RDMA over Converged Ethernet (RoCE) promises low latency and low CPU utilization over commodity networks, and is attractive for cloud infrastructure services. Current implementations require Priority Flow Control (PFC) that uses backpressure-based congestion control to provide lossless networking to RDMA. Unfortunately, PFC compromises network stability. As a result, RoCE's adoption has been slow and requires complex network management. Recent efforts, such as DCQCN, reduce the risk to the network, but do not comp…