Details

    • Type: Sub-task
    • Status: Closed
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 1.2.0, 1.3.0
    • Component/s: Streaming
    • Labels:
      None

      Description

      Right now, when a Trigger returns TriggerResult.PURGE from any of the on*() methods the WindowOperator will clear all state of that window (window contents, merging window set) and call Trigger.clear() so that the Trigger can clean up its state/timers.

      This is problematic in some cases. For example, with merging windows (session windows) this means that a late-arriving element will not be put into the session that was previously built up but will be put into a completely new session that only contains this one element.

      The proposed new behaviour is this:

      • Only clean window contents on PURGE
      • Register cleanup timer for any window, don't delete this on PURGE
      • When the cleanup timer fires: clean window state, clean merging window set, call Trigger.clear() to allow it to clean state/timers

      Together with FLINK-4415 this would give the trigger the power to purge state and window contents separately.

        Attachments

          Activity

            People

            • Assignee:
              aljoscha Aljoscha Krettek
              Reporter:
              aljoscha Aljoscha Krettek
            • Votes:
              0 Vote for this issue
              Watchers:
              2 Start watching this issue

              Dates

              • Created:
                Updated:
                Resolved: