[HBASE-15441] Fix WAL splitting when region has moved multiple times

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 1.1.0, 1.2.0
• Fix Version/s: 1.3.0, 1.2.1, 2.0.0
• Component/s: Recovery, wal
• Labels: needs_releasenote
• Assignee: Elliott Neil Clark
• Reporter: Elliott Neil Clark
• Created: 10/Mar/16 21:29
• Updated: 09/Nov/17 00:18
• Resolved: 16/Mar/16 23:38

Description

Currently WAL splitting is broken when a region has been opened multiple times in recent minutes.

Region open and region close write event markers to the wal. These markers should have the sequence id in them. However it is currently getting 1. That means that if a region has moved multiple times in the last few mins then multiple split log workers will try and create the recovered edits file for sequence id 1. One of the workers will fail and on failing they will delete the recovered edits. Causing all split wal attempts to fail.

We need to:

1. make sure that close get the correct sequence id for open.
2. Filter all region events from recovered edits

It appears that the close event with a sequence id of one is coming from region warm up.