Memory-efficient Sketch Acceleration for Handling Large Network Flows on FPGAs

Sketch-based algorithms for network traffic monitoring have drawn increasing interest in recent years due to their sub-linear memory efficiency and high accuracy. As the volume of network traffic grows, software-based sketch implementations cannot match the throughput of the incoming network flows. FPGA-based hardware sketch has shown better performance compared to software running on a CPU when handling these packets. Among the various sketch algorithms, Count-min sketch is one of the most popular and efficient. However, due to the limited amount of on-chip memory, the FPGA-based count-Min sketch accelerator suffers from performance drops as network traffic grows. In this work, we propose a hardware-friendly architecture with a variable width memory counter for count-min sketch. Our architecture provides a more compact design to store the sketch data structure effectively, allowing us to support larger hash tables and reduce overestimation errors. The design makes use of a P4-based programmable data plane and the AMD OpenNIC shell. The design is implemented and verified on the Open Cloud Testbed running on AMD Alveo U280s and can keep up with the 100 Gbit link speed.