Horton

Re: standby recovery fails (tablespace related) (tentative patch and discussion)

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>, Michael Paquier <michael@paquier.xyz>, Julien Rouhaud <rjuju123@gmail.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2022-04-01T18:51:58Z
Lists: pgsql-hackers 
On Fri, Apr 1, 2022 at 12:22 AM Kyotaro Horiguchi
<horikyota.ntt@gmail.com> wrote:
> By the way, may I ask how do we fix this?  The existing recovery code
> already generates just-to-be-delete files in a real directory in
> pg_tblspc sometimes, and elsewise skip applying WAL records on
> nonexistent heap pages.  It is the "mixed" way.

Can you be more specific about where we have each behavior now?

> 1. stop XLogReadBufferForRedo creating a file in nonexistent
>   directories then remember the failure (I'm not sure how big the
>   impact is.)
>
> 2. unconditionally create all objects required for recovery to proceed..
>   2.1 and igore the failures.
>   2.2 and remember the failures.
>
> 3. Any other?
>
> 2 needs to create a real directory in pg_tblspc. So 1?

I think we could either do 1 or 2. My intuition is that getting 2
working would be less scary and more likely to be something we would
feel comfortable back-patching, but 1 is probably a better design in
the long term. However, I might be wrong -- that's just a guess.

-- 
Robert Haas
EDB: http://www.enterprisedb.com

Commits

  1. Improve recently-added test reliability

  2. Fix new recovery test for log_error_verbosity=verbose case

  3. Fix test instability

  4. Fix replay of create database records on standby

  5. Allow "in place" tablespaces.

  6. Fix get_dirent_type() for Windows junction points.

  7. Revert "Fix replay of create database records on standby"

  8. Add end-to-end testing of pg_basebackup's tar-format output.

  9. Make DROP DATABASE command generate less WAL records.

  10. Consolidate methods for translating a Perl path to a Windows path.