Hi all, Using
I am using a session window of 1 minute to detect and prevent duplicated events within the window using reduce() to preserve the first seen value and accumulate how often duplicates were seen, I'm then converting the windowed KTable into a stream to continue processing events. However, later in the stream, I've been hitting NPEs because after the window expiry, the stream is emitting a previously seen key with a null value when I'd assumed any values in the stream would be non-null. Is this an idiom expressing that the window for that key has expired and as such needs to be explicitly handled? I'm worried that my filtering those values from the ongoing stream is hiding a problem further upstream, but if it's working as designed, then sweet as. Kind regards, Liam Clarke
