Hi, from your mail I'm gathering that you are in fact using an Evictor, is that correct? If not, then the window operator should not keep all the elements ever received for a window but only the aggregated result.
Side note, there seems to be a bug in EvictingWindowOperator that causes evicted elements to not actually be removed from the state. They are only filtered from the Iterable that is given to the WindowFunction. I opened a Jira issue for that: https://issues.apache.org/jira/browse/FLINK-4369 Cheers, Aljoscha On Wed, 10 Aug 2016 at 18:19 Shannon Carey <sca...@expedia.com> wrote: > One unfortunate aspect of using a fold() instead of a window is that the > fold function has no knowledge of the watermarks. As a result, it is > difficult to ensure that only items before the current watermark are > included in the aggregation, and that old items are evicted correctly. This > fact lends more support to the idea of using a custom operator (though that > is more complex) or adding support for this use case within Flink. > > -Shannon >
