On 2022-Jun-09, Stephen Frost wrote:
> TL;DR: if you're removing files from a directory that you've got an
> active readdir() running through, you might not actually get all of the
> *existing* files. Given that PG is happy to remove files from PGDATA
> while a backup is running, in theory this could lead to a backup utility
> like pgbackrest or pg_basebackup not actually backing up all the files.
>
> Now, pgbackrest runs the readdir() very quickly to build a manifest of
> all of the files to backup, minimizing the window for this to possibly
> happen, but pg_basebackup keeps a readdir() open during the entire
> backup, making this more possible.
Hmm, this sounds pretty bad, and I agree that a workaround should be put
in place. But where is pg_basebackup looping around readdir()? I
couldn't find it. There's a call to readdir() in FindStreamingStart(),
but that doesn't seem to match what you describe.
--
Álvaro Herrera 48°01'N 7°57'E — https://www.EnterpriseDB.com/