Class SliceAssigners.SlicedSharedSliceAssigner

    • Constructor Detail

      • SlicedSharedSliceAssigner

        public SlicedSharedSliceAssigner​(int sliceEndIndex,
                                         SliceSharedAssigner innerAssigner)
    • Method Detail

      • nextTriggerWindow

        public Optional<Long> nextTriggerWindow​(long windowEnd,
                                                Supplier<Boolean> isWindowEmpty)
        Description copied from interface: SliceSharedAssigner
        Returns the optional end timestamp of next window which should be triggered. Empty if no following window to trigger for now.

        The purpose of this method is avoid register too many timers for each hopping and cumulative slice, e.g. HOP(1day, 10s) needs register 8640 timers for every slice. In order to improve this, we only register one timer for the next window. For hopping windows we don't register next window if current window is empty (i.e. no records in current window). That means we will have one more unnecessary window triggered for hopping windows if no elements arrives for a key for a long time. We will skip to emit window result for the triggered empty window, see SliceSharedWindowAggProcessor#fireWindow(Long).

        Specified by:
        nextTriggerWindow in interface SliceSharedAssigner
        Parameters:
        windowEnd - the current triggered window, identified by end timestamp
        isWindowEmpty - a supplier that can be invoked to get whether the triggered window is empty (i.e. no records in the window).
      • getLastWindowEnd

        public long getLastWindowEnd​(long sliceEnd)
        Description copied from interface: SliceAssigner
        Returns the last window which the slice belongs to. The window and slices are both identified by the end timestamp.
        Specified by:
        getLastWindowEnd in interface SliceAssigner