Github user HeartSaVioR commented on the issue:
https://github.com/apache/storm/pull/2829
If my understanding is right, there's pendingEmits (unbounded) which comes
into play when it can't push tuple immediately, so emit should not block,
nextTuple should not block as well. If emit can block in spout it could be
pretty much a big risk (ack/fail is not handled as well and tuples will fail
into timeout, and it may raise backpressure again).
@roshannaik Could you confirm?---
