Sharing the Data Center Network

While today’s data centers are multiplexed across many non-cooperating applications, they lack effective means to share their network. Relying on TCP’s congestion control, as we show from experiments in production data centers, opens up the network to denial of service attacks and performance interference. We present Seawall, a network bandwidth allocation scheme that divides network capacity based on an administrator-specified policy. Seawall computes and enforces allocations by tunneling traffic through congestion controlled, point to multipoint, edge to edge tunnels. The resulting allocations remain stable regardless of the number of flows, protocols, or destinations in the application’s traffic mix. Unlike alternate proposals, Seawall easily supports dynamic policy changes and scales to the number of applications and churn of today’s data centers. Through evaluation of a prototype, we show that Seawall adds little overhead and achieves strong performance isolation.