On 2024-07-21 Su 4:08 PM, Alexander Lakhin wrote:
Hello,
21.07.2024 20:34, Tom Lane wrote:
Andrew Dunstan <and...@dunslane.net> writes:
I noticed this when working on the PostgreSQL::Test::Session project I
have in hand. All the tests pass except occasionally the xid_wraparound
tests fail. It's not always the same test script that fails either. I
tried everything but couldn't make the failure stop. So then I switched
out my patch so it's running on plain master and set things running
in a
loop. Lo and behold it can be relied on to fail after only a few
iterations.
I have been noticing xid_wraparound failures in the buildfarm too.
They seemed quite infrequent, but it wasn't till just now that
I realized that xid_wraparound is not run by default. (You have to
put "xid_wraparound" in PG_TEST_EXTRA to enable it.) AFAICS the
only buildfarm animals that have enabled it are dodo and perentie.
dodo is failing this test fairly often:
https://buildfarm.postgresql.org/cgi-bin/show_history.pl?nm=dodo&br=HEAD
I think this failure is counted at [1]. Please look at the linked message
[2], where I described what makes the test fail.
[1]
https://wiki.postgresql.org/wiki/Known_Buildfarm_Test_Failures#001_emergency_vacuum.pl_fails_to_wait_for_datfrozenxid_advancing
[2]
https://www.postgresql.org/message-id/5811175c-1a31-4869-032f-7af5e3e45...@gmail.com
It's sad nothing has happened abut this for 2 months.
There's no point in having unreliable tests. What's not 100% clear to me
is whether this failure indicates a badly formulated test or the test is
correct and has identified an underlying bug.
Regarding the point in [2] about the test being run twice in buildfarm
clients, I think we should mark the module as NO_INSTALLCHECK in the
Makefile.
cheers
andrew
--
Andrew Dunstan
EDB: https://www.enterprisedb.com
