  Many distributed applications implement complex data flows and need a
flexible mechanism for routing data between producers and consumers. Recent
advances in programmable network interface cards, or SmartNICs, represent an
opportunity to offload data-flow tasks into the network fabric, thereby freeing
the hosts to perform other work. System architects in this space face multiple
questions about the best way to leverage SmartNICs as processing elements in
data flows. In this paper, we advocate the use of Apache Arrow as a foundation
for implementing data-flow tasks on SmartNICs. We report on our experiences
adapting a partitioning algorithm for particle data to Apache Arrow and measure
the on-card processing performance for the BlueField-2 SmartNIC. Our
experiments confirm that the BlueField-2's (de)compression hardware can have a
significant impact on in-transit workflows where data must be unpacked,
processed, and repacked.
