Re: reducing isolation tests runtime

Tom Lane wrote:
> Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> writes:
> > On the subject of test total time, we could paralelize isolation tests.
> > Right now "make check" in src/test/isolation takes 1:16 on my machine.
> > Test "timeouts" takes full 40s of that, with nothing running in parallel
> > -- the machine is completely idle.
>
> BTW, one small issue there is that the reason the timeouts test is so
> slow is that we have to use multi-second timeouts to be sure slower
> buildfarm critters (eg valgrind animals) will get the expected results.
> So I'm worried that if the machine isn't otherwise idle, we will get
> random failures.

I think we could solve this by putting in the same parallel group only
slow tests that mostly sleeps, ie. nothing that would monopolize CPU for
long enough to cause a problem. Concretely:

test: timeouts tuplelock-update deadlock-hard deadlock-soft-2

all of these tests have lots of sleeps and don't go through a lot of
data. (Compared to the previous patch, I removed alter-table-1, which
uses a thousand tuples, and multiple-row-versions, which uses 100k; also
removed receipt-report which uses a large number of permutations.)

Timings:
timeouts 40.3s
tuplelock-update 10.5s
deadlock-hard 10.9s
deadlock-soft-2 5.4s

alter-table-1 takes 1.5s, receipt-report 1.2s and there's nothing else
that takes above 1s, so I think this is good enough -- we can still have
the whole thing run in ~45 seconds without the hazard you describe.

--
Álvaro Herrera https://www.2ndQuadrant.com/
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