Re: Incremental backup from a streaming replication standby fails

Laurenz Albe <laurenz.albe@cybertec.at>

From: Laurenz Albe <laurenz.albe@cybertec.at>
To: pgsql-hackers@postgresql.org
Date: 2024-07-15T15:26:58Z
Lists: pgsql-hackers
On Sat, 2024-06-29 at 07:01 +0200, Laurenz Albe wrote:
> I played around with incremental backup yesterday and tried $subject
> 
> The WAL summarizer is running on the standby server, but when I try  
> to take an incremental backup, I get an error that I understand to mean  
> that WAL summarizing hasn't caught up yet.
> 
> I am not sure if that is working as designed, but if it is, I think it  
> should be documented.

I played with this some more.  Here is the exact error message:

ERROR:  manifest requires WAL from final timeline 1 ending at 0/1967C260, but this backup starts at 0/1967C190

By trial and error I found that when I run a CHECKPOINT on the primary,
taking an incremental backup on the standby works.

I couldn't fathom the cause of that, but I think that that should either
be addressed or documented before v17 comes out.

Yours,
Laurenz Albe



Commits

  1. Document restrictions regarding incremental backups and standbys.