[ 
https://issues.apache.org/jira/browse/HDFS-3429?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

LiuLei updated HDFS-3429:
-------------------------

    Attachment: hdfs-3429-0.20.2.patch

The new patch for 0.20.2, include below content
1. Fix the TestDataTransferProtocol unit test
2. Modify the DataTransferProtocol.DATA_TRANSFER_VERSION value to 18
                
> DataNode reads checksums even if client does not need them
> ----------------------------------------------------------
>
>                 Key: HDFS-3429
>                 URL: https://issues.apache.org/jira/browse/HDFS-3429
>             Project: Hadoop HDFS
>          Issue Type: Bug
>          Components: data-node, performance
>    Affects Versions: 2.0.0-alpha
>            Reporter: Todd Lipcon
>            Assignee: Todd Lipcon
>         Attachments: hdfs-3429-0.20.2.patch, hdfs-3429-0.20.2.patch, 
> hdfs-3429.txt, hdfs-3429.txt, hdfs-3429.txt
>
>
> Currently, even if the client does not want to verify checksums, the datanode 
> reads them anyway and sends them over the wire. This means that performance 
> improvements like HBase's application-level checksums don't have much benefit 
> when reading through the datanode, since the DN is still causing seeks into 
> the checksum file.
> (Credit goes to Dhruba for discovering this - filing on his behalf)

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Reply via email to