

Three big myths about MapReduce - timf
http://www.dbms2.com/2009/10/18/three-big-myths-about-mapreduce/

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jfager
Strawman. Of course mapping followed by reducing isn't new, nobody serious
ever claimed that it was (the Dean & Ghemawat paper certainly doesn't).
Systems dedicated to performing map-reduce operations using giant clusters of
commodity hardware over tera/petabytes of data are, though, if for no other
reason than that the presence of and resources to economically store that much
data have only recently become widely available. MapReduce, as a term, refers
to those systems, not just the act of mapping and reducing.

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mumrah
For the longest time, after I read about MapReduce, I wondered what the big
fuss was about. MPI has equivalent functionality (Broadcast/Scatter and
Reduce) along with many other useful high-level communication functions. It
does restrict you to a limited (and unpopular) set of languages for web
programming though.

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vicaya
MapReduce is about hiding explicit parallel primitives like threads and MPI
from users (programmers): You only need to implement two functions map and
reduce in a typical framework.

Yes, you can certainly implement MapReduce with MPI partially, but typical
MapReduce framework like Hadoop also handles fault tolerance _transparently_
to users.

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mahmud
Good read:

 _Right now, this is a distinction pretty much without a difference. If you
choose an implementation of MapReduce — like pure Hadoop (say in the Cloudera
distribution) or Hadoop-Vertica or Aster Data’s SQL/MapReduce – you’re
basically picking an entire technology stack. But those stacks are going to do
a whole lot of changing and maturing in the near future – and as they do, it’s
likely that projects will interact or even combine in all sorts of interesting
ways._

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jmount
A good point, but while Map Reduce is not new I feel it emphasized clarity and
simplicity (at least for the problem of sorting), so that is probably why it
markets easier than MPI or a database. I wrote a bit on this point some time
ago: [http://www.win-vector.com/blog/2009/01/map-reduce-a-good-
ide...](http://www.win-vector.com/blog/2009/01/map-reduce-a-good-idea/)

