1. A method for configuring processing engines to process event streams generated by sensors devices, the method comprising: receiving, at one or more computer systems, information identifying a set of one or more processing components, each processing component in the set of processing components having a set of inputs and a set of outputs; receiving, at the one or more computer systems, information defining a set of one or more states associated with a state machine, each state in the set of states identifying how event data in the events streams generated by the sensor devices that satisfies selection criteria is to be handled by one or more designated processing components in the set of processing components; receiving, at the one or more computer systems, information defining a set of entry points into the state machine, each entry point identifying how event data in the event streams generated by the sensors devices that satisfies selection criteria is to be handled by one or more designated processing components in the set of processing components; generating, with one or more processors associated with the one or more computer systems, a specification of the state machine according to a metadata-based language that configures a processing engine to process the event streams generated by the sensor devices according to the state machine based on the information identifying the set of one or more processing components, the information defining the set of one or more states associated with the state machine, and the information defining the set of entry points into the state machine; and storing, in a storage device associated with the one or more computer systems, the specification generated for the state machine.