[HDFS-3071] haadmin failover command does not provide enough detail for when target NN is not ready to be active

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.0-alpha
• Fix Version/s: 2.0.0-alpha
• Component/s: ha
• Hadoop Flags: Reviewed
• Assignee: Todd Lipcon
• Reporter: Philip Martin
• Created: 09/Mar/12 01:44
• Updated: 28/Sep/15 20:58
• Resolved: 23/Mar/12 06:30

Description

When running the failover command, you can get an error message like the following:

$ hdfs --config $(pwd) haadmin -failover namenode2 namenode1
Failover failed: xxx.yyy/1.2.3.4:8020 is not ready to become active

Unfortunately, the error message doesn't describe why that node isn't ready to be active. In my case, the target namenode's logs don't indicate anything either. It turned out that the issue was "Safe mode is ON.Resources are low on NN. Safe mode must be turned off manually.", but ideally the user would be told that at the time of the failover.

Issue Links

• breaks: HDFS-3132 Findbugs warning on HDFS trunk