Energy-Efficient Data Transfers in Radio Astronomy with Software UDP RDMA

摘要

Modern radio astronomy relies on very large amounts of data that need to betransferred between various parts of astronomical instruments, over distancesthat are often in the range of tens or hundreds of kilometres. The SquareKilometre Array (SKA) will be the world's largest radio telescope, data ratesbetween its components will exceed Terabits per second. This will impose a hugechallenge on its data transport system, especially with regard to powerconsumption. High-speed data transfers using modern off-the-shelf hardware mayimpose a significant load on the receiving system with respect to CPU and DRAMusage. The SKA has a strict energy budget which demands a new, custom-designeddata transport solution. In this paper we present SoftiWARP UDP, an unreliabledatagram-based Remote Direct Memory Access (RDMA) protocol, which cansignificantly increase the energy-efficiency of high-speed data transfers forradio astronomy. We have implemented a fully functional software prototype ofsuch a protocol, supporting RDMA Read and Write operations and zero-copycapabilities. We present measurements of power consumption and achievedbandwidth and investigate the behaviour of all examined protocols whensubjected to packet loss.