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

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
>>>>
>>>>