I am trying to process watermarks in a

BroadcastConnectedStream

. However, I am not able to find any direct way to handle watermark events, similar to what we have in

processWatermark1

in a

KeyedCoProcessOperator

.

In the context of the example given in “A Practical Guide to Broadcast State in Apache Flink”, I have a user actions stream and a pattern stream. The pattern stream is broadcast and connected with the user actions stream. The result is a

BroadcastConnectedStream

. I want to handle user action events and pattern evens in this stream. In addition, I want to use a

processWatermark

function to perform an action in response to watermark events.

The problem is that a

BroadcastConnectedStream

has only

process()

function, no

transform()

, that takes a

(Keyed)BroadcastProcessFunction

. A

BroadcastProcessFunction

allows only to process elements, it doesn’t provide the interface to process watermarks. In contrast, a

ConnectedStream

(without broadcast) provides a transform function, which takes in an operator that provides a way to process watermarks.