NetCL: A Unified Programming Framework for In-Network Computing

The emergence of programmable data planes (PDPs) has paved the way for in-network computing (INC), a paradigm wherein networking devices actively participate in distributed computations. However, PDPs are still a niche technology, mostly available to network operators, and rely on packet-processing DSLs like P4. This necessitates great networking expertise from INC programmers to articulate computational tasks in networking terms and reason about their code. To lift this barrier to INC we propose a unified compute interface for the data plane. We introduce $\mathrm{C} / \mathrm{C}++$ extensions that allow INC to be expressed as kernel functions processing in-flight messages, and APIs for establishing INC-aware communication. We develop a compiler that translates kernels into P4, and thin runtimes that handle the required network plumbing, shielding INC programmers from low-level networking details. We evaluate our system using common INC applications from the literature.