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From Neil Jonkers <neilod...@gmail.com>
Subject Re: A quick question about replication factor
Date Thu, 18 Dec 2014 14:49:12 GMT

With dfs.replication = 3, each block making up the file on HDFS, will have three copies on
three distinct data nodes. Hence at any point you can loose two data nodes, the name node
would know the address of the third block, no problem. In this scenario HDFS will replicate
the block again to ensure the dfs.replication factor holds true. The replication pipeline
describe the process where blocks are replicated to comply with dfs.replication factor.

Hadoop fs -ls -l /hdfs_file

Will show you the replication factor of file in HDFS.

You can view the details of the blocks making up HDFS file with:

hadoop  fsck / -files -blocks |grep hdfs_file_name -A 30

Hope this help


<div>-------- Original message --------</div><div>From: bit1129@163.com
</div><div>Date:18/12/2014  15:40  (GMT+02:00) </div><div>To: user
<user@hadoop.apache.org> </div><div>Subject: A quick question about replication
factor </div><div>
</div>Hi Hadoopers,
If I configure the replication factor to be 3 in the configuration file, then how many blocks
of the same have been stored? Three or Four.

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