[HBASE-3159] Double play of OpenedRegionHandler for a single region; fails second time through and aborts Master

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Fix Version/s: 0.90.0
• Hadoop Flags: Reviewed
• Assignee: Jonathan Gray
• Reporter: Michael Stack
• Created: 27/Oct/10 05:53
• Updated: 20/Nov/15 12:41
• Resolved: 28/Oct/10 21:33

Description

Here is master log with annotations: http://people.apache.org/~stack/master.txt

Region in question is:

b8827a67a9d446f345095d25e1f375f7

The running code is doctored in that I've added in a bit of logging – zk in particular – and I've also removed what I thought was a provocation of this condition, reassign inside in an assign if server has gone away when we try the open rpc (Turns out we have the condition even w/o this code in place).

The log starts where the region in question timesout in RIT.

We assign it to 186.

Notice how we see 'Handling transition' for this region TWICE. This means two OpenedRegionHandlers will be scheduled – and so the failure to delete a znode already gone.

As best I can tell, the watcher for this region is triggered once only – which is odd because how then the double scheduling of OpenedRegionHandler but also, why am I not seeing OPENING, OPENING, OPENED and only what I presume is an OPENED?