Dear Shveta,
I resumed to review the patch. I will play more about it, but I can post some
cosmetic comments.
====
walsender.c
01. WalSndWaitForStandbyConfirmation
```
+ sleeptime = WalSndComputeSleeptime(GetCurrentTimestamp());
```
It works well, but I'm not sure whether we should use WalSndComputeSleeptime()
because the function won't be called by walsender.
02.WalSndWaitForStandbyConfirmation
```
+ ConditionVariableTimedSleep(&WalSndCtl->wal_confirm_rcv_cv, sleeptime,
+
WAIT_EVENT_WAL_SENDER_WAIT_FOR_STANDBY_CONFIRMATION)
```
Hmm, is it OK to use the same event as WalSndWaitForWal()? IIUC it should be
avoided.
03. WalSndShmemInit()
```
+
+ ConditionVariableInit(&WalSndCtl->wal_confirm_rcv_cv);
```
Unnecessary blank?
~~~~~
050_standby_failover_slots_sync.pl
04. General
My pgperltidy modified your test. Please check.
05.
```
# Create publication on the primary
```
Missing "a" before publication?
06.
```
$subscriber1->init(allows_streaming => 'logical');
...
$subscriber2->init(allows_streaming => 'logical');
```
IIUC, these settings are not needed.
07.
```
my $primary_insert_time = time();
```
The variable is not used.
08.
```
# Stop the standby associated with the specified physical replication slot so
# that the logical replication slot won't receive changes until the standby
# slot's restart_lsn is advanced or the slot is removed from the
# standby_slot_names list
```
Missing comma?
09.
```
$back_q->query_until(qr//,
"SELECT pg_logical_slot_get_changes('test_slot', NULL, NULL);\n");
```
Not sure, should we have to close the back_q connection?
10.
```
# Remove the standby from the standby_slot_names list and reload the
# configuration
$primary->adjust_conf('postgresql.conf', 'standby_slot_names', "''");
$primary->psql('postgres', "SELECT pg_reload_conf()");
```
a.
Missing comma?
b.
I counted and reload function in perl (e.g., `$primary->reload;`) is more often
to
be used. Do you have a reason to use pg_reload_conf()?
11.
```
# Now that the standby lsn has advanced, the primary must send the decoded
# changes to the subscription.
$publisher->wait_for_catchup('regress_mysub1');
```
Is the comment correct? I think primary sends data because the GUC is modified.
12.
```
# Put the standby back on the primary_slot_name for the rest of the tests
$primary->adjust_conf('postgresql.conf', 'standby_slot_names', 'sb1_slot');
$primary->restart();
```
Just to confirm - you used restart() here because we must ensure the GUC change
is
propagated to all backends, right?
~~~~~
wait_event_names.txt
13.
```
+WAL_SENDER_WAIT_FOR_STANDBY_CONFIRMATION "Waiting for the WAL to be
received by physical standby in WAL sender process."
```
But there is a possibility that backend processes may wait with the event,
right?
Best Regards,
Hayato Kuroda
FUJITSU LIMITED
