[HBASE-7294] Check for snapshot file cleaners on start

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: hbase-6055
• Fix Version/s: 0.95.0
• Component/s: Client, master, regionserver, snapshots, Zookeeper
• Hadoop Flags: Reviewed
• Assignee: Matteo Bertozzi
• Reporter: Jesse Yates
• Created: 06/Dec/12 23:49
• Updated: 23/Sep/13 18:31
• Resolved: 29/Dec/12 19:04

Description

Snapshots currently use the SnaphotHfileCleaner and SnapshotHLogCleaner to ensure that any hfiles or hlogs (respectively) that are currently part of a snapshot are not removed from their respective archive directories (.archive and .oldlogs).

From Matteo Bertozzi:

currently the snapshot cleaner is not in hbase-default.xml
and there's no warning/exception on snapshot/restore operation, if not enabled.

even if we add the cleaner to the hbase-default.xml how do we ensure that the user doesn't remove it?
Do we want to hardcode the cleaner at master startup?
Do we want to add a check in snapshot/restore that throws an exception if the cleaner is not enabled?