esper grouping output multiple newEvents

Question

My epl is simple:

select symbol, sum(price) from MarketData(symbol!='').win:time(5.5 sec) group by symbol

The listener:

update(EventBean[] newEvents, EventBean[] oldEvents) {
    System.out.println(newEvents.length); //sometimes it's greater than 1
}

I think it's not possible that newEvents.length > 1 for my epl.

Can someone explain this for me? Thanks

score 0 · Answer 1 · answered Sep 25 '17 at 16:06

0

Correct that for that EPL that you posted there is always "newEvents.length=1", provided that the listener does not also receive other output and values are indeed immutable, of course.

answered Sep 25 '17 at 16:06

user650839

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I print the newEvents and find that when newEvents.length=n, eventBean.get("symbol") ouputs n different symbol. I dont know why it will trigger different symbols at a time(an event) – bylijinnan Sep 26 '17 at 07:58
Provide a simple test class – user650839 Sep 26 '17 at 11:45

esper grouping output multiple newEvents

1 Answers1