Thread

Re: Excessive LOG messages from replication slot sync worker

Japin Li <japinli@hotmail.com> — 2025-08-12T11:13:51Z

On Tue, Aug 12, 2025 at 07:58:25PM +0900, Fujii Masao wrote:
> On Tue, Aug 12, 2025 at 7:14 PM Fujii Masao <masao.fujii@gmail.com> wrote:
> >
> > On Tue, Aug 12, 2025 at 6:25 PM Japin Li <japinli@hotmail.com> wrote:
> > > I believe that the format %X-%X also works with sscanf(). However, to maintain
> > > consistency, the format for sscanf() has been updated as well.
> >
> > Yes.
> > Thanks for the patch!
> 
> With the patch, the excessive LOG messages from the replication slot sync
> worker are gone. However, it still logged periodically, about two messages
> every 30 seconds, for example:
> 
> 2025-08-12 19:49:03.288 JST [sby][slotsync worker] LOG:  starting
> logical decoding for slot "mysub"
> 2025-08-12 19:49:03.288 JST [sby][slotsync worker] DETAIL:  Streaming
> transactions committing after 0/0FAD3940, reading WAL from 0/0D4C9CE8.
> 2025-08-12 19:49:03.289 JST [sby][slotsync worker] LOG:  logical
> decoding found consistent point at 0/0D4C9CE8
> 2025-08-12 19:49:03.289 JST [sby][slotsync worker] DETAIL:  Logical
> decoding will begin using saved snapshot.
> 2025-08-12 19:49:46.048 JST [sby][slotsync worker] LOG:  starting
> logical decoding for slot "mysub"
> 2025-08-12 19:49:46.048 JST [sby][slotsync worker] DETAIL:  Streaming
> transactions committing after 0/10A60230, reading WAL from 0/0FAEE120.
> 2025-08-12 19:49:46.049 JST [sby][slotsync worker] LOG:  logical
> decoding found consistent point at 0/0FAEE120
> 2025-08-12 19:49:46.049 JST [sby][slotsync worker] DETAIL:  Logical
> decoding will begin using saved snapshot.
> 
>
I think this is not related to the logical snapshot name.

> 
> I'm not sure these messages are useful for end users, and LOG might not be
> the right level. They seem more like debug information, so should we consider
> changing them to DEBUG, even with the proposed patch applied?

+1.

-- 
Best regards,
Japin Li
ChengDu WenWu Information Technology Co., LTD.