You want to use an existing source but just change the watermark tracking? You can't do this in your pipeline right now, but you could probably easily wrap a source and proxy every method except getWatermark, though I have never tried.
The general feature that might address this is discussed a little on https://issues.apache.org/jira/browse/BEAM-644 There are also related ideas in the discussions about Splittable DoFn. Kenn On Thu, Apr 20, 2017 at 1:42 PM, Shen Li <[email protected]> wrote: > Hi, > > Can application developers provide classes/methods to specify how to > generate watermarks from sources, and how to aggregate watermarks from > multiple input PCollections? Say, emit at most 1 watermark per second, or > create watermarks that are 5 seconds older than the latest tuple's > timestamp? > > Thanks, > > Shen >
