Hi Max,
you can use keyed state on an operator with parallelism 1 if you assign a
default key with a KeySelector:
stream.keyBy(new NullByteKeySelector)
with NullByteKeySelector defined as
public class NullByteKeySelector<T> implements KeySelector<T, Byte> {
private static final long serialVersionUID = 614256539098549020L;
@Override
public Byte getKey(T value) throws Exception {
return 0;
}
}
With this trick, all records are assigned to the same key and you can use
keyed state and timers.
Best, Fabian
2018-02-13 9:59 GMT+01:00 m@xi <makisnt...@gmail.com>:
> Hello XingCan,
>
> Finally, I did it with union.
>
> Now inside the processElement() function of my CoProcessFunction I am
> setting a timer and periodically I want to print out some data through the
> onTimer() function.
>
> Below I attach the image stating the following: "Caused by:
> java.lang.UnsupportedOperationException: Setting timers is only supported
> on
> a keyed streams."
>
> <http://apache-flink-user-mailing-list-archive.2336050.
> n4.nabble.com/file/t1161/Screen_Shot_2018-02-13_at_16.png>
>
> My CoProcessFunction is an operator with parallelism=1 (I also use
> forceNonParallel()) to make sure about that. Thus, I am not using a Keyed
> State.
>
> Is the Keyed State the only way of using Timers?
>
> Furthermore, I must confess that the API is not so clear for the Managed
> Operator State, so I am currently NOT implementing any CheckpointedFunction
> etc etc.
>
> Is my application going to return the correct results, if I assume no
> failures etc etc.?
>
> Thanks in advance.
>
> Best,
> Max
>
>
>
> --
> Sent from: http://apache-flink-user-mailing-list-archive.2336050.
> n4.nabble.com/
>
