Smoothie plans safe fast network updates using flexible models
Configuration Migration Planning through Decoupled Modeling and Searching
Networking and Internet Architecture
Summary
Making big changes to how a computer network is set up can be tricky and slow because the changes must be done in the right order to avoid breaking connections. The authors created a tool called Smoothie that helps plan these changes more quickly and safely. Smoothie can understand different goals, like finishing quickly or minimizing disruption, by separating how it checks safety from how it searches for the best change steps. It can find plans that do many updates at once or one by one, and it often finishes planning within an hour.
What this means in practice
- •For network operators: Generate safe, customized orders for updating network devices to minimize downtime and meet different operational goals.
- •For cloud infrastructure teams: Plan large-scale parallel updates to cloud network configurations efficiently without service interruptions.
Authors
Dan Wang, Peng Zhang, Ratul Mahajan
Abstract
Executing large network configuration changes, called migrations, is slow and error-prone today; operators must manually devise a safe order for updating devices that does not disrupt traffic and meets operational intents (e.g., low total time). We develop Smoothie, a versatile migration planning framework that, unlike existing tools, can support diverse operational intents. Inspired by automated planning, it achieves versatility by decoupling the encoding of network safety and intents from the search for a viable plan. Smoothie uses symbolic simulation for general and scalable safety encoding, after which it can use a range of planners, including existing off-the-shelf planners and a new one we developed for optimized parallel plans. We demonstrate Smoothie's versatility and benchmark its performance using diverse migration scenarios on many topologies. It finds both sequential plans and parallel plans, and the parallel ones compress up to thousands of configuration updates into no more than 3 steps. Its versatility does not come at the expense of performance: finishing most planning tasks in less than 1 hour.