Data engineering·Time and correctness in streams
you want 'five errors in any sixty seconds', so every event is counted in twelve overlapping windows at once.
Sliding window
Also calledhopping window, overlapping window
Fixed-length windows that advance by less than their length, so they overlap and a record falls into several. It is what you use for rolling alerts and moving averages, where the question is about any period of length N rather than about clock-aligned buckets. The cost is multiplication: state and output volume scale with length divided by slide, so a one-hour window sliding every minute is sixty times the work of the tumbling version.