FAQ
Hi all,

I had some queries :

1) In a Hadoop cluster, when I write a file into HDFS, the replication
factor that's followed - is it corresponding to the dfs.replication
parameter set in hdfs-site.xml file in the master ? Or should
something else be done about that (like changing the dfs.replication
parameter of all the nodes in the cluster by editing the xml file ?)

2) dfs.replication = 2 does that mean there are 2 replicates and a
total of 3 copies / does that mean total number of copies = 2 ?

Thanks,
Ankita

Search Discussions

  • Harsh J at Mar 8, 2011 at 6:02 am
    Hello,

    On Tue, Mar 8, 2011 at 11:16 AM, Ankita Kalantri
    wrote:
    1) In a Hadoop cluster, when I write a file into HDFS, the replication
    factor that's followed - is it corresponding to the dfs.replication
    parameter set in hdfs-site.xml file in the master ? Or should
    something else be done about that (like changing the dfs.replication
    parameter of all the nodes in the cluster by editing the xml file ?)
    Having the replication config on the master should be sufficient (it
    is used at the NameNode, for default value purposes). But replication
    is a file-level property, and can be controlled at the code level
    while creating files and may be reset anytime to a different values
    for existing files also (Try `hadoop dfs -setrep` for an example).
    2) dfs.replication = 2 does that mean there are 2 replicates and a
    total of 3 copies / does that mean total number of copies = 2 ?
    Replication=2 means One original block + One replica. It is the total.

    --
    Harsh J
    www.harshj.com

Related Discussions

Discussion Navigation
viewthread | post
Discussion Overview
groupcommon-user @
categorieshadoop
postedMar 8, '11 at 5:47a
activeMar 8, '11 at 6:02a
posts2
users2
websitehadoop.apache.org...
irc#hadoop

2 users in discussion

Ankita Kalantri: 1 post Harsh J: 1 post

People

Translate

site design / logo © 2022 Grokbase