Suppose I trigger a Combine per-element (in a high-volume stream) and use a ParDo as a sink.
I assume there is no guarantee about the order that my ParDo will see these triggers, especially as it processes in parallel, anyway. That said, my sink writes to a db or cache and I would not like the cache to ever regress its value to something "before" what it has already written. Is the best way to solve this problem to always write the event-time in the cache and do a compare-and-swap only updating the sink if the triggered value in-hand is later than the target value? Or is there a better way to guarantee that my ParDo sink will process elements in-order? (Eg, if I can give up per-event/real-time, then a delay-based trigger would probably be sufficient I imagine.) Thanks for advice!
