Hello Flink users, first time poster here. I'm using an interval join in my Flink project, however I haven't found where late records get logged in metrics. Window Joins have "numLateRecordsDropped" implemented <https://github.com/apache/flink/blob/master/flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/operators/windowing/WindowOperator.java#L141>, but is there an equivalent within an interval join?
My main use case is to track how often a record falls outside of the lower and upper bounds when trying to join two streams. Interval Join looks like it simply short circuits <https://github.com/apache/flink/blob/master/flink-streaming-java/src/main/java/org/apache/flink/streaming/api/operators/co/IntervalJoinOperator.java#L222>when there is a late record? Maybe I am not understanding what defines a late record in this situation. Is there a good way to monitor when an interval join fails to join two streams? Currently I'm looking at the delta between two operator metrics, but it hasn't looked that reliable so far. Thanks, Chris Gillespie
