Github user zentol commented on a diff in the pull request:
https://github.com/apache/flink/pull/4665#discussion_r138723827
--- Diff:
flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/operators/windowing/WindowOperator.java
---
@@ -132,6 +133,13 @@
*/
protected final OutputTag<IN> lateDataOutputTag;
+ /**
+ * Metrics about the lost data due to arrive late.
+ * */
+ protected final String loseData = "lost_data";
+
+ protected Counter lostDataCount;
--- End diff --
the counter is registered already in the open method upon initialization, i
think we're good on that front.
However, i would suggest to change this line to `protected final Counter
lostDataCount = new SimpleCounter()`, and the line in open() to
`metrics.counter(lostData, this.lostDataCount);`
---
