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Date: Mon, 30 Nov 2015 10:54:51 +0100
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 <CANC1h_t=57No2-uidyF=vHAMX6pRWOU9-DtrvQ8+BvuiTgeu=w@mail.gmail.com>
Subject: Re: Get an aggregator's value outside of an iteration
From: Stephan Ewen <sewen@apache.org>
To: user@flink.apache.org
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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 <aljoscha@apache.org>
wrote:

> Hi,
> I=E2=80=99m afraid there is no way right now to get at the values of aggr=
egators.
> 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 <duckientruong@gmail.com>
> 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
>
>

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<div dir=3D"ltr"><div>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).</div><div><br></div>You can currently work your way=
 around this by using the accumulators together with the aggregators.<div>=
=C2=A0 - Aggregators: Within an iteration across supersteps</div><div>=C2=
=A0 - Accumulators: Across one job, retrievable at the end in the client</d=
iv><div><br></div><div>You can use the close() method of a function (close(=
) is called after each superstep) to take the aggregator value and put it i=
nto an accumulator. That accumulator can be retrieved after the job has fin=
ished.</div><div><br></div><div>Hope that workaround works for you!</div><d=
iv><br></div><div>Stephan</div><div><br></div></div><div class=3D"gmail_ext=
ra"><br><div class=3D"gmail_quote">On Mon, Nov 30, 2015 at 10:51 AM, Aljosc=
ha Krettek <span dir=3D"ltr">&lt;<a href=3D"mailto:aljoscha@apache.org" tar=
get=3D"_blank">aljoscha@apache.org</a>&gt;</span> wrote:<br><blockquote cla=
ss=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;pa=
dding-left:1ex">Hi,<br>
I=E2=80=99m afraid there is no way right now to get at the values of aggreg=
ators. I think implementing this is problematic since the aggregators from =
the different parallel instances of operators are only combined on the JobM=
anager (master node).<br>
<br>
Cheers,<br>
Aljoscha<br>
<div class=3D"HOEnZb"><div class=3D"h5">&gt; On 27 Nov 2015, at 23:04, Truo=
ng Duc Kien &lt;<a href=3D"mailto:duckientruong@gmail.com">duckientruong@gm=
ail.com</a>&gt; wrote:<br>
&gt;<br>
&gt; Hi,<br>
&gt;<br>
&gt; I&#39;m looking for a way get the value of aggregators outside of iter=
ation. Specifically, I want the final aggregators&#39; value after the iter=
ation has finished. Is there any API for that ?<br>
&gt;<br>
&gt; Thanks,<br>
&gt; Kien Truong<br>
<br>
</div></div></blockquote></div><br></div>

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