thanks for the pointer!
2014-07-09 20:52 GMT+02:00 Danijel Schiavuzzi <dani...@schiavuzzi.com>: > Take a look at the custom CountSumSum CombinerAggregator here: > https://github.com/dschiavu/trident-mssql/blob/master/src/test/java/storm/trident/mssql/MssqlStateTopology.java > > Basically, you implement your own Aggregator which may output only one > Field, but you store a java.util.List into the field, so you may aggregate > multiple input fields and pack them into a List which is subsequently > dispatched into a State implementation's multiPut() or multiGet() method, > where you can then unpack the single values from the List and store them > separately into your persistent storage (for example, into separate columns > of an SQL table). > > The above example provides a working example for this. > > > On Wednesday, July 9, 2014, c_inconnu <c_incon...@yahoo.fr> 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 >> >> > > -- > Danijel Schiavuzzi > > E: dani...@schiavuzzi.com > W: www.schiavuzzi.com > T: +385989035562 > Skype: danijels7 >
