Embodiments are directed to establishing a model for testing cloud components and to preventing cascading failures in cloud components. In one scenario, a computer system models identified cloud components (including cloud hardware components and/or cloud software components) as health entities. Each health entity is configured to provide state information about the cloud component. The computer system establishes declarative safety conditions which declaratively describe cloud computing conditions that are to be maintained at the identified cloud components. The computer system then tests against the declarative safety conditions to determine which cloud components are or are becoming problematic. Upon determining that an error has occurred, the computer system notifies users of the error and the component at which the error occurred. Guarded interfaces are established to ensure that actions taken to fix the error do not cause further failures.