Horton

Re: BUG #15346: Replica fails to start after the crash

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: pgsql-bugs@lists.postgresql.org,Michael Paquier <michael@paquier.xyz>,Alexander Kukushkin <cyberdemn@gmail.com>
Cc: Alvaro Herrera <alvherre@2ndquadrant.com>,Dmitry Dolgov <9erthalion6@gmail.com>
Date: 2018-08-28T05:08:33Z
Lists: pgsql-bugs, pgsql-hackers 

On August 28, 2018 11:44:09 AM GMT+09:00, Michael Paquier <michael@paquier.xyz> wrote:
>On Sat, Aug 25, 2018 at 09:54:39AM +0200, Alexander Kukushkin wrote:
>> Why the number of tuples in the xlog is greater than the number of
>> tuples on the index page?
>> Because this page was already overwritten and its LSN is HIGHER than
>> the current LSN!
>
>That's annoying.  Because that means that the control file of your
>server maps to a consistent point which is older than some of the
>relation pages.  How was the base backup of this node created?  Please
>remember that when taking a base backup from a standby, you should
>backup the control file last, as there is no control of end backup with
>records available.  So it seems to me that the origin of your problem
>comes from an incorrect base backup expectation? 

Uh, where is that "control file last" bit coming from?

Andres
-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.

Commits

  1. Ensure correct minimum consistent point on standbys

  2. Prevent references to invalid relation pages after fresh promotion