The definition of "stale configuration"

Cloudera Manager (CM) marks a service as stale whenever its configuration in the CM differs from what the running processes on the hosts are using. This can happen for the following reasons:

• A CDP control plane operation (for example, cross-realm trust setup or removal) updated the CM configuration on the cluster but did not restart the affected services.
• An administrator changed a configuration value in the CM without restarting the service.
• A related infrastructure operation, such as a database settings migration, rewrote the CM service configuration.

Stale configuration is not a failure. The cluster keeps running with the previous configuration until the service is restarted. Some changes (for example, a new trusted realm) only take effect after the service picks up the new configuration, so the restart is what actually activates the change.

The restart-runtime-services command instructs the CM to restart the services on the cluster and redeploy client configuration, which clears the stale state and applies the pending configuration.