Synthesizing Cluster Management Code for Distributed Systems

Management planes for data-center systems are complicated to develop, test, maintain, and evolve. They routinely grapple with hard combinatorial optimization problems like load balancing, placement, scheduling, rolling upgrades and configuration management. To tackle these problems, developers are left with two bad choices: (i) develop ad-hoc mechanisms for systems to solve these optimization problems, or (ii) use specialized solvers that require steep engineering effort. We propose Weave, a tool that enables programmers to specify cluster management policies in a high-level declarative language, and compute policy-compliant configurations automatically and efficiently. Weave allows constraints and policies, the essence of a management plane, to be easily added, removed and modified over time, using a language familiar to developers (SQL). In this paper, we discuss our approach of management plane synthesis, its benefits, and present preliminary results from implementing a Kubernetes scheduler and a CorfuDB management plane using Weave.