Re: [HACKERS] logical decoding of two-phase transactions

On Wed, Jul 14, 2021 at 11:52 AM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>
> On Mon, Jul 12, 2021 at 9:14 AM Peter Smith <smithpb2250(at)gmail(dot)com> wrote:
>
> Pushed.
>

As reported by Michael [1], there is one test failure related to this
commit. The failure is as below:

# Failed test 'transaction is prepared on subscriber'
# at t/021_twophase.pl line 324.
# got: '1'
# expected: '2'
# Looks like you failed 1 test of 24.
[12:14:02] t/021_twophase.pl ..................
Dubious, test returned 1 (wstat 256, 0x100)
Failed 1/24 subtests
[12:14:12] t/022_twophase_cascade.pl .......... ok 10542 ms ( 0.00
usr 0.00 sys + 2.03 cusr 0.61 csys = 2.64 CPU)
[12:14:31] t/100_bugs.pl ...................... ok 18550 ms ( 0.00
usr 0.00 sys + 3.85 cusr 1.36 csys = 5.21 CPU)
[12:14:31]

I think I know what's going wrong here. The corresponding test is:

# Now do a prepare on publisher and check that it IS replicated
$node_publisher->safe_psql('postgres', "
BEGIN;
INSERT INTO tab_copy VALUES (99);
PREPARE TRANSACTION 'mygid';");

$node_publisher->wait_for_catchup($appname_copy);

# Check that the transaction has been prepared on the subscriber,
there will be 2
# prepared transactions for the 2 subscriptions.
$result = $node_subscriber->safe_psql('postgres', "SELECT count(*)
FROM pg_prepared_xacts;");
is($result, qq(2), 'transaction is prepared on subscriber');

Here, the test is expecting 2 prepared transactions corresponding to
two subscriptions but it waits for just one subscription via
appname_copy. It should wait for the second subscription using
$appname as well.

What do you think?

[1] - https://www.postgresql.org/message-id/YQP02%2B5yLCIgmdJY%40paquier.xyz

--
With Regards,
Amit Kapila.