Under streaming analytics context, a session window function is usually used to group events that arrive around similar times and to filter out periods of time where there is no events.
Events can belong to only one session window. Session window function usually takes at least two parameters:
- Window timeout - A session window starts when the first event occurs and if new events occur within the timeout (compared with last ingested event), it will be included in the window otherwise the window will be closed at the timeout.
- Max window duration - If the events keep appearing, the window will close at the max window duration and a new window will start.