Github user zhijiangW commented on the issue:
https://github.com/apache/flink/pull/4552
@pnowojski , this PR is ready for review.
It covers almost all the logics of credit-based on sender side.
In addition, I replace the current `PartitionRequestClientHandler` with
`CreditBasedClientHandler` and remove previous temporary codes for making this
feature work on both sides.
It leaves a small work to do in this PR related with
`SpilledSubpartitionView#nextBufferIsEvent` because the existing process in
spilled sub-partition can not get next buffer directly. But the current default
value for `nextBufferIsEvent`` will not affect the core process, only results
in wasting a unnecessary credit, then I will try to solve it in a lightweight
way later.
---
