Looks like guaibasaurus had a autovacuum running during the
controller_print_speculative_locks step (just added in
43e0841970). Which does indeed seem quite possible.
Avoid the problem by only looking for the backends participating in
the test.
Previously, the speculative insert tests did not cover the case when a
tuple t is inserted into a table with a unique index on a column but
before it can insert into the index, a concurrent transaction has
inserted a conflicting value into the index and the insertion of tuple t
must be aborted.
The basic permutation is one session successfully inserts into the table
and an associated unique index while a concurrent session successfully
inserts into the table but discovers a conflict before inserting into
the index and must abort the insertion.
Several variants on this include:
- swap which session is successful
- first session insert transaction does not commit, so second session
must wait on a transaction lock
- first session insert does not "complete", so second session must wait
on a speculative insertion lock
Also, refactor the existing TOAST table upsert test to be in the same
spec and reuse the steps.
Author: Melanie Plageman, Ashwin Agrawal, Andres Freund
Reviewed-by: Andres Freund, Taylor Vesely
Discussion: https://postgr.es/m/CAAKRu_ZRmxy_OEryfY3G8Zp01ouhgw59_-_Cm8n7LzRH5BAvng@mail.gmail.com
If a test sends a notice just before blocking, it's possible on
slow machines for isolationtester to detect the blocked state before
it's consumed the notice. (For this to happen, the notice would have
to arrive after isolationtester has waited for data for 10ms, so on
fast/lightly-loaded machines it's hard to reproduce the failure.)
But, if we have seen the backend as blocked, it's certainly already
sent any notices it's going to send. Therefore, one more round of
PQconsumeInput and PQisBusy should be enough to collect and process
any such notices.
This appears to explain the instability noted in commit ebd499282, so undo
the hack therein to not print notices from insert-conflict-specconflict.
Patch by me, diagnosis by Andres Freund.
Discussion: https://postgr.es/m/14616.1564251339@sss.pgh.pa.us
This path previously was not reliably covered. There was some
heuristic coverage via insert-conflict-toast.spec, but that test is
not deterministic, and only tested for a somewhat specific bug.
Backpatch, as this is a complicated and otherwise untested code
path. Unfortunately 9.5 cannot handle two waiting sessions, and thus
cannot execute this test.
Triggered by a conversion with Melanie Plageman.
Author: Andres Freund
Discussion: https://postgr.es/m/CAAKRu_a7hbyrk=wveHYhr4LbcRnRCG=yPUVoQYB9YO1CdUBE9Q@mail.gmail.com
Backpatch: 9.5-
Andres Freund
Tom Lane