Re: Can we automatically add elapsed times to tap test log?

Andres Freund <andres@anarazel.de>

From: Andres Freund <andres@anarazel.de>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Andrew Dunstan <andrew@dunslane.net>, Nathan Bossart <nathandbossart@gmail.com>, pgsql-hackers@postgresql.org
Date: 2022-04-07T21:38:35Z
Lists: pgsql-hackers
Hi,

On 2022-04-07 17:21:09 -0400, Tom Lane wrote:
> Andrew Dunstan <andrew@dunslane.net> writes:
> > On 4/2/22 06:57, Andrew Dunstan wrote:
> >> Here's a version that actually works. It produces traces that look like
> >> this:
> >> andrew@emma:pg_upgrade $ grep '([0-9]*s)'
> >> tmp_check/log/regress_log_002_pg_upgrade
> >> [21:55:06](63s) ok 1 - dump before running pg_upgrade
> >> [21:55:22](79s) ok 2 - run of pg_upgrade for new instance
> >> [21:55:27](84s) ok 3 - old and new dumps match after pg_upgrade
> >> [21:55:27](84s) 1..3
> 
> > I know there's a lot going on, but are people interested in this? It's a
> > pretty small patch to produce something that seems quite useful.

It's been 0 days since I last wanted this.


> I too think that the elapsed time is useful.  I'm less convinced
> that the time-of-day marker is useful.

I think it'd be quite useful if it had more precision - it's a pita to
correlate regress_log_* output with server logs.


> It also seems kind of odd that the elapsed time accumulates rather
> than being reset for each line.  As it stands one would be doing a lot
> of mental subtractions rather than being able to see directly how long
> each step takes.  I suppose that on fast machines where each step is
> under one second, accumulation would be more useful than printing a
> lot of zeroes --- but on the other hand, those aren't the cases where
> you're going to be terribly concerned about the runtime.

I like both - if you want to find where the slowdown among a lot of log lines
is, it's easier to look at the time accumulated elapsed time. If you actually
want to see how long individual things take, non-accumulated is more useful.

I've printed both in the past...

Any chance we could print higher res time?

Greetings,

Andres Freund



Commits

  1. Add timestamp and elapsed time decorations to TAP test logs