I've ran into a bug where GetHTTP will stop working after the processor has been started and stopped a couple times. What I mean by "stop working" is that the processor will start the tasks, but no output is ever generated, no errors/warnings, and no FlowFiles show up in Provenance. The weird thing is that it always works the first time. Sometimes it breaks after one start/stop, sometimes it lasts two or three cycles. But the end state is always the same. The only way I've been able to get around this issue is by deleting and re-creating the processor, or by restarting NiFi completely.