Ultra-Fast Bloom Filters using SIMD Techniques

The network link speed is growing at an ever-increasing rate, which requires all network functions on routers/switches to keep pace. Bloom filter is a widely-used membership check data structure in networking applications. Correspondingly, it also faces the urgent demand of improving the performance in membership check speed. To this end, this paper proposes a new Bloom filter variant called Ultra-Fast Bloom Filters (UFBF), by leveraging the Single Instruction Multiple Data (SIMD) techniques. We make three improvements for UFBF to accelerate the membership check speed. First, we develop a novel hash computation algorithm which can compute multiple hash functions in parallel with the use of SIMD instructions. Second, we elaborate a Bloom filter's bit-test process from sequential to parallel, enabling more bit-tests per unit time. Third, we improve the cache efficiency of membership check by encoding an element's information to a small block so that it can fit into a cache-line. We further generalize UFBF, called c-UFBF, to make UFBF supporting large number of hash functions. Both theoretical analysis and extensive evaluations show that the UFBF greatly outperforms the state-of-the-art Bloom filter variants on membership check speed.