[
https://issues.apache.org/jira/browse/HADOOP-8233?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16386728#comment-16386728
]
Steve Loughran commented on HADOOP-8233:
----------------------------------------
* 0-byte length can be skipped
* blocksize is trouble, as for filesystems != HDFS, there's no guarantee that
different blocksize ==> Different checksum.
> Turn CRC checking off for 0 byte size and differing blocksizes
> --------------------------------------------------------------
>
> Key: HADOOP-8233
> URL: https://issues.apache.org/jira/browse/HADOOP-8233
> Project: Hadoop Common
> Issue Type: Bug
> Affects Versions: 0.23.3
> Reporter: Dave Thompson
> Assignee: Dave Thompson
> Priority: Major
> Attachments: HADOOP-8233-branch-0.23.2.patch
>
>
> DistcpV2 (hadoop-tools/hadoop-distcp/..) can fail from checksum failure,
> sometimes when copying a 0 byte file. Root cause of this may have to do
> with an inconsistent nature of HDFS when creating 0 byte files, however
> distcp can avoid this issue by not checking CRC when size is zero.
> Further, distcp fails checksum when copying from two clusters that use
> different blocksizes. In this case it does not make sense to check CRC, as
> it is a guaranteed failure.
> We need to turn CRC checking off for the above two cases.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: common-issues-h...@hadoop.apache.org
