The complexity of large networks makes their management a daunting task. State-of-the-art network management tools use workflow systems for automation, but they do not adequately address the substantial challenges in operation reliability. This paper presents Occam, a programming system that simplifies the development of reliable network management tasks. We leverage the fact that most modern network management systems are backed with a source-of-truth database, and thus customize database techniques to the context of network management. Occam exposes an easy-to-use programming model for network operators to express the key management logic, while shielding them from reliability concerns, such as operational conflicts and task atomicity. Instead, the Occam runtime provides these reliability guardrails automatically. Our evaluation demonstrates Occam's effectiveness in simplifying management tasks, minimizing network vulnerable time and assisting with failure recovery.

SmartNICs are on the rise as a packet processing platform, with the trend towards a uniform P4 programming model. However, unleashing SmartNIC packet processing performance in P4 is a formidable task. Traditional SmartNIC optimizations rely on low-level program tuning, but P4 abstractions operate at one level above. At the same time, today's P4 optimizations primarily focus on resource packing rather than performance tuning. We develop Pipeleon, an automated performance optimization framework for P4 programmable SmartNICs. We introduce techniques that are tailored to the performance characteristics of SmartNICs, and further leverage dynamic workload patterns for profile-guided optimization. Pipeleon pinpoints program hotspots at the P4 level and computes runtime optimization plans to specialize the program layout based on the latest profile. We have prototyped Pipeleon and applied it to optimize two popular P4 SmartNICs---Nvidia BlueField2 and Netronome Agilio CX---as well as a software SmartNIC emulator extended based on BMv2. Our results show that Pipeleon significantly improves SmartNIC packet processing performance in realistic scenarios.

Recent advances in TCP congestion control (CC) have achieved tremendous success with deep reinforcement learning (RL) approaches, which use feedforward neural networks (NN) to learn complex environment conditions and make better decisions. However, such ``black-box'' policies lack interpretability and reliability, and often, they need to operate outside the traditional TCP datapath due to the use of complex NNs. This paper proposes a novel two-stage solution to achieve the best of both worlds: first to train a deep RL agent, then distill its (over-)parameterized NN policy into white-box, light-weight rules in the form of symbolic expressions that are much easier to understand and to implement in constrained environments. At the core of our proposal is a novel symbolic branching algorithm that enables the rule to be aware of the context in terms of various network conditions, eventually converting the NN policy into a symbolic tree. The distilled symbolic rules preserve and often improve performance over state-of-the-art NN policies while being faster and simpler than a standard neural network. We validate the performance of our distilled symbolic rules on both simulation and emulation environments. Our code is available at https://github.com/VITA-Group/SymbolicPCC.

Our community has made significant progress in developing programmable network infrastructure, starting from the control plane and expanding to the data plane. As a latest trend, network devices are becoming runtime programmable while serving live traffic. This allows for reprogramming of individual device programs at fine-grained timescales to add or remove network functions. Many applications and services, however, need control over a combination of devices, including end host stacks, NICs, and switches, to accomplish their goals. We lay out our vision for runtime programmable networks, building upon device-level features to provide live, network-wide, runtime reprogramming. A whole-stack approach is needed with new programming models, compiler support, and network management abstractions. We outline a research agenda as a call to arms to the community.

The gap between CPU and networking speeds has motivated the development of SmartNICs for NF (network functions) offloading. However, offloading performance is predicated upon intricate knowledge about SmartNIC hardware and careful hand-tuning of the ported programs. Today, developers cannot easily reason about the offloading performance or the effectiveness of different porting strategies without resorting to a trial-and-error approach.