When set, every lock() step on this controller is transparently delegated to the remote server identified by this ID (delegated mode), regardless of whether the pipeline DSL specifies a serverId parameter or not.

If the DSL also specifies a serverId that differs from this value, the forced server ID takes precedence and an INFO log message is written to the build log.

The value must match the Server ID of one of the configured remote servers listed below. Leave blank to disable delegated mode (default: peer mode only).

Example: set to prod-controller to route all locks to the remote server whose Server ID is prod-controller.