Hi, using .keyBy(0) on a Scala DataStream[Tuple2] where Tuple2 is a Scala Tuple should work. Look, for example, at the SocketTextStreamWordCount example in Flink.
Cheers, Aljoscha > On 13 Jan 2016, at 18:25, Tzu-Li (Gordon) Tai <tzuli...@gmail.com> wrote: > > Hi Saiph, > > In Flink, the key for keyBy() can be provided in different ways: > https://ci.apache.org/projects/flink/flink-docs-master/apis/programming_guide.html#specifying-keys > (the doc is for DataSet API, but specifying keys is basically the same for > DataStream and DataSet). > > As described in the documentation, calls like keyBy(0) are meant for Tuples, > so it only works for DataStream[Tuple]. Other key definition types like > keyBy(new KeySelector() {...}) can basically take any DataStream of > arbitrary data type. Flink finds out whether or not there is a conflict > between the type of the data in the DataStream and the way the key is > defined at runtime. > > Hope this helps! > > Cheers, > Gordon > > > > > > -- > View this message in context: > http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/Flink-DataStream-and-KeyBy-tp4271p4272.html > Sent from the Apache Flink User Mailing List archive. mailing list archive at > Nabble.com.
