Re: Implement waiting for wal lsn replay: reloaded - Mailing list pgsql-hackers

Hi Alexander,

On Sat, Jan 3, 2026 at 6:54 AM Alexander Korotkov <aekorotkov@gmail.com> wrote:
>
> Hi, Xuneng!
>
> On Fri, Jan 2, 2026 at 11:17 AM Xuneng Zhou <xunengzhou@gmail.com> wrote:
> > On Fri, Jan 2, 2026 at 7:42 AM Alexander Korotkov <aekorotkov@gmail.com> wrote:
> > >
> > > On Thu, Jan 1, 2026 at 7:16 PM Álvaro Herrera <alvherre@kurilemu.de> wrote:
> > > > In 0002 you have this kind of thing:
> > > >
> > > > >                               ereport(ERROR,
> > > > >                                               errcode(ERRCODE_QUERY_CANCELED),
> > > > > -                                             errmsg("timed out while waiting for target LSN %X/%08X to be
replayed;current replay LSN %X/%08X", 
> > > > > +                                             errmsg("timed out while waiting for target LSN %X/%08X to be
%s;current %s LSN %X/%08X", 
> > > > >                                                          LSN_FORMAT_ARGS(lsn),
> > > > > -                                                        LSN_FORMAT_ARGS(GetXLogReplayRecPtr(NULL))));
> > > > > +                                                        desc->verb,
> > > > > +                                                        desc->noun,
> > > > > +                                                        LSN_FORMAT_ARGS(currentLSN)));
> > > > > +                     }
> > > >
> > > >
> > > > I'm afraid this technique doesn't work, for translatability reasons.
> > > > Your whole design of having a struct with ->verb and ->noun is not
> > > > workable (which is a pity, but you can't really fight this.) You need to
> > > > spell out the whole messages for each case, something like
> > > >
> > > > if (lsntype == replay)
> > > >    ereport(ERROR,
> > > >            errcode(ERRCODE_QUERY_CANCELED),
> > > >            errmsg("timed out while waiting for target LSN %X/%08X to be replayed; current standby_replay LSN
%X/%08X",
> > > > else if (lsntype == flush)
> > > >     ereport( ... )
> > > >
> > > > and so on.  This means four separate messages for translation for each
> > > > message your patch is adding, which is IMO the correct approach.
> > >
> > > +1
> > > Thank you for catching this, Alvaro.  Yes, I think we need to get rid
> > > of WaitLSNTypeDesc.  It's nice idea, but we support too many languages
> > > to have something like this.
> > >
> >
> > Thanks for pointing this out. This approach doesn’t scale to multiple
> > languages. While switch statements are more verbose, the extra clarity
> > is justified to preserve proper internationalization. Please check the
> > updated v12.
>
> I've corrected the patchset.  Mostly changed just comments, formatting
> etc.  I'm going to push it if no objections.
>

Thanks for updating the patchset. LGTM.

--
Best,
Xuneng