Re: Proposal: GUC to control starting/stopping logical subscription workers

Hi,

On Tue, Sep 9, 2025 at 1:16 PM SATYANARAYANA NARLAPURAM
<satyanarlapuram(at)gmail(dot)com> wrote:
>
>> If I understand correctly, the end effect is similar to disabling all
>> subscriptions. Why not just add ALTER SUBSCRIPTION ... DISABLE for all
>> subscriptions in the failover work flow? Migration of logical
>> replication slots docs says so -
>> https://www.postgresql.org/docs/18/logical-replication-upgrade.html.
>
> The scenarios I am talking in this case are no major version upgrade, but PITR and Standby promotion cases.
> Server is in read only mode (catalog cannot be updated) before promotion and subscriptions cannot be disabled.

Thanks for clarifying. AFAICS, failover slots won't have this issue.
All the replication connections start to fail during standby's
promotion (StartLogicalReplication->CreateDecodingContext->errmsg("cannot
use replication slot \"%s\" for logical decoding") and replication
from publisher resumes automatically after promotion and slots are
fully synced.

--
Bharath Rupireddy
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com