[HBASE-8348] Polish the migration to 0.96

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 0.95.0
• Fix Version/s: 0.96.0
• Hadoop Flags: Reviewed
• Release Note: Added upgrade script that must be run moving a 0.92.x or 0.94.x era hbase dataset to 0.96.x
• Assignee: rajeshbabu
• Reporter: Jean-Daniel Cryans
• Created: 15/Apr/13 22:55
• Updated: 20/Nov/15 11:53
• Resolved: 20/Sep/13 17:46

Description

Currently, migration works but there's still a couple of rough edges:

• HBASE-8045 finished the .META. migration but didn't remove ROOT, so it's still on the filesystem.
• Data in ZK needs to be removed manually. Either we fix up the data in ZK or we delete it ourselves.
• TestMetaMigrationRemovingHTD has a testMetaUpdatedFlagInROOT method, but ROOT is gone now.

Elliott was also mentioning that we could have "hbase migrate" do the HFileV1 checks, clear ZK, remove ROOT, etc.

Issue Links

• incorporates: HBASE-7766 master cannot go from 94 to 96 due to zookeeper data
• is blocked by: HBASE-9134 Run NamespaceUpgrade from hbase migration script
• relates to: HBASE-9110 Meta region edits not recovered while migrating to 0.96.0
• relates to: HBASE-9278 Reading Pre-namespace meta table edits kills the reader
• relates to: HBASE-9177 Cluster UUID is not properly parsable after rewriting to PB.
• relates to: HBASE-8778 Region assigments scan table directory making them slow for huge tables