NetShare: Virtualizing Data Center Networks across Services

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 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 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. (Joint work with Terry Lam, Siva Radhakrishnan, and Amin Vahdat)

Speaker Details

George Varghese worked at DEC for several years designing DECNET protocols and products (bridge architecture, Gigaswitch) before obtaining his Ph.D in 1992 from MIT. He worked from 1993-1999 at Washington University. He joined UCSD in 1999, where he currently is a professor of computer science. He won the ONR Young Investigator Award in 1996, and was elected to be a Fellow of the Association for Computing Machinery (ACM) in 2002. Together with colleagues, he has 16 patents awarded in the general field of Network Algorithmics. Several of the algorithms he has helped develop have found their way into commercial systems including Linux (timing wheels), the Cisco GSR (DRR), and Microsoft Windows (IP lookups). He also helped design the lookup engine for Procket’s 40 Gbps forwarding engine. He has written a book on building fast router and endnode implementations called “Network Algorithmics”. In May 2004, he co-founded NetSift Inc. which was acquired by Cisco Systems in 2005.

George Varghese
UC San Diego
    • Portrait of George Varghese

      George Varghese

      Principal Researcher