Get an aggregator's value outside of an iteration

classic Classic list List threaded Threaded
3 messages Options
Reply | Threaded
Open this post in threaded view
|

Get an aggregator's value outside of an iteration

Kien Truong
Hi,

I'm looking for a way get the value of aggregators outside of iteration.
Specifically, I want the final aggregators' value after the iteration
has finished. Is there any API for that ?

Thanks,
Kien Truong
Reply | Threaded
Open this post in threaded view
|

Re: Get an aggregator's value outside of an iteration

Aljoscha Krettek
Hi,
I’m afraid there is no way right now to get at the values of aggregators. I think implementing this is problematic since the aggregators from the different parallel instances of operators are only combined on the JobManager (master node).

Cheers,
Aljoscha
> On 27 Nov 2015, at 23:04, Truong Duc Kien <[hidden email]> wrote:
>
> Hi,
>
> I'm looking for a way get the value of aggregators outside of iteration. Specifically, I want the final aggregators' value after the iteration has finished. Is there any API for that ?
>
> Thanks,
> Kien Truong

Reply | Threaded
Open this post in threaded view
|

Re: Get an aggregator's value outside of an iteration

Stephan Ewen
We wanted to combine the accumulators and aggregators for a while, but have not gotten to it so far (there is a pending PR which needs some more work).

You can currently work your way around this by using the accumulators together with the aggregators.
  - Aggregators: Within an iteration across supersteps
  - Accumulators: Across one job, retrievable at the end in the client

You can use the close() method of a function (close() is called after each superstep) to take the aggregator value and put it into an accumulator. That accumulator can be retrieved after the job has finished.

Hope that workaround works for you!

Stephan


On Mon, Nov 30, 2015 at 10:51 AM, Aljoscha Krettek <[hidden email]> wrote:
Hi,
I’m afraid there is no way right now to get at the values of aggregators. I think implementing this is problematic since the aggregators from the different parallel instances of operators are only combined on the JobManager (master node).

Cheers,
Aljoscha
> On 27 Nov 2015, at 23:04, Truong Duc Kien <[hidden email]> wrote:
>
> Hi,
>
> I'm looking for a way get the value of aggregators outside of iteration. Specifically, I want the final aggregators' value after the iteration has finished. Is there any API for that ?
>
> Thanks,
> Kien Truong