Any standardized components to generate watermarks based on
processing time in an event time stream when there is no data from a source?
The docs for event time  indicate that people are doing this, but the
only suggestion on Stack Overflow  is to make every window operator
in stream have a special processing time trigger, which seems clumsy
and error prone if you have many jobs and many windows.
I'm thinking there might be a watermark generator that can be plugged into the kafka consumer to make it generate processing time watermarks when there are no messages? Or maybe a standardized operator that can be inserted into the beginning of each stream, just after the source, to generate such idle-source processing time watermarks in event time streams?
1. "Note that sometimes when event time programs are processing live data in real-time, they will use some processing time operations in order to guarantee that they are progressing in a timely fashion."