Github user aljoscha commented on a diff in the pull request:
https://github.com/apache/flink/pull/1764#discussion_r55019932
--- Diff:
flink-streaming-scala/src/main/scala/org/apache/flink/streaming/api/scala/DataStream.scala
---
@@ -750,6 +750,34 @@ class DataStream[T](stream: JavaStream[T]) {
}
/**
+ * Assigns timestamps to the elements in the data stream and
periodically creates
+ * watermarks to signal event time progress.
+ *
+ * This method is used for cases where the programmer wants the
Watermarks emitted in
+ * the stream to lag behind the maximum timestamp seen so far by a
fixed period of time.
+ *
+ * For more general cases, use the general methods
+ * [[assignTimestampsAndWatermarks(AssignerWithPeriodicWatermarks)]]
+ * and
[[assignTimestampsAndWatermarks(AssignerWithPunctuatedWatermarks)]].
+ *
+ * @param fixedWatermarkTrailingPeriod the fixed lag between the
currently emitted
+ * watermark and the maximum
timestamp seen so far.
+ * @param extractor the method to extracts the timestamp from a given
record.
+ */
+ @PublicEvolving
+ def
assignTimestampsWithAFixedPeriodTrailingWatermark(fixedWatermarkTrailingPeriod:
Long,
--- End diff --
Should we really add methods on DataStream for specific assigners? Seems a
bit too much and the name is terribly long. :sweat_smile:
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