrid clouds

Hybrid cloud management must deal with resources from both public and private clouds, as well as their interaction. When workflows are executed in a hybrid cloud, dependencies among their components bring new factors to be considered during specification, scheduling, and virtual machine provisioning. In this paper, we describe three components, namely workflow code, scheduler, and resource allocator, which enable the specification and execution of workflows in hybrid clouds in the context of the AltoStratus middleware. We present a case study that shows the interaction among these components, and their applicability in practice.