On 12/17/25 08:10, Colin 't Hart wrote:
Thanks Laurenz, that confirms what I was assuming. Archiving is via
pgbackrest to a backup server, over SSH. Approx 750ms to archive each
segment is crazy -- I'll check compression parameters too.
How much of that time is network travel?
What are the configuration settings for the archiving portion of pgBackRest?
Any reason not to bump it up to 1GB? Or is that overkill?
/Colin
On Wed, 17 Dec 2025 at 16:25, Laurenz Albe <[email protected]
<mailto:[email protected]>> wrote:
On Wed, 2025-12-17 at 16:13 +0100, Colin 't Hart wrote:
> I see very little advice on tuning WAL segment size.
>
> One of my clients has a few datawarehouses at around 8 - 16 TB
>
> On one of the nodes there are approx 15000 WAL segments of 16MB
each, totalling
> approx 230GB. The archiver is archiving approx one per second, so
approx 4 hours to clear.
>
> Would we gain anything by bumping the WAL segment size?
Very likely yes, if the problem is the overhead of starting the
archive_command.
Another thing that can slow down archiving is if you compress these
segments
too aggressively.
Yours,
Laurenz Albe
--
Adrian Klaver
[email protected]
