title: How to manage Kafka KStream to Kstream windowed join?
body: <p>Based on <a href="https://kafka.apache.org/documentation/streams#streams_dsl_joins" rel="noreferrer">apache Kafka docs</a> <code>KStream-to-KStream Joins are always windowed joins</code>, my question is how can I control the size of the window? Is it the same size for keeping the data on the topic? Or for example, we can keep data for 1 month but join the stream just for past week?</p>
  <p>Is there any good example to show a windowed KStream-to-kStream windowed join?</p>
  <p>In my case let's say I have 2 KStream, <code>kstream1</code> and <code>kstream2</code> I want to be able to join 10 days of <code>kstream1</code> to 30 days of <code>kstream2</code>.</p>