Re: Speedup twophase transactions

Nikhil Sontakke <nikhils@2ndquadrant.com>

From: Nikhil Sontakke <nikhils@2ndquadrant.com>
To: Michael Paquier <michael.paquier@gmail.com>
Cc: Stas Kelvich <s.kelvich@postgrespro.ru>, Simon Riggs <simon@2ndquadrant.com>, PostgreSQL mailing lists <pgsql-hackers@postgresql.org>, Jesper Pedersen <jesper.pedersen@redhat.com>, Robert Haas <robertmhaas@gmail.com>
Date: 2017-01-26T07:09:14Z
Lists: pgsql-hackers
>I look at this patch from you and that's present for me:
>https://www.postgresql.org/message-id/CAMGcDxf8Bn9ZPBBJZba9wiyQq->Qk5uqq=VjoMnRnW5s+fKST3w@mail.gmail.com

> --- a/src/backend/access/transam/xlog.c
> +++ b/src/backend/access/transam/xlog.c
> @@ -9573,6 +9573,7 @@ xlog_redo(XLogReaderState *record)
>                      (errmsg("unexpected timeline ID %u (should be %u)
> in checkpoint record",
>                              checkPoint.ThisTimeLineID, ThisTimeLineID)));
>
> +        KnownPreparedRecreateFiles(checkPoint.redo);
>          RecoveryRestartPoint(&checkPoint);
>      }

Oh, sorry. I was asking about CheckpointTwoPhase(). I don't see a
function by this name. And now I see, the name is CheckPointTwoPhase()
:-)

> And actually, when a XLOG_CHECKPOINT_SHUTDOWN record is taken, 2PC
> files are not flushed to disk with this patch. This is a problem as a
> new restart point is created... Having the flush in CheckpointTwoPhase
> really makes the most sense.

Umm, AFAICS, CheckPointTwoPhase() does not get called in the "standby
promote" code path.

Regards,
Nikhils
-- 
 Nikhil Sontakke                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services


Commits

  1. Speedup 2PC recovery by skipping two phase state files in normal path

  2. Add tests for two-phase commit

  3. Improve grammar of message about two-phase state files.

  4. Speedup 2PC by skipping two phase state files in normal path