Horton

Re: Improving isolationtester's data output

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@anarazel.de>
Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>, pgsql-hackers@lists.postgresql.org
Date: 2021-06-16T01:43:31Z
Lists: pgsql-hackers 
Andres Freund <andres@anarazel.de> writes:
> On 2021-06-15 19:26:25 -0400, Tom Lane wrote:
>> Going forward it wouldn't be a problem, but back-patching isolation
>> test cases might find it annoying.  On the other hand, my nearby
>> patch to improve isolation test stability is already going to create
>> issues of that sort.  (Unless, dare I say it, we back-patch that.)

> It might be worth to back-patch - aren't there some back branch cases of
> test instability? And perhaps more importantly, I'm sure we'll encounter
> cases of writing new isolation tests in the course of fixing bugs that
> we'd want to backpatch that are hard to make reliable without the new
> features?

Yeah, there absolutely is a case to back-patch things like this.  Whether
it's a strong enough case, I dunno.  I'm probably too close to the patch
to have an unbiased opinion about that.

However, a quick look through the commit history finds several places
where we complained about not being able to back-patch isolation tests to
before 9.6 because we hadn't back-patched that version's isolationtester
improvements.  I found 6b802cfc7, 790026972, c88411995, 8b21b416e without
looking too hard.  So that history certainly suggests that not
back-patching such test infrastructure is the Wrong Thing.

(And yeah, the failures we complained of in the other thread are
certainly there in the back branches.  I think the only reason there
seem to be fewer is that the back branches see fewer test runs.)

			regards, tom lane

Commits

  1. Improve display of query results in isolation tests.

  2. Detect unused steps in isolation specs and do some cleanup

  3. Remove dry-run mode from isolationtester