LUSketch: A Fast and Precise Sketch for top-k Finding in Data Streams

Finding top-k flows in data streams is a fundamental task in network management. As the line rates continue to increase in a network, it becomes increasingly challenging to find the top-k flows precisely and quickly in real time. Existing algorithms that can achieve high precision suffer from a slow speed. In this paper, we propose a novel sketch, LUSketch, which is much faster than existing algorithms. LUSketch adopts a new strategy called limited-and-imperative-update to significantly improve the insertion speed. The key idea is to significantly reduce the number of update operations by establishing a connection between the sketch and heap part when tracking the top-k flows. Our experiment results show that, while maintaining a high precision, LUSketch achieves an insertion speed approximately 2 to 5 times higher than that of the state-of-the-art.