Changing Replication factor in hadoop on fly

Changing Replication factor in Hadoop on fly, the may be many time when you need to define replication factor of a specific file or directory on the fly, so following command will help you to change it.

The command used for this is "setrep"

How will you do it?

Solution :

Here are the steps :

Syntax :

• hadoop dfs -setrep [-R] <path>

    So this will change the replication factor of a file, and the optional [R] will ask to change the replication factor recursively.
    This will return 0, and -1 on failure.

Some Examples of the commnad:

•     hadoop dfs -setrep -w 2 /home/filename   <---- </home/filename is path of file on hdfs>

If you want to change recursively, of entire hdfs, or directory then you can user following command

    ./bin/hadoop dfs -setrep -R -w 2 /

This will change the replication recursively.