Calibers: A bandwidth calendaring paradigm for science workflows

In this paper, we present the prototype architecture for Calibers using a central controller with distributed agents to dynamically pace flows at the ingress of the network to meet deadlines. Using Globus/Grid-FTP, we experimentally demonstrate that pacing can be used to meet data transfer deadlines which cannot be achieved using TCP. Finally, we present dynamic flow pacing algorithms that maximize acceptance ratio of flows for which deadlines can be met while maximizing network utilization. Our results show that simple heuristics, optimizing locally on the most bottlenecked link, can perform almost as well as heuristics that attempt to optimize globally.