Horton

Re: hung backends stuck in spinlock heavy endless loop

Merlin Moncure <mmoncure@gmail.com>

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From: Merlin Moncure <mmoncure@gmail.com>
To: Peter Geoghegan <pg@heroku.com>
Cc: Andres Freund <andres@2ndquadrant.com>, Tom Lane <tgl@sss.pgh.pa.us>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2015-01-14T23:38:45Z
Lists: pgsql-hackers 
On Wed, Jan 14, 2015 at 2:32 PM, Peter Geoghegan <pg@heroku.com> wrote:
> On Wed, Jan 14, 2015 at 12:24 PM, Peter Geoghegan <pg@heroku.com> wrote:
>> Could you write some code to print out the block number (i.e.
>> "BlockNumber blkno") if there are more than, say, 5 retries within
>> _bt_moveright()?
>
> Obviously I mean that the block number should be printed, no matter
> whether or not the P_INCOMPLETE_SPLIT() path is taken or not. So you
> should just move this to the top of the for(;;) loop, so it's always
> available to print:
>
> BlockNumber blkno = BufferGetBlockNumber(buf);

(gdb) print  BufferGetBlockNumber(buf)
$15 = 9

..and it stays 9, continuing several times having set breakpoint.

merlin

Commits

  1. Improve hash_create's API for selecting simple-binary-key hash functions.

  2. Fix WAL-logging of B-tree "unlink halfdead page" operation.

  3. Fix backup-block numbering in redo of b-tree split.

  4. Cleanup of new b-tree page deletion code.

  5. Fix bug in the new B-tree incomplete-split code.

  6. Fix bug in new B-tree page deletion code.

  7. Fix rm_desc routine of b-tree page delete records.

  8. Make the handling of interrupted B-tree page splits more robust.

  9. Fix race condition in B-tree page deletion.