[HBASE-22347] try to archive WALs when closing a region or when shutting down RS

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: regionserver, wal
• Labels: wal
• Assignee: Unassigned
• Reporter: Sergey Shelukhin
• Created: 01/May/19 18:08
• Updated: 03/May/19 18:48

Description

When RS shuts down in an orderly manner due to an upgrade or decom, even it has 0 regions (discovered when testing HBASE-22254), it still dies with some active WALs.
WALs are then split by master, and in the 0-region case the recovered edits are not used for anything. This splitting is a waste of time... if some region is moved away from the server it might also make sense to archive the WALs to avoid reading the extras.
RS shutdown should archive WALs if possible after flushing/closing regions; given that the latter can fail, perhaps once before, and once after.
Closing a region via an RPC should also try to archive WAL.