Re: counting elements in datastream

[Sameer W]

Use Count windows and keep emitting results say every 1000 elements and do
a sum. Or do without windows something like this which has the disadvantage
that it emits a new updated result for each new element (not a good thing
if your volume is high)-

https://github.com/sameeraxiomine/flinkinaction/blob/master/flinkinactionjava/src/main/java/com/manning/fia/c02/SimpleStreamingWordCount.java

Or use tumbling time windows on processing time -
 
https://github.com/sameeraxiomine/flinkinaction/blob/master/flinkinactionjava/src/main/java/com/manning/fia/c04/TimeWindowExample.java
.
Advantage over count windows is that you get a count every few (configured
seconds) which you can then add up on your client side.

Since you do not need a keyBy operation you would do this directly on the
DataStream instance without doing a keyBy but that way you get multiple
counts per partition of the stream which you will need to add up.





On Thu, Aug 18, 2016 at 5:54 AM, subash basnet  wrote:

> Hello all,
>
> If anyone had idea, what could be the probable way to count the elements
> of a current instance of the datastream. Is it possible?
>
> DataStream> pointsWithGridCoordinates;
>
>
>
> Regards,
> Subash Basnet
>

counting elements in datastream

[subash basnet]

Hello all,

If anyone had idea, what could be the probable way to count the elements of
a current instance of the datastream. Is it possible?

DataStream> pointsWithGridCoordinates;



Regards,
Subash Basnet

counting elements in datastream

[subash basnet]

Hello all,

There is *count()* function in database to count the number of elements in
the dataset. But it's not there in case of datastream. What could be the
way to count the number of elements in case of datastream.



Best Regards,
Subash Basnet