Re: Add wait events for server logging destination writes

Hi Seongjun,

On Wed, Oct 28, 2026 at 10:00 PM 신성준 <shinsj4653(at)gmail(dot)com> wrote:
> v9 keeps an outer wait event across a log write by using
> pgstat_report_wait_start_nested() / pgstat_report_wait_end_nested()
> at the new logging sites. That was the open point from Nik's last
> review.
>
> What would help most now:
> - Nik, a rerun of your harness against v9 when you have a free
> moment. No hurry.

My AI harness tested v9 on master at b6178c942ea7, cassert build. The
outer event survives the log write now. Sampled after ereport(LOG)
returned, inside the extension's region, v9 shows

active | Extension | HarnessOuterWait

for stderr with logging_collector off and on, csvlog, jsonlog, all
three together, and syslog. v8 shows an empty wait_event_type and
wait_event in the same runs, so the check can tell them apart. The
core regression suite passes with v9.

I also read the wrapped sites. They wrap only leaf OS calls (write(),
openlog(), syslog(), and the Windows calls in 0002), and nothing in
between can ereport, so I see no path that leaves start without end.

No new findings. I did not test Windows or the macro alternative
Henson described.

From the tester's side I consider v9 ready.

Thanks,
Nik