Netshare and stochastic netshare

Abstract

Application performance in cloud data centers often depends crucially on network bandwidth, not just the aggregate data transmitted as in typical SLAs. We describe a mechanism for data center networks called NetShare that requires no hardware changes to routers but allows bandwidth to be allocated predictably across services based on weights. The weights are either specified by a manager, or automatically assigned at each switch port based on a virtual machine heuristic for isolation. Bandwidth unused by a service is shared proportionately by other services, providing weighted hierarchical max-min fair sharing. On a testbed of Fulcrum switches, we demonstrate that NetShare provides bandwidth isolation in various settings, including multipath networks.