[HDFS-1969] Running rollback on new-version namenode destroys namespace

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 0.22.0
• Fix Version/s: 0.22.0
• Component/s: namenode
• Hadoop Flags: Reviewed
• Assignee: Todd Lipcon
• Reporter: Todd Lipcon
• Created: 20/May/11 04:33
• Updated: 10/May/12 05:00
• Resolved: 06/Jun/11 05:29

Description

The following sequence leaves the namespace in an inconsistent/broken state:

• format NN using 0.20 (or any prior release, probably)
• run hdfs namenode -upgrade on 0.22. ^C the NN once it comes up.
• run hdfs namenode -rollback on 0.22 (this should fail but doesn't!)

This leaves the name directory in a state such that the version file claims it's an 0.20 namespace, but the fsimage is in 0.22 format. It then crashes when trying to start up.

Issue Links

• relates to: HDFS-3393 Rollback on newer release must not be allowed if the layout version in the snapshot is for older release.