Horton

Re: [Patch] pg_rewind: options to use restore_command from recovery.conf or command line

Michael Paquier <michael@paquier.xyz>

View thread
From: Michael Paquier <michael@paquier.xyz>
To: Alexey Kondratov <a.kondratov@postgrespro.ru>
Cc: Alexander Korotkov <a.korotkov@postgrespro.ru>, Alvaro Herrera <alvherre@2ndquadrant.com>, Liudmila Mantrova <l.mantrova@postgrespro.ru>, Thomas Munro <thomas.munro@gmail.com>, Andrey Borodin <x4mmm@yandex-team.ru>, David Steele <david@pgmasters.net>, Andres Freund <andres@anarazel.de>, PostgreSQL-development <pgsql-hackers@postgresql.org>, Dmitry Dolgov <9erthalion6@gmail.com>, vladimirlesk@yandex-team.ru, dsarafan@yandex-team.ru
Date: 2020-03-04T07:45:55Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Move frontend-side archive APIs from src/common/ to src/fe_utils/

  2. Add -c/--restore-target-wal to pg_rewind

  3. Move routine definitions of xlogarchive.c to a new header file

  4. Move routine building restore_command to src/common/

  5. Integrate recovery.conf into postgresql.conf

Attachments

On Mon, Mar 02, 2020 at 08:59:49PM +0300, Alexey Kondratov wrote:
> OK, sounds reasonable, but just to be clear. I will remove only a
> possibility to bypass this sanity check (with 0), but leave expectedSize
> argument intact. We still need it, since pg_rewind takes WalSegSz from
> ControlFile and should pass it further, am I right?

We need to keep around the argument, but I think that we give any user
of this routine a favor by making mandatory a file size.

> pg_strip_crlf fits well, but would you mind if I also make pipe_read_line
> external in this patch?

I got to look at that more, and pipe_read_line() is a nice fit.

> Actually, the verb 'construct' is used historically applied to
> archive/restore commands (see also xlogarchive.c and pgarch.c), but it
> should be 'build' in (fe_)archive.c, since we have BuildRestoreCommand there
> now.
> 
> All other remarks look clear for me, so I fix them in the next patch
> version, thanks.

Already done as per the attached, with a new routine named
getRestoreCommand() and more done.  There were a couple of extra
things I noticed on the way:
- Found some typos.
- The translation of pg_rewind --help was incorrect, with a sentence
cut in the middle (you used twice gettext).
- I did not actually get why you don't check for a missing command
when using wait_result_is_any_signal.  In this case I'd think that it
is better to exit immediately as follow-up calls would just fail.
- The code was rather careless about error handling and
RestoreArchivedWALFile(), and it seemed to me that it is rather
pointless to report an extra message "could not restore file \"%s\"
from archive" on top of the other error.
- I could not resist to add more documentation for the new routines of
src/common/..
- Used long options in the tests for readability, reworked the
comments.

On top of that, I have spent some time testing the reliability of the
test, and tested the whole on Windows and Linux.  This is in a rather
committable shape now.
--
Michael