Extending On-chip Interconnects for rack-level remote resource access

Abstract

The need to perform data analytics on exploding data volumes coupled with the rapidly changing workloads in cloud computing places great pressure on data-center servers. To improve hardware resource utilization across servers within a rack, we propose Direct Extension of On-chip Interconnects (DEOI), a high-performance and efficient architecture for remote resource access among server nodes. DEOI extends an SoC server node's on-chip interconnect to access resources in adjacent nodes with no protocol changes, allowing remote memory and network resources to be used as if they were local. Our results on a four-node FPGA prototype show that the latency of user-level, cross-node, random reads to DEOI-connected remote memory is as low as 1.16µs, which beats current commercial technologies. We exploit DEOI remote access to improve performance of the Redis in-memory key-value framework by 47%. When using DEOI to access remote network resources, we observe an 8.4% average performance degradation and only a 2.52µs ping-pong latency disparity compared to using local assets. These results suggest that DEOI can be a promising mechanism for increasing both performance and efficiency in next-generation data-center servers.