Hi Walid, Granted it’s a little hard to understand without a picture, but the sentence is correct. Consider this: While a tuple is being processed by one of the parallelized bolts, it remains un-acked. So if there are ‘N’ parallel bolt instances, and you want them to all stay busy, then the system must allow at least ‘N’ unacked tuples to be in existence without complaining. Actually you should allow ‘N + a few’, so that you have a bit of queue to truly keep them busy. If you only allow ‘Q’ unacked tuples, where Q < N, then only Q parallel bolt instances can ever be busy at once; the Q+1’th un-acked tuple coming into the topology causes the limit to be exceeded.
Hope this helps, --Matt From: Walid Aljoby <[email protected]> Reply-To: "[email protected]" <[email protected]>, Walid Aljoby <[email protected]> Date: Friday, November 25, 2016 at 7:04 AM To: User <[email protected]> Subject: Number of unacked tuples Hi Everyone, Could anyone please explain this sentence by an example? I got confused with word "lower", I think it should be "higher". If the number of possible unacked tuples is lower than the total parallelism you’ve set for your topology, then it could be a bottleneck. Thank you, -- Regards WA
