If I do a fold on a KeyedStream, I aggregate events for such-and-such key. My question is, what happens with the aggregate (and its key) when events for this key stop coming? My keys are browser session keys, and are virtually limitless.
Ideally, I'd like to send some sort of purge event on keys a couple of days later, where I empty the aggregate in the fold. That still leaves the key though, where does that go? Any answers highly appreciated... Greetings Bart