[HDFS-3612] Single namenode image directory config warning can be improved

• Type: Improvement
• Status: Closed
• Priority: Trivial
• Resolution: Fixed
• Affects Version/s: 2.0.0-alpha
• Fix Version/s: 2.0.2-alpha
• Component/s: namenode
• Labels: newbie
• Hadoop Flags: Reviewed
• Assignee: Andy Isaacson
• Reporter: Harsh J
• Created: 08/Jul/12 14:39
• Updated: 11/Oct/12 17:46
• Resolved: 13/Jul/12 07:21

Description

Currently, if you configure the NameNode to run with just one dfs.namenode.name.dir directory, it prints:

12/07/08 20:00:22 WARN namenode.FSNamesystem: Only one dfs.namenode.name.dir directory configured , beware data loss!

We can improve this in a few ways as it is slightly ambiguous:

1. Fix punctuation spacing, there's always a space after a punctuation mark but never before one.
2. Perhaps the message is better printed with a reason of why it may cause a scare of data loss. For instance, we can print "Detected a single storage directory in dfs.namenode.name.dir configuration. Beware of dataloss due to lack of redundant storage directories" or so.