Meta open-sources Rebalancer resource-allocation software

Meta released Rebalancer, its assignment-problem software, under the Apache 2.0 license after using it internally for roughly a decade. The system allocates resources such as tasks to servers, servers to services and traffic to data centers while enforcing capacity and reliability constraints. Users describe objects, destinations, constraints and objectives; Rebalancer converts that specification into an expression graph and applies either mixed-integer optimization or a parallel local-search method. Meta says it solves roughly 40 million assignment problems daily across more than 30 formulations. The local-search method favors scale and speed but does not guarantee the optimal result available from exact solvers.