1. A method for processing a stream of tuples, the method comprising: receiving a stream of tuples to be processed by a plurality of processing elements operating on one or more computer processors, each processing element having one or more stream operators, one or more of the stream operators including code configured to output tuples to one or more other stream operators; generating a window over one or more stream operators, the window being defined by a set of windowing conditions, the set of windowing conditions including a breakpoint threshold; determining a tuple flow count for the window, the tuple flow count corresponding to the breakpoint threshold; determining that a breakpoint condition has occurred by comparing the tuple flow count to the breakpoint threshold; and implementing, in response to determining that the breakpoint condition has occurred, a tuple flow change.