<monospace>IDIO</monospace>: Orchestrating Inbound Network Data on Server Processors

Network bandwidth demand in datacenters is doubling every 12 to 15 months. In response to this demand, high-bandwidth network interface cards, each capable of transferring 100s of Gigabits of data per second, are making inroads into the servers of next-generation datacenters. Such unprecedented data delivery rates on server endpoints raise new challenges, as inbound network traffic placement decisions within the memory hierarchy have a direct impact on end-to-end performance. Modern server-class Intel processors leverage DDIO technology to steer all inbound network data into the last-level cache (LLC), regardless of the network traffic&#x2019;s nature. This static data placement policy is suboptimal, both from a performance and an energy efficiency standpoint. In this work, we design <monospace>IDIO</monospace>, a framework that&#x2014;unlike DDIO&#x2014;dynamically decides where to place inbound network traffic within a server&#x2019;s multi-level memory hierarchy. <monospace>IDIO</monospace> dynamically monitors system behavior and distinguishes between different traffic classes to determine and periodically re-evaluate the best placement location for each flow: LLC, mid-level (L2) cache or DRAM. Our results show that <monospace>IDIO</monospace> increases a server&#x2019;s maximum sustainable load by up to <inline-formula><tex-math notation="LaTeX">$\sim$</tex-math><alternatives> <mml:math> <mml:mo>&#x223C;</mml:mo> </mml:math> <inline-graphic xlink:href="alian-ieq1-3044923.gif"/></alternatives></inline-formula>33.3% across various network functions.