Exploiting spatial parallelism in Ethernet-based cluster interconnects

In this work we examine the implications of building a single logical link out of multiple physical links. We use MultiEdge [12] to examine the throughput-CPU utilization tradeoffs and examine how overheads and performance scale with the number and speed of links. We use lowlevel instrumentation to understand associated overheads, we experiment with setups between 1 and 8 1-GBit/s links, and we contrast our results with a single 10-GBit/s link. We find that: (a) Our base protocol achieves up-to 65% of the nominal aggregate throughput. (b) Replacing the interrupts with polling significantly impacts only the multiple link configurations, reaching 80% of nominal throughput. (c) The impact of copying on CPU overhead is significant, and removing copying results in up-to 66% improvement in maximum throughput, reaching almost 100% of the nominal throughput. (d) Scheduling packets over heterogeneous links requires simple but dynamic scheduling to account for different link speeds and vary...

• Type: Conference
• Year: 2008
• Where: IPPS
• Authors: Stavros Passas, George Kotsis, Sven Karlsson, Angelos Bilas
• Keywords: Distributed And Parallel Computing, IPPS 2008, Nominal Throughput, Single Logical Link, Throughput-CPU Utilization Tradeoffs