HyGenICC: Hypervisor-based generic IP congestion control for virtualized data centers

In today's modern cloud supported applications, the traffic relies on both congestion-responsive transport protocols like TCP and congestion-oblivious transport like UDP including all their variations. As bandwidth is not totally virtualized in today's data centers, the diverse responses of these protocols to congestion lead to inefficiencies and service disruption to some applications. In this paper we present HyGenICC, a simple, distributed and practical congestion control mechanism that puts congestion control back where it belongs, in the network layer, albeit, without modifying the network layer behaviour. To this end IP ECN marking in the switches to indicate congestion, combined with additional packet processing in the hypervisor enable HyGenICC to partition bandwidth among competing virtual machines (VMs) in datacenters effectively. To enable easy deployment in existing data center, HyGenICC design is subjected to several constraints such as: i) freedom of changes to the guest VMs' congestion control mechanism, and ii) reliance only on switch capabilities that are already available in today's commodity switches. We evaluate HyGenICC via extensive simulation in the ns2 network simulator.