Life in the Fast Lane

This paper explores the question: what abstractions are needed to support a more general form of stateful processing in programmable forwarding planes? It argues that we should look for clues from the domain of stream processing. As a case study, it describes an implementation of the Linear Road benchmark for stream processing systems written in P4. The artifact of our implementation, which runs on a programmable ASIC, provides a version of the benchmark that far exceeds the throughput of any prior work. More importantly, the experience provides perspective on the challenges for implementing stateful abstractions in P4.