hadoopIntroduction to MapReduce


Syntax

  • To run the example, the command syntax is:

    bin/hadoop jar hadoop-*-examples.jar wordcount [-m <#maps>] [-r <#reducers>] <in-dir> <out-dir>
    
  • To copy data into HDFS(from local):

    bin/hadoop dfs -mkdir <hdfs-dir> //not required in hadoop 0.17.2 and later
    bin/hadoop dfs -copyFromLocal <local-dir> <hdfs-dir>
    

Remarks

Word Count program using MapReduce in Hadoop.