[HADOOP-112] copyFromLocal should exclude .crc files

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 0.1.0

Environment

DFS cluster of 6 3hz Xeons with 2Gb RAM running Centos 4.2 and Sun's JDK1.5 - but Probably applies in any environment

• Assignee: Doug Cutting
• Reporter: Monu Ogbe
• Created: 30/Mar/06 23:25
• Updated: 08/Jul/09 16:41
• Resolved: 08/Apr/06 08:03

Description

Doug Cutting says: "The problem is that when copyFromLocal
enumerates local files it should exclude .crc files, but it does not.
This is the listFiles() call on DistributedFileSystem:160. It should
filter this, excluding files that are FileSystem.isChecksumFile().

BTW, as a workaround, it is safe to first remove all of the .crc files,
but your files will no longer be checksummed as they are read. On
systems without ECC memory file corruption is not uncommon, but I have
seen very little on clusters that have ECC."

Original observations:

Hello Team,

I created a backup of my DFS database:

1. bin/hadoop dfs -copyToLocal /user/root/crawl /mylocaldir

I now want to restore from the backup using:

1. bin/hadoop dfs -copyFromLocal /mylocaldir/crawl /user/root

However I'm getting the following error:

copyFromLocal: Target /user/root/crawl/crawldb/current/part-00000/.data.crc
already exists

I get this message with every permutation of the command that I've tried, and
even after totally deleting all content in the DFS directories.

I'd be grateful for any pointers.

Many thanks,