RE: Assertion failure in SnapBuildInitialSnapshot()

Hi,


On Tuesday, November 15, 2022 10:26 AM Andres Freund <andres@anarazel.de> wrote:
> On 2022-11-10 16:04:40 +0530, Amit Kapila wrote:
> > I don't have any good ideas on how to proceed with this. Any thoughts
> > on this would be helpful?
> 
> One thing worth doing might be to convert the assertion path into an elog(),
> mentioning both xids (or add a framework for things like AssertLT(), but that
> seems hard). With the concrete values we could make a better guess at
> what's going wrong.
> 
> It'd probably not hurt to just perform this check independent of
> USE_ASSERT_CHECKING - compared to the cost of creating a slot it's
> neglegible.
> 
> That'll obviously only help us whenever we re-encounter the issue, which will
> likely be a while...
> 
> 
> Have you tried reproducing the issue by running the test in a loop?
Just FYI, I've tried to reproduce this failure in a loop,
but I couldn't hit the same assertion failure.


I extracted the #16643 of 100_bugs.pl only and
executed the tests more than 500 times.


My env and test was done in rhel7.9 and gcc 4.8 with configure option of
--enable-cassert --enable-debug --enable-tap-tests --with-icu CFLAGS=-O0 and prefix.



Best Regards,
	Takamichi Osumi