{'fraction_non_alphanumeric': 0.02629016553067186, 'fraction_numerical': 0.006815968841285297, 'mean_word_length': 4.468085106382978, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
One Memory Access Sketch: A More Accurate and Faster Sketch for Per-Flow Measurement

Sketch is a probabilistic data structure widely used for per-flow measurement in the real network. The key metrics of sketches for per-flow measurement are their memory usage, accuracy, and speed. There are a variety of sketches, but they cannot achieve both high accuracy and high speed at the same time given a fixed memory size. To address this issue, we propose a new sketch, namely the OM (One Memory) sketch. It achieves much higher accuracy than the state-of-the- art, and achieves close to one memory access and one hash computation for each insertion or query. The key methodology of our OM sketch is to leverage word constraint and fingerprint techniques based on a hierarchical structure. Extensive experiments based on real IP traces show that the accuracy is improved up to 10.64 times while the speed is improved up to 2.50 times, compared with the well-known CM sketch. All the related source code has been released at GitHub.