Oops, yeah that field is now gone. Do you plan on using these values down
stream or do you just need to store the values somewhere? Here is how you
can change it but it doesn't give you a stream with the two counts.
GroupedStream g = myStream.groupBy(new Fields("user"));
g.persistentAggregate(new MemoryMapState.Factory(),
new Fields("some_int_1"),
new Sum(),
new Fields("total_some_int_1"));
g.persistentAggregate(new MemoryMapState.Factory(),
new Fields("some_int_2"),
new Sum(),
new Fields("total_some_int_2"));
On Wed, Jul 9, 2014 at 7:20 PM, c_inconnu <[email protected]> wrote:
> Thank you
>
> While asking this question, I have actually implemented a quick and dirty
> combinator that combine a pair, and that's working. But there is a lot of
> edge cases (I think) and so I'm not satisfied with it. Will need a lot more
> work.
>
> As for your first suggestion, this unfortunately does not work :
>
> Trying to select non-existent field: 'some_int_2' from stream containing
> fields fields: <[user, total_some_int_1]>
>
> What's the purpose of newValuesStream() then ?
>
>
> 2014-07-09 19:20 GMT+02:00 Sam Goodwin <[email protected]>:
>
>> This may work.
>>
>> myStream.groupBy(new Fields("user"))
>> .persistentAggregate(new MemoryMapState.Factory(),
>> new Fields("some_int_1"),
>> new Sum(),
>> new Fields("total_some_int_1")
>> .newValuesStream()
>> .persistentAggregate(new MemoryMapState.Factory(),
>> new Fields("some_int_2"),
>> new Sum(),
>> new Fields("total_some_int_2");
>>
>> You could also create your own Function to combine 1 and 2 into a single
>> object and implement your own CombinerAggregator for it. This is how you
>> could do it with only one aggregate step and it also lets your store the
>> values together.
>>
>>
>> On Wed, Jul 9, 2014 at 7:38 AM, c_inconnu <[email protected]> wrote:
>>
>> 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
>>>
>>>
>
