I am going through the chapter "How mapreduce works" and have some
confusion:
1) Below description of Mapper says that reducers get the output file using
HTTP call. But the description under "The Reduce Side" doesn't specifically
say if it's copied using HTTP. So first confusion, Is the output cop
Answers inline.
On Wed, Apr 4, 2012 at 4:56 PM, Mohit Anchlia wrote:
> I am going through the chapter "How mapreduce works" and have some
> confusion:
>
> 1) Below description of Mapper says that reducers get the output file using
> HTTP call. But the description under "The Reduce Side" doesn't s
On Wed, Apr 4, 2012 at 5:23 PM, Prashant Kommireddi wrote:
> Answers inline.
>
> On Wed, Apr 4, 2012 at 4:56 PM, Mohit Anchlia >wrote:
>
> > I am going through the chapter "How mapreduce works" and have some
> > confusion:
> >
> > 1) Below description of Mapper says that reducers get the output f
Hi Mohit,
On Thu, Apr 5, 2012 at 5:26 AM, Mohit Anchlia wrote:
> I am going through the chapter "How mapreduce works" and have some
> confusion:
>
> 1) Below description of Mapper says that reducers get the output file using
> HTTP call. But the description under "The Reduce Side" doesn't specifi
On Wed, Apr 4, 2012 at 8:42 PM, Harsh J wrote:
> Hi Mohit,
>
> On Thu, Apr 5, 2012 at 5:26 AM, Mohit Anchlia
> wrote:
> > I am going through the chapter "How mapreduce works" and have some
> > confusion:
> >
> > 1) Below description of Mapper says that reducers get the output file
> using
> > HT
Hi Mohit,
What would be the advantage? Reducers in most cases read data from all
the mappers. In the case where mappers were to write to HDFS, a
reducer would still require to read data from other datanodes across
the cluster.
Prashant
On Apr 4, 2012, at 9:55 PM, Mohit Anchlia wrote:
> On Wed,
On Wed, Apr 4, 2012 at 10:02 PM, Prashant Kommireddi wrote:
> Hi Mohit,
>
> What would be the advantage? Reducers in most cases read data from all
> the mappers. In the case where mappers were to write to HDFS, a
> reducer would still require to read data from other datanodes across
> the cluster.
On Thu, Apr 5, 2012 at 7:03 AM, Mohit Anchlia wrote:
> Only advantage I was thinking of was that in some cases reducers might be
> able to take advantage of data locality and avoid multiple HTTP calls, no?
> Data is anyways written, so last merged file could go on HDFS instead of
> local disk.
> I
