Hi, I'm working on something that uses the Flink Window feature. I have written a custom Trigger to build the Window I need.
I am using the Window feature because I need state and I need to expire (and clean) this state after a timeout (I use the onEventTime to do that). Because I need the data streaming in real time (augmented with the mentioned state) I 'FIRE' after every event. Just before I 'PURGE' the window I need the fact of this purge (and some of the stats of this Window) as a separate event in a separate 'DataStream'. Now the interfaces of the various classes only support output as a single java type (very sane choice). So what I do right now is put my events on something 'external' (HBase/Kafka) and read it in via a different Source implementation. My question: Is there a better way to do this? Can I (for example) create a special 'Source' that I can pass as a parameter to my Trigger and then onEventTime just output a 'new event' ? What do you recommend? -- Best regards / Met vriendelijke groeten, Niels Basjes
