Department of Computer Science & Engineering

Data centers lower costs by sharing the physical infrastructure among multiple services. However, the data center network should also ideally provide bandwidth guarantees to each service in a tunable manner while maintaining high utilization. We describe {\em NetShare}, a new statistical multiplexing mechanism for Data Center networks that does this without requiring changes to existing routers. NetShare allows the bisection bandwidth of the network to be allocated across services based on simple weights specified by a manager. Bandwidth unused by a service is shared proportionately by other services. More precisely, NetShare provides weighted hierarchical max-min fair sharing, a generalization of hierarchical fair queuing of individual {\em links}. We present three mechanisms to implement NetShare including one that leverages TCP flows and requires no changes to routers or servers. We show experiments using multiple Hadoop instances and a network of Fulcrum switches and show that the instances can interfere without NetShare and yet complete faster with NetShare when compared to the alternative of static reservation.

Pre-2018 CSE ID: CS2010-0957