Github user aljoscha commented on a diff in the pull request:
https://github.com/apache/flink/pull/5481#discussion_r172135390
--- Diff: docs/dev/stream/operators/process_function.md ---
@@ -242,4 +242,17 @@ class CountWithTimeoutFunction extends
ProcessFunction[(String, String), (String
the current processing time as event-time timestamp. This behavior is very
subtle and might not be noticed by users. Well, it's
harmful because processing-time timestamps are indeterministic and not
aligned with watermarks. Besides, user-implemented logic
depends on this wrong timestamp highly likely is unintendedly faulty. So
we've decided to fix it. Upon upgrading to 1.4.0, Flink jobs
-that are using this incorrect event-time timestamp will fail, and users
should adapt their jobs to the correct logic.
\ No newline at end of file
+that are using this incorrect event-time timestamp will fail, and users
should adapt their jobs to the correct logic.
+
+## The KeyedProcessFunction
+
+`KeyedProcessFunction`, as an extension of `ProcessFunction`, gives access
to the key of timers in its `onTimer(...)`
+method.
+
+{% highlight java %}
--- End diff --
Maybe also add Scala example code.
---
