Server failure. HBase can still read HFiles written in the older version 2 format.
Need a script that user can run pre-upgrade.
Additional commentary from Sean Busbey
In addition to the config check stack mentions, such a tool could check
- other problematic configs, like those for master-hosts-regions
- inconsistent configs due to changed defaults (I think we should have some smell-tests around the change in default for hbase.security.authorization)
- (optionally) check for unreadable WALs
- (optionally) check for unreadable hfiles