Hi,
I'm new to trident and I'm trying to solve the following use case. I've
read several times the documentation and I've been quite deep in the code
base but couldn't figure out how to do it...
My input tuples have the keys (user, some_int_1, some_int_2).
My output should be the sum of some_int_1 and the sum of some_int_2 (two
fields, not one) by user, ie. (user, total_some_int_1, total_some_int_2).
I've tried something like that:
myStream.groupBy(new Fields("user"))
.persistentAggregate(new MemoryMapState.Factory(),
new Fields("some_int_1", "some_int_2"),
new Sum(),
new Fields("total_some_int_1", "total_
some_int_2"))
but got
Exception in thread "main" java.lang.IllegalArgumentException: Combiner
aggs only take a single field as input. Got this instead: [total_some_int_1,
total_some_int_2]
what is the correct way of doing this ?
thanks
