On 3/4/2012 5:44 AM, Kai Voigt wrote:
Hi,
please read http://developer.yahoo.com/hadoop/tutorial/module4.html#streaming
and http://developer.yahoo.com/hadoop/tutorial/module4.html#streaming for more
explanation and examples.
Kai
Am 04.03.2012 um 16:10 schrieb Lac Trung:
Can you give one or some examples about this, Kai ?
I haven't understood how Hadoop run a mapreduce program in other language :D
Vào 02:21 Ngày 04 tháng 3 năm 2012, Kai Voigt<k...@123.org> đã viết:
Hi,
the streaming API doesn't compile the streaming scripts.
The PHP/Perl/Python/Ruby scripts you create as mapper and reducer will be
called as external programs.
The input key/value pairs will be send to your scripts as stdin, and the
output will be collected from their stdout.
So, no compilation, the scripts will just be executed.
Kai
Am 04.03.2012 um 15:42 schrieb Lac Trung:
Hi everyone !
Hadoop is written in Java, so mapreduce programs are written in Java,
too.
But Hadoop provides an API to MapReduce that allows you to write your map
and reduce functions in languages other than Java (ex. Python), called
Hadoop Streaming.
I read the guide of Hadoop Streaming in
here<
http://www.hadoop.apache.org/common/docs/r0.15.2/streaming.html#More+usage+examples
but
I haven't seen any paragraph that write about converting language to
Java.
Can anybody tell me how Hadoop compile the program written in language
other than Java.
Thank you !
--
Lac Trung
--
Kai Voigt
k...@123.org
--
Lạc Trung
20083535
Its nothing out of ordinary.
The java routines written for your specific language ( Jruby, Jython )
etc. will interpret the code and run it.
No different from how Perl or Php work.
Thanks
