Optical interconnects are already the dominant technology in large-scale data center networks. However, the high optical loss of many optical components coupled with the low efficiency of laser sources result in high aggregate power requirements for the thousands of optical transceivers used by these networks. As optical interconnects stay always on even as traffic demands ebb and flow, most of this power is wasted. We present LC/DC, a data center network system architecture in which the operating system, the switch, and the optical components are co-designed to achieve energy proportionality. LC/DC capitalizes on the path divergence of data center networks to turn on and off redundant paths according to traffic demand, while maintaining full connectivity. Turning off redundant paths allows the optical transceivers and their electronic drivers to power down and save energy. Maintaining full connectivity hides the laser turn-on delay. At the node layer, intercepting send requests within the OS allows for the NIC's laser turn-on delay to be fully overlapped with TCP/IP packet processing, and thus egress links can remain powered off until needed with zero performance penalty. We demonstrate the feasibility of LC/DC by i) implementing the necessary modifications in the Linux kernel and device drivers, ii) implementing a 10Gbit/s FPGA switch, and iii) performing physical experiments with optical devices and circuit simulations. Our results on university data center traces and models of Facebook and Microsoft data center traffic show that LC/DC saves on average 60% of the optical transceivers power (68% max) at the cost of 6% higher packet delay.
翻译:光学互连是大型数据中心网络中的主要技术。然而,许多光学部件的高度光学损失,加上激光源的低效率,导致这些网络使用的数千台光学收发器的总电量需求很高。光学互连即使在交通需求起伏和流动时,这些电量大多被浪费了。我们介绍了数据中心网络系统结构,即操作系统、开关和光学组件共同设计以实现能源比例比例的数据中心网络结构。LC/DC利用数据中心网络的偏差,以便根据交通需求打开和关闭冗余路径,同时保持完全的连通性。关闭冗余路径使光学收发收发器及其电子驱动器能够下电和节省能源。保持完全连连,隐藏了激光开关的延迟。在节层,拦截内部服务器内部的发送请求,以便与IMC/IP包处理完全重叠。因此,在需要的零性能约束下,数据中心的电流路段路段路段路段路段路段路段路段路段路段路段路段的电路段可以继续断断。我们展示了LC/C/DC运行10GFDLFA系统的平均成本数据运行的升级。