hadoop-hdfs-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "dhruba borthakur (JIRA)" <j...@apache.org>
Subject [jira] Created: (HDFS-1567) DFSClient should retry reading from all datanodes in round robin fashion
Date Tue, 04 Jan 2011 06:42:46 GMT
DFSClient should retry reading from all datanodes in round robin fashion
------------------------------------------------------------------------

                 Key: HDFS-1567
                 URL: https://issues.apache.org/jira/browse/HDFS-1567
             Project: Hadoop HDFS
          Issue Type: Improvement
          Components: hdfs client
            Reporter: dhruba borthakur


In the current implementation, the DFSClient retries the same datanode a few times (for reading)
before marking the datanode as "dead" and moving on to trying the read-request from the next
replica. This introduces additional delay when the first candidate datanode was really out-of-service.
Instead, it might be beneficial (for performance) to make the DFSClient retry all datanode
replicas one after another (while keeping the total number of retries per datanode the same
as now); if all the replicas were tried unsuccessfully once, then loop back to retrying the
first one and so on.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message