Re: Questions about the continuity of WAL archiving

On 8/7/25 22:50, px shi wrote:
> Thank you for your reply.
> The archived files can be used for PITR (Point-In-Time Recovery),
> allowing recovery to any point between WAL 80 and 100 on timeline 1.
> Additionally, if there's a backup taken during timeline 1 and a
> switchover to a new primary has occurred without taking a new full
> backup yet, these WAL logs can still be used to recover to any point on
> timeline 2.

Alright I see.

Two things:

1) What is the current archiving setup on the primary and why is lagging?

2) Have you looked at archiving off the standby node while it is in
standby per:

https://www.postgresql.org/docs/current/warm-standby.html#CONTINUOUS-ARCHIVING-IN-STANDBY

>
> Regards,
> Pixian Shi
>
> Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com
> <mailto:adrian(dot)klaver(at)aklaver(dot)com>> 于2025年8月8日周五 12:25写道：
>
> On 8/7/25 20:20, px shi wrote:
> > Hi,
> > There is a scenario: the current timeline of the PostgreSQL
> primary node
> > is 1, and the latest WAL file is 100. The standby node has also
> received
> > up to WAL file 100. However, the latest WAL file archived is only
> file
> > 80. If the primary node crashes at this point and the standby is
> > promoted to the new primary, archiving will resume from file 100 on
> > timeline 2. As a result, WAL files from 81 to 100 on timeline 1
> will be
> > missing from the archive.
>
> What are you planning to do with the archived files?
>
> Also is not the case that once the primary crashes you are in a split
> brain case and can't really trust it's timeline anymore?
>
>
> > Is there a good solution to prevent this situation?
> >
> > Regards,
> > Pixian Shi
>
>
> --
> Adrian Klaver
> adrian(dot)klaver(at)aklaver(dot)com <mailto:adrian(dot)klaver(at)aklaver(dot)com>
>

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