Re: add checkpoint stats of snapshot and mapping files of pg_logical dir

On Wed, Mar 23, 2022 at 10:16 AM Bharath Rupireddy
<bharath(dot)rupireddyforpostgres(at)gmail(dot)com> wrote:
>
> On Tue, Mar 22, 2022 at 8:12 PM Andres Freund <andres(at)anarazel(dot)de> wrote:
> > > Do you mean like this?
> > > ereport(LOG,
> > > /* translator: the placeholders show checkpoint options */
> > > (errmsg("%s starting:%s%s%s%s%s%s%s%s",
> > > restartpoint ? _("restartpoint") : _("checkpoint"),
> > > (flags & CHECKPOINT_IS_SHUTDOWN) ? " shutdown" : "",
> > > (flags & CHECKPOINT_END_OF_RECOVERY) ? "
> > > end-of-recovery" : "",
> > > (flags & CHECKPOINT_IMMEDIATE) ? " immediate" : "",
> > > (flags & CHECKPOINT_FORCE) ? " force" : "",
> > > (flags & CHECKPOINT_WAIT) ? " wait" : "",
> > > (flags & CHECKPOINT_CAUSE_XLOG) ? " wal" : "",
> > > (flags & CHECKPOINT_CAUSE_TIME) ? " time" : "",
> > > (flags & CHECKPOINT_FLUSH_ALL) ? " flush-all" : "")));
> >
> > Yes.
>
> Done that way, see
> v7-0001-Deduplicate-checkpoint-restartpoint-starting-comp.patch.
>
> > > I think the reason in this case might be that some flag names with hyphens
> > > and spaces before words may not have the right/matching words in all
> > > languages. What happens if we choose to translate/not translate the entire
> > > message?
> >
> > If individual words aren't translated the "original" word would be used.
>
> Interestingly, the translated message for "checkpoint/restart
> complete" is empty. Maybe because it has untranslatable strings?
>
> #: access/transam/xlog.c:8752
> #, c-format
> msgid "restartpoint complete: wrote %d buffers (%.1f%%); %d WAL
> file(s) added, %d removed, %d recycled; write=%ld.%03d s,
> sync=%ld.%03d s, total=%ld.%03d s; sync files=%d, longest=%ld.%03d s,
> average=%ld.%03d s; distance=%d kB, estimate=%d kB"
> msgstr ""
>
> > > > Both seem still very long. I still am doubtful this level of detail is
> > > > appropriate. Seems more like a thing for a tracepoint or such. How about just
> > > > printing the time for the logical decoding operations in aggregate, without
> > > > breaking down into files, adding LSNs etc?
> > >
> > > The distinction that the patch makes right now is for snapshot and
> > > rewrite mapping files and it makes sense to have them separately.
> >
> > -1. The line also needs to be readable...
>
> IMHO, that's subjective. Even now, the existing
> "checkpoint/restartpoint complete" message has a good amount of info
> which makes it unreadable for some.
>
> The number of logical decoding files(snapshot and mapping) the
> checkpoint processed is a good metric to have in server logs along
> with the time it took for removing/syncing them. Thoughts?

Realized that the CF bot is applying patches in the alphabetical order
(I've sent out both v7 patches as v7-0001). Attaching v8 patch-set
with v8-0001 and v8-0002 names. Apart from this, no change in v8.

Regards,
Bharath Rupireddy.