Datacenter configuration needs to be managed. A configuration engine (CE) manages configuration data of clusters and/or datacenters. The CE allows users to check out, edit, and check in configuration components. Versioned interfaces are placed between configuration components through data contracts. The CE supports the expression of constraints that ensure global consistency across configuration components and versions, isolates changes in the datacenter from structural changes in configuration components, and enables partial configuration branching to allow for active snapshots that enable configuration rollback. The CE ensures that types are consistent and constraints are satisfied at check-in time to eliminate unsound or inconsistent configuration in the first place. When the active configuration in the datacenter changes, multiple versions of configuration may be simultaneously deployed for a window of time. The managed set of configuration is permitted to have multiple active versions during these transitional windows to reflect the reality in the datacenter.