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From Duy Huynh <duy.huynh....@gmail.com>
Subject Re: why is spark + scala code so slow, compared to python?
Date Thu, 11 Dec 2014 19:18:35 GMT
both.

first, the distributed version is so much slower than python.  i tried a
few things like broadcasting variables, replacing Seq with Array, and a few
other little things.  it helps to improve the performance, but still slower
than the python code.

so, i wrote a local version that's pretty much just running a bunch of
breeze/blas operations.  i guess that's purely scala (no spark).  this
local version is faster than the distributed version but still much slower
than the python code.







On Thu, Dec 11, 2014 at 2:09 PM, Natu Lauchande <nlauchande@gmail.com>
wrote:

> Are you using Scala in a distributed enviroment or in a standalone mode ?
>
> Natu
>
> On Thu, Dec 11, 2014 at 8:23 PM, ll <duy.huynh.uiv@gmail.com> wrote:
>
>> hi.. i'm converting some of my machine learning python code into scala +
>> spark.  i haven't been able to run it on large dataset yet, but on small
>> datasets (like http://yann.lecun.com/exdb/mnist/), my spark + scala code
>> is
>> much slower than my python code (5 to 10 times slower than python)
>>
>> i already tried everything to improve my spark + scala code like
>> broadcasting variables, caching the RDD, replacing all my matrix/vector
>> operations with breeze/blas, etc.  i saw some improvements, but it's
>> still a
>> lot slower than my python code.
>>
>> why is that?
>>
>> how do you improve your spark + scala performance today?
>>
>> or is spark + scala just not the right tool for small to medium datasets?
>>
>> when would you use spark + scala vs. python?
>>
>> thanks!
>>
>>
>>
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>

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