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From "navaz" <navaz....@gmail.com>
Subject Client and NN communication in Hadoop
Date Thu, 27 Feb 2014 04:23:25 GMT


I have a Hadoop cluster running with 3 slaves and 1 Master. Slaves are
Datanodes and running Tasktarckers. Namenode is running jobtracker and
secondary namenode. I am running sample mapreduce after loading a file into


According to Hadoop architecture ,before writing a file into HDFS ,  client
will contact the Namenode and get the location details of DNs and then
client directly write the file into DN.  What is this client ? is it an
application running on Namenode ? Is user and client both are different ?
How can I see the messages between client and datanodes?


Appreciate your response.



Thanks & Regards


Abdul Navaz

Graduate Student

University of Houston Main Campus,Texas

Mob: (281) 685-0388


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