Re: Postgres restore sometimes restores to a point 2 days in the past

On 1/31/25 12:10, Koen De Groote wrote:
> > What is the complete pg_basebackup command?

> 2/ All my WAL files are archived and uploaded to the cloud. So, I can
> just have them downloaded.

I should have asked earlier what is the archive command?

Are
> > What is determining that a particular WAL file should be asked for?
>
> The postgres server itself does this. Here's the documentation:
> https://www.postgresql.org/docs/16/runtime-config-wal.html#GUC-RESTORE-COMMAND <https://www.postgresql.org/docs/16/runtime-config-wal.html#GUC-RESTORE-COMMAND>
>
> And here: https://www.postgresql.org/docs/current/warm-standby.html
> <https://www.postgresql.org/docs/current/warm-standby.html>
>
> In practice, Postgres will see the "standby.signal" file and start

In your OP you say:

"It downloads the basebackup, unpacks it, sets a recovery.signal, ..."

Are you setting standby.signal or recovery.signal or both?

> asking for WAL files. It will read the database it has and determine
> what the next WAL filename should be. And then it asks for it. And it
> will keep asking for these hexadecimal filenames, 1 at a time, for as
> long as the command or set of commands provided to "restore_command"
> returns exit code 0. If the process receives any other exit code, it
> stops recovery, switches timeline, and considers the database to be up
> and running at the state its in.
>
> It's constantly asking "I want this file now" and the script I have as
> the restore command will attempt to download it from the cloud. Then it
> will attempt to unzip it and move it into place. If any of these steps
> fails, I return exit code 1.
>

> Regards,
> Koen De Groote
>
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com