17. The data processing apparatus of claim 16 , wherein the domain definition data structure comprises a plurality of stream processing component data structures in the description language, wherein each stream processing component data structure describes one or more input ports and one or more output ports.
17. The data processing apparatus of claim 16 , wherein the domain definition data structure comprises a plurality of stream processing component data structures in the description language, wherein each stream processing component data structure describes one or more input ports and one or more output ports. 19. The data processing apparatus of claim 17 , wherein each input port of each stream processing component is modeled using one or more preconditions on an action associated with the stream processing component.