Github user zhijiangW commented on a diff in the pull request: https://github.com/apache/flink/pull/4559#discussion_r157709904 --- Diff: flink-runtime/src/main/java/org/apache/flink/runtime/io/network/partition/PipelinedSubpartition.java --- @@ -52,6 +54,10 @@ /** Flag indicating whether the subpartition has been released. */ private volatile boolean isReleased; + /** The number of non-event buffers currently in this subpartition */ + @GuardedBy("buffers") + private volatile int buffersInBacklog; --- End diff -- Yes, I totally agree with your point of current status of spillable/spilled subpartitions and subpartition views. And I also think that the `PipelinedSubpartition` is the most important path and the `SpillableSubpartition` should not be very sensitive. I think we already reach a consensus for the way of `SpillableSubpartition` and I will do for that later. :)
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