On 2021-Mar-31, Tom Lane wrote: > I think this is a timing problem that's triggered (on some machines) > by force_parallel_mode = regress. Looking at spurfowl's latest > failure of this type, the postmaster log shows > > 2021-03-31 14:34:54.982 EDT [18233:15] 001_libpq_pipeline.pl LOG: execute > <unnamed>: SELECT 1.0/g FROM generate_series(3, -1, -1) g > 2021-03-31 14:34:54.992 EDT [18234:1] ERROR: division by zero > 2021-03-31 14:34:54.992 EDT [18234:2] STATEMENT: SELECT 1.0/g FROM > generate_series(3, -1, -1) g > 2021-03-31 14:34:54.993 EDT [18233:16] 001_libpq_pipeline.pl ERROR: division > by zero > 2021-03-31 14:34:54.993 EDT [18233:17] 001_libpq_pipeline.pl STATEMENT: > SELECT 1.0/g FROM generate_series(3, -1, -1) g > 2021-03-31 14:34:54.995 EDT [18216:4] LOG: background worker "parallel > worker" (PID 18234) exited with exit code 1 > 2021-03-31 14:34:54.995 EDT [18233:18] 001_libpq_pipeline.pl LOG: could not > send data to client: Broken pipe > 2021-03-31 14:34:54.995 EDT [18233:19] 001_libpq_pipeline.pl FATAL: > connection to client lost > > We can see that the division by zero occurred in a parallel worker. > My theory is that in parallel mode, it's uncertain whether the > error will be reported before or after the "preceding" successful > output rows. So you need to disable parallelism to make this > test case stable.
Ooh, that makes sense, thanks. Added a SET in the program itself to set it to off. This is not the *only* issue though; at least animal drongo shows a completely different failure, where the last few tests don't even get to run, and the server log just has this: 2021-03-31 20:20:14.460 UTC [178364:4] 001_libpq_pipeline.pl LOG: disconnection: session time: 0:00:00.469 user=pgrunner database=postgres host=127.0.0.1 port=52638 2021-03-31 20:20:14.681 UTC [178696:1] [unknown] LOG: connection received: host=127.0.0.1 port=52639 2021-03-31 20:20:14.687 UTC [178696:2] [unknown] LOG: connection authorized: user=pgrunner database=postgres application_name=001_libpq_pipeline.pl 2021-03-31 20:20:15.157 UTC [178696:3] 001_libpq_pipeline.pl LOG: could not receive data from client: An existing connection was forcibly closed by the remote host. I suppose the program is crashing for some reason. -- Álvaro Herrera Valdivia, Chile "Los dioses no protegen a los insensatos. Éstos reciben protección de otros insensatos mejor dotados" (Luis Wu, Mundo Anillo)
