Re: pgbench logging broken by time logic changes

On Fri, Jul 9, 2021 at 5:14 PM Fabien COELHO <coelho@cri.ensmp.fr> wrote:
> Works for me: patch applies, global and local check ok. I'm fine with it.

I hoped we were done here but I realised that your check for 1-3 log
lines will not survive the harsh environment of the build farm.
Adding sleep(2) before the final doLog() confirms that.  I had two
ideas:

1.  Give up and expect 1-180 lines.  (180s is the current timeout
tolerance used elsewhere to deal with
swamped/valgrind/swapping/microsd computers, after a few rounds of
inflation, so if you need an arbitrary large number to avoid buildfarm
measles that's my suggestion....)
2.  Change doLog() to give up after end_time.  But then I think you'd
need to make it 0-3 :-(

I think the logging could be tightened up to work the way you expected
in future work, though.  Perhaps we could change all logging to work
with transaction start time instead of log-writing time, which doLog()
should receive.  If you never start a transaction after end_time, then
there can never be an aggregate that begins after that, and the whole
thing becomes more deterministic.  That kind of alignment of aggregate
timing with whole-run timing could also get rid of those partial
aggregates completely.  But that's an idea for 15.

So I think we should do 1 for now.  Objections or better ideas?