A Reconfigurable Fabric for Accelerating Large-Scale Datacenter Services

Andrew Putnam, Adrian Caulfield, Eric Chung, Derek Chiou, Kypros Constantinides, John Demme, Hadi Esmaeilzadeh, Jeremy Fowers, Jan Gray, Michael Haselman, Scott Hauck, Stephen Heil, Amir Hormati, Joo-Young Kim, Sitaram Lanka, Eric Peterson, Aaron Smith, Jason Thong, Phillip Yi Xiao, Doug Burger, Jim Larus, Gopi Prashanth Gopal, Simon Pope

Proceeding of the 41st Annual International Symposium on Computer Architecuture (ISCA) |

Published by IEEE Press

Selected as an IEEE Micro TopPick

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Datacenter workloads demand high computational capabilities, flexibility, power efficiency, and low cost. It is challenging to improve all of these factors simultaneously. To advance datacenter capabilities beyond what commodity server designs can provide, we have designed and built a composable, reconfigurable fabric to accelerate portions of large-scale software services. Each instantiation of the fabric consists of a 6×8 2-D torus of high-end Stratix V FPGAs embedded into a half-rack of 48 machines. One FPGA is placed into each server, accessible through PCIe, and wired directly to other FPGAs with pairs of 10 Gb SAS cables. In this paper, we describe a medium-scale deployment of this fabric on a bed of 1,632 servers, and measure its efficacy in accelerating the Bing web search engine. We describe the requirements and architecture of the system, detail the critical engineering challenges and solutions needed to make the system robust in the presence of failures, and measure the performance, power, and resilience of the system when ranking candidate documents. Under high load, the large-scale reconfigurable fabric improves the ranking throughput of each server by a factor of 95% for a fixed latency distribution—or, while maintaining equivalent throughput, reduces the tail latency by 29%.

Ushering in the Era of Programmable Hardware

Larry Larsen speaks with Doug Burger about the findings of a Microsoft Research and Bing research project that equipped servers with reconfigurable hardware, in the form of field-programmable gate arrays (FPGAs), to accelerate datacenter services. Based on the success of the pilot, Bing will roll out FPGA-enhanced servers in one datacenter to process customer searches starting in early 2015.