El 3/10/2011 8:37 AM, Rita escribió:
Thanks Stu. I too was sure there was an algorithm. Is there a place
where I can read more about it? I want to know if it picks a block
according to the load average or does it always pick "rack0" first?
On Wed, Mar 9, 2011 at 10:24 PM, <stu24m...@yahoo.com
<mailto:stu24m...@yahoo.com>> wrote:
There is an algorithm. Each block should have a copy on different
nodes. In your case, each block will have a copy on each of the nodes.
Take care,
-stu
------------------------------------------------------------------------
*From: * Rita <rmorgan...@gmail.com <mailto:rmorgan...@gmail.com>>
*Date: *Wed, 9 Mar 2011 22:07:37 -0500
*To: *<hdfs-user@hadoop.apache.org
<mailto:hdfs-user@hadoop.apache.org>>
*ReplyTo: * hdfs-user@hadoop.apache.org
<mailto:hdfs-user@hadoop.apache.org>
*Subject: *how does hdfs determine what node to use?
I have a 2 rack cluster. All of my files have a replication factor
of 2. How does hdfs determine what node to use when serving the
data? Does it always use the first rack? or is there an algorithm
for this?
--
--- Get your facts first, then you can distort them as you please.--
--
--- Get your facts first, then you can distort them as you please.--
The best source that I found for this is the Tom White´s book: Hadoop:
The Definitive Guide 2nd Edition. Chapter 3: The Hadoop Distributed
FileSystem, and the Hadoop wiki: http://wiki.apache.org/hadoop/HDFS.
Regards
--
Marcos Luís Ortíz Valmaseda
Software Engineer
Universidad de las Ciencias Informáticas
Linux User # 418229
http://uncubanitolinuxero.blogspot.com
http://www.linkedin.com/in/marcosluis2186
