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Date: Fri, 20 Apr 2012 19:20:39 +0100
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 <CAEccTyzdGytbVeeFB2mOoxHecaT__ggCrsRJXQE4mCMvq8yzaw@mail.gmail.com>
Subject: Re: shortest-path maintenance
From: Sean Owen <srowen@gmail.com>
To: user@mahout.apache.org
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That's fair. I do think Pregel is more complex too, but for many
problems probably lets you express the solution more succinctly.
Hadoop jobs are hard to write and understand and debug. Most of the
reason I'm still into Hadoop is just practical: it's that much more
mature.

Among the many ideas floating around like this, here's a relatively
interesting one from MS Research, Ciel:
http://research.microsoft.com/apps/pubs/default.aspx?id=3D155149

On Fri, Apr 20, 2012 at 7:16 PM, Mike Spreitzer <mspreitz@us.ibm.com> wrote=
:
> I, too, think there is not one best paradigm for everything. =C2=A0Howeve=
r, it
> seems to me that Pregel-for-key-value-data, if I may call it that,
> dominates map-reduce except for applications where you really need the
> sorting built into map-reduce (and if you think about it, many things for
> which map-reduce is being used do not really need that sorting). =C2=A0As=
ide
> from that sorting, map-reduce is just a subset of what you can do with
> Pregel-for-key-value-data. =C2=A0And sorting could be added to the richer
> programming model, so it would be a strict dominance situation --- for
> this particular pair of paradigms. =C2=A0Wouldn't you agree?
>
> The maintenance problem I cited is one that looks like it would really
> demonstrate some of the value of the richer programming model. =C2=A0I wo=
uld
> like to try an actual comparison. =C2=A0To be fair, the map-reduce based
> solution should not be stupid. =C2=A0So that's why I am asking how this
> maintenance problem can best be solved using map-reduce.
>
> Thanks,
> Mike