Hadoop dfs replicate

Question

Sorry guys,just a simple question but I cannot find exact question on google. The question about what\'s dfs.replication mean? If I made one file named filmdata.txt in hdfs,

Answer 1

To ensure high availability of data, Hadoop replicates the data.

When we are storing the files into HDFS, hadoop framework splits the file into set of blocks( 64 MB or 128 MB) and then these blocks will be replicated across the cluster nodes.The configuration dfs.replication is to specify how many replications are required.

The default value for dfs.replication is 3, But this is configurable depends on your cluster setup.

Hope this helps.