I am writing a beam streaming pipeline, with 1 min Fixed Window.

I am reading data from PubSub, and using PubSub msg’s Timestamp:

beam.WindowInto(window.FixedWindows(60)))

As, PubSub msg already have Timestamp information, I am not giving Timestamp info explicitly.

Now, my question is:

1. Suppose I start my beam pipeline at “2019-03-27T09:50:00.000Z” and I start publishing to PubSub Topic at 2019-03-27T09:50:20.000Z, from which time the pipeline will start counting 1min? What will be window start and end time.

2. Second question, What If published msgs are out of order. I mean, suppose I published one msg at *2019-03-27T09:50:10.000Z *and another at 2019-03-27T09:50:40.000Z, but 2019-03-27T09:50:40.000Z arrives first and consumed by beam. So ,in this case, what will be start time of Window.

Thanks for the help in advance.

I have created streaming pipeline, and want to know, about window start time. Which time it consider as start of window.