Re: Would-be standby-node phoning home every 5 seconds. Why?

Errors disappeared after -- on node b -- I deleted $PGDATA/standby.signal
(makes sense) and primary_conninfo from postgresql.auto.conf, then
restarted the instance.

On Tue, Dec 19, 2023 at 11:14 AM Ron Johnson <ronljohnsonjr(at)gmail(dot)com>
wrote:

> wal_level = minimal.
>
> On Tue, Dec 19, 2023 at 11:09 AM SOzcn <selahattinozcnma(at)gmail(dot)com> wrote:
>
>> Hmm, It seems like NodeB is attempting to initialize replication despite
>> the termination and dropping of the replication slot. The error message
>> suggests that it's trying to establish a standby connection but
>> encountering a limitation regarding max_wal_senders, which is currently set
>> to 0.
>>
>> Could you restart your NodeB to check this? If It does not work there are
>> also some connection strings from applications.
>>
>> Also is your wal_level is replica in the Primary?
>>
>> Ron Johnson <ronljohnsonjr(at)gmail(dot)com>, 19 Ara 2023 Sal, 18:26 tarihinde
>> şunu yazdı:
>>
>>> max_wal_senders is currently 0. That's why it's complaining.
>>>
>>> On Tue, Dec 19, 2023 at 9:57 AM SOzcn <selahattinozcnma(at)gmail(dot)com>
>>> wrote:
>>>
>>>> Hello Ron, Can you check your "max_wal_senders" parameter value?
>>>> This is must come from the "max_wal_senders" parameter, if you set this
>>>> as 5 seconds it's going to check this for each 5 second.
>>>>
>>>> If you want to disable this, parameter value must be 0.
>>>>
>>>> Have a nice day!
>>>>
>>>> Ron Johnson <ronljohnsonjr(at)gmail(dot)com>, 19 Ara 2023 Sal, 17:08
>>>> tarihinde şunu yazdı:
>>>>
>>>>> PG 14.10
>>>>>
>>>>> I had initiated streaming replication on a pair of new instances from
>>>>> Node A to Node B, and then stopped it via:
>>>>> SELECT pg_terminate_backend(<wallreceiver pid>);
>>>>> SELECT pg_drop_replication_slot(<slot name>);
>>>>>
>>>>> That seemed to work, since Node A isn't replicating anymore:
>>>>>
>>>>> postgres=# SELECT * from pg_replication_slots;
>>>>> (0 rows)
>>>>>
>>>>> postgres=#
>>>>> postgres=# SELECT * from pg_stat_replication;
>>>>> (0 rows)
>>>>>
>>>>> Node B, unsurprisingly, doesn't have anything in pg_stat_wal_receiver.
>>>>> $ psql --host=NodeB -xc "SELECT * FROM pg_stat_wal_receiver;"
>>>>> (0 rows)
>>>>>
>>>>> And yet, Node B tries to initialize replication every 5 seconds. An
>>>>> excerpt from the log file:
>>>>> 2023-12-19 08:53:52.778 EST NodeB replicator 202014 initializing
>>>>> 53300 FATAL: 53300: number of requested standby connections exceeds
>>>>> max_wal_senders (currently 0)
>>>>> 2023-12-19 08:53:52.778 EST NodeB replicator 202014 initializing
>>>>> 53300 LOCATION: InitProcess, proc.c:358
>>>>>
>>>>>