P4Rex: Accelerating regular expression matching with programmable switches

Regular expression matching is pivotal in numerous network applications. With the ever-increasing scale of data center traffic, deploying regular expression matching modules on traditional servers struggles to meet throughput demands. Emerging programmable switches have brought new prospects for high-speed pattern matching. However, deploying regular expression matching onto programmable switches presents the challenge of space explosion incurred by compiling regular expressions into a Deterministic Finite Automata (DFA). In this paper, we introduce P4Rex, a regular expression matching system designed for programmable switches. P4Rex synergistically leverages two following techniques: an efficient regular expression grouping algorithm that partitions regular expressions into different groups to reduce memory consumption, and DFA compression technology to achieve transition sharing. Experimental results demonstrate that P4Rex exhibits an average improvement of 17% and maximum improvement of 30% on memory consumption compared to prior regular expression grouping schemes and saves more than 10x memory consumption compared to deploying DFA directly on programmable switch.