[ https://issues.apache.org/jira/browse/FLINK-5285?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15732633#comment-15732633 ]
ASF GitHub Bot commented on FLINK-5285: --------------------------------------- Github user StephanEwen commented on a diff in the pull request: https://github.com/apache/flink/pull/2964#discussion_r91547796 --- Diff: flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/io/BarrierTracker.java --- @@ -225,17 +230,19 @@ private void processCheckpointAbortBarrier(CancelCheckpointMarker barrier, int c pendingCheckpoints.removeFirst(); } } - else { + else if (checkpointId > latestPendingCheckpointID) { notifyAbort(checkpointId); - // first barrier for this checkpoint - remember it as aborted - // since we polled away all entries with lower checkpoint IDs - // this entry will become the new first entry - if (pendingCheckpoints.size() < MAX_CHECKPOINTS_TO_TRACK) { - CheckpointBarrierCount abortedMarker = new CheckpointBarrierCount(checkpointId); - abortedMarker.markAborted(); - pendingCheckpoints.addFirst(abortedMarker); - } + latestPendingCheckpointID = checkpointId; + + CheckpointBarrierCount abortedMarker = new CheckpointBarrierCount(checkpointId); + abortedMarker.markAborted(); + pendingCheckpoints.addLast(abortedMarker); --- End diff -- Small comment here: I would - either keep the `addFirst()` statement here (we can be sure that is true, given that we pulled out all older checkpoints) - or add a sanity check that `pendingCheckpoints` is empty at that point. That way we explicitly guard the assumption that `pendingCheckpoints` contains entries on ordered sequence (which is currently only implicitly guarded by the `checkpointId > latestPendingCheckpointID` condition. > CancelCheckpointMarker flood when using at least once mode > ---------------------------------------------------------- > > Key: FLINK-5285 > URL: https://issues.apache.org/jira/browse/FLINK-5285 > Project: Flink > Issue Type: Bug > Components: State Backends, Checkpointing > Affects Versions: 1.2.0, 1.1.3 > Reporter: Till Rohrmann > Assignee: Till Rohrmann > Fix For: 1.2.0, 1.1.4 > > > When using at least once mode ({{BarrierTracker}}), then an interleaved > arrival of cancellation barriers at the {{BarrierTracker}} of two consecutive > checkpoints can trigger a flood of {{CancelCheckpointMarkers}}. > The following sequence is problematic: > {code} > Cancel(1, 0), > Cancel(2, 0), > Cancel(1, 1), > Cancel(2, 1), > Cancel(1, 2), > Cancel(2, 2) > {code} > with {{Cancel(checkpointId, channelId)}} -- This message was sent by Atlassian JIRA (v6.3.4#6332)