[FLINK-12021] Let ResultConjunctFuture return future results in same order as futures

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.7.2, 1.8.0
• Fix Version/s: 1.7.3, 1.8.0
• Component/s: Runtime / Coordination
• Labels: pull-request-available
• Assignee: Till Rohrmann
• Reporter: Till Rohrmann
• Created: 26/Mar/19 10:46
• Updated: 05/Apr/19 11:57
• Resolved: 29/Mar/19 09:42

Description

The ResultConjunctFuture should return future results in the same order as the futures were specified. The advantage would be that we maintain the same output order as the input order if the input has been specified with a special ordering.

This should also fix a current performance regression where we don't maintain the topological ordering when deploying tasks. Due to this, we need to make an additional result partition lookup which adds additional latency. The problem has occurred due to FLINK-10431 which changes the interleaving how the slot futures are completed.

Issue Links

• links to: GitHub Pull Request #8060