Memory-Efficient and Flexible Detection of Heavy Hitters in High-Speed Networks

Heavy-hitter detection is a fundamental task in network traffic measurement and security. Existing work faces the dilemma of suffering dynamic and imbalanced traffic characteristics or lowering the detection efficiency and flexibility. In this paper, we propose a flexible sketch called SwitchSketch that embraces dynamic and skewed traffic for efficient and accurate heavy-hitter detection. The key idea of SwitchSketch is allowing the sketch to dynamically switch among different modes and take full use of each bit of the memory. We present an encoding-based switching scheme together with a flexible bucket structure to jointly achieve this goal by using a combination of design features, including variable-length cells, shrunk counters, embedded metadata, and switchable modes. We further implement SwitchSketch on the NetFPGA-1G-CML board. Experimental results based on real Internet traces show that SwitchSketch achieves a high Fβ-Score of threshold-t detection (consistently higher than 0.938) and over 99% precision rate of top-k detection under a tight memory size (e.g., 100KB). Besides, it outperforms the state-of-the-art by reducing the ARE by 30.77%\sim99.96%. All related implementations are open-sourced.