When does Trigger.clear() get called?

Posted by Andrew Danks on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/When-does-Trigger-clear-get-called-tp23809.html

Hello,

I see that the clear() function is implemented for various types of Triggers in the Flink API. For example:

https://github.com/apache/flink/blob/release-1.3/flink-streaming-java/src/main/java/org/apache/flink/streaming/api/windowing/triggers/ContinuousProcessingTimeTrigger.java#L87

I am working on a custom Trigger for my application and have implemented clear() in a similar way.

However, having put a breakpoint in this function it doesn’t seem to get called when I expect. The source code says that is called "when a window is purged”[1] but when my Trigger emits a PURGE this function never seems to get called. I am on Flink 1.3.

Hoping someone can shed more light on the purpose of clear() and how/when it gets called

Thanks!

Andrew

[1] https://github.com/apache/flink/blob/release-1.3/flink-streaming-java/src/main/java/org/apache/flink/streaming/api/windowing/triggers/Trigger.java#L111