Re: Log connection establishment timings

Thanks for taking a look!

On Mon, Jan 20, 2025 at 10:01 AM Bertrand Drouvot
<bertranddrouvot.pg@gmail.com> wrote:
>
> The patch needed a rebase due to 34486b6092e. I did it in v2 attached (it's
> a minor rebase due to the AmRegularBackendProcess() introduction in miscadmin.h).
>
> v2 could rely on AmRegularBackendProcess() instead of AmClientBackendProcess()
> but I kept it with AmClientBackendProcess() to reduce "my" changes as compared to
> v1.

Thanks for doing this! I have implemented your suggestion in attached v3.

> Regarding the TimestampTz vs instr_time choice, we have things like:
< -- snip -- >
> So with TimestampTz, we would:
>
> 1. return 0 if we moved the time backward
> 2. provide an inflated duration including the time jump (if the time move
> forward).
>
> But with instr_time (and on systems that support CLOCK_MONOTONIC) then
> pg_clock_gettime_ns() should not be affected by system time change IIUC.
>
> Though time changes are "rare", given the fact that those metrics could provide
> "inaccurate" measurements during that particular moment (time change) then it
> might be worth considering instr_time instead for this particular metric.

Great point. This all makes sense. I've switched to using instr_time in v3.

- Melanie