Package org.apache.storm.windowing
Class WaterMarkEventGenerator<T>
java.lang.Object
org.apache.storm.windowing.WaterMarkEventGenerator<T>
- All Implemented Interfaces:
Runnable
Tracks tuples across input streams and periodically emits watermark events. Watermark event timestamp is the minimum of the latest tuple
timestamps across all the input streams (minus the lag). Once a watermark event is emitted any tuple coming with an earlier timestamp can
be considered as late events.
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Constructor Summary
ConstructorDescriptionWaterMarkEventGenerator
(WindowManager<T> windowManager, int intervalMs, int eventTsLagMs, Set<GlobalStreamId> inputStreams) Creates a new WatermarkEventGenerator. -
Method Summary
Modifier and TypeMethodDescriptionvoid
run()
void
shutdown()
void
start()
boolean
track
(GlobalStreamId stream, long ts) Tracks the timestamp of the event in the stream, returns true if the event can be considered for processing or false if its a late event.
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Constructor Details
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WaterMarkEventGenerator
public WaterMarkEventGenerator(WindowManager<T> windowManager, int intervalMs, int eventTsLagMs, Set<GlobalStreamId> inputStreams) Creates a new WatermarkEventGenerator.- Parameters:
windowManager
- The window manager this generator will submit watermark events tointervalMs
- The generator will check if it should generate a watermark event with this intervaleventTsLagMs
- The max allowed lag behind the last watermark event before an event is considered lateinputStreams
- The input streams this generator is expected to handle
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Method Details