A feedback loop was detected on the data path: list of operators.
A loop in the SPL program graph can potentially cause deadlock or infinite recursion if the submission of a tuple causes a new tuple to be submitted. Feedback loops can be used only for controlling operators where the new tuple causes the state of the operator to change, but does not cause the submission of a new tuple.
A primitive operator that expects a feedback loop needs to mark the input port with the controlPort element if that input port does not cause tuples to be submitted. The issue might be alleviated by adding a config threadedPort clause to introduce a new thread of control.
