Github user NicoK commented on a diff in the pull request: https://github.com/apache/flink/pull/4533#discussion_r154697358 --- Diff: flink-runtime/src/main/java/org/apache/flink/runtime/io/network/partition/consumer/RemoteInputChannel.java --- @@ -378,6 +381,11 @@ public void notifyBufferDestroyed() { // Nothing to do actually. } + @VisibleForTesting + public void increaseCredit(int credit) { --- End diff -- or how about recycling a `Buffer` instance into the channel via `RemoteInputChannel#recycle()? That would also be part of the current interface and yield the same result but is a bit more hacky (but similar to calling `onSenderBacklog` with the advantage being closer to your `increaseCredit` method).
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