An edge-queued datagram service for all datacenter traffic
Vladimir Olteanu, Haggai Eran, Dragos Dumitrescu, Adrian Popa, Cristi Baciu, Mark Silberstein, Georgios Nikolaidis, Mark Handley, Costin Raiciu
NSDI '22: 19th USENIX Symposium on Networked Systems Design and Implementation, 2022
Modern datacenters support a wide range of protocols and in-network switch enhancements aimed at improving performance. Unfortunately, most new and legacy protocols and enhancements often don’t coexist gracefully because they inevitably interact via queuing in the network.
In this paper we describe EQDS, a new datagram service for datacenters that moves almost all of the queuing out of the core network and into the sending host. This enables it to support multiple (conflicting) higher layer protocols, while only sending packets into the network when decided by a receiver-driven credit scheme. EQDS can speed-up legacy TCP and RDMA stacks and enable transport protocol evolution, while benefiting from future switch enhancements without needing to modify higher layer stacks. We show through simulation and multiple implementations that EQDS can reduce FCT of legacy TCP by 2x, improve the NVMeOF throughput by 30%, and safely run TCP alongside RDMA on the same network.