[HDFS-2820] Add a simple sanity check for HA config

• Type: Sub-task
• Status: Resolved
• Priority: Trivial
• Resolution: Fixed
• Affects Version/s: HA branch (HDFS-1623)
• Fix Version/s: HA branch (HDFS-1623)
• Component/s: ha, namenode
• Target Version/s: HA branch (HDFS-1623)
• Hadoop Flags: Reviewed
• Assignee: Todd Lipcon
• Reporter: Todd Lipcon
• Created: 21/Jan/12 00:25
• Updated: 15/Sep/14 05:09
• Resolved: 23/Jan/12 21:49

Description

If the user configures a shared edits dir, but doesn't configure the namenode addresses correctly, the NN will fail to start up in a very strange way.
I had this misconfiguration in one of my test clusters which was difficult to debug, even though I'm very familiar with the code. This patch is to add a simple sanity check so that if a user has the same misconfiguration, it will fail to start and given a more informative dump.