Flightplan: Dataplane Disaggregation and Placement for P4 Programs.

Today's dataplane programming approach maps a whole P4 program to a single dataplane target, limiting a P4 program's performance and functionality to what a single target can offer. Disaggregating a single P4 program into subprograms that execute across different dataplanes can improve performance, utilization and cost. But doing this manually is tedious, error-prone and must be repeated as topologies or hardware resources change. We propose Flightplan: a target-agnostic, programming toolchain that helps with splitting a P4 program into a set of cooperating P4 programs and maps them to run as a distributed system formed of several, possibly heterogeneous, dataplanes. Flightplan can exploit features offered by different hardware targets and assists with configuring, testing, and handing-over between dataplanes executing the distributed dataplane program. We evaluate Flightplan on a suite of in-network functions and measure the effects of P4 program splitting in testbed experiments involving programmable switches, FPGAs, and x86 servers. We show that Flightplan can rapidly navigate a complex space of splits and placements to optimize bandwidth, energy consumption, device heterogeneity and latency while preserving the P4 program's behavior.