On Wed, Jan 3, 2024 at 12:09 PM vignesh C <vignesh21@gmail.com> wrote:
>
> On Wed, 1 Nov 2023 at 19:28, Ashutosh Bapat
> <ashutosh.bapat.oss@gmail.com> wrote:
> >
> > At this stage the standby would have various replication objects like
> > publications, subscriptions, origins inherited from the upstream
> > server and possibly very much active. With failover slots, it might
> > inherit replication slots. Is it intended that the new subscriber also
> > acts as publisher for source's subscribers OR that the new subscriber
> > should subscribe to the upstreams of the source? Some use cases like
> > logical standby might require that but a multi-master multi-node setup
> > may not. The behaviour should be user configurable.
>
> How about we do like this:
> a) Starting the server in binary upgrade mode(so that the existing
> subscriptions will not try to connect to the publishers)
>
Can't we simply do it by starting the server with
max_logical_replication_workers = 0 or is there some other need to
start in binary upgrade mode?
b) Disable
> the subscriptions
>
Why not simply drop the subscriptions?
c) Drop the replication slots d) Drop the
> publications
>
I am not so sure about dropping publications because, unlike
subscriptions which can start to pull the data, there is no harm with
publications. Similar to publications there could be some user-defined
functions or other other objects which may not be required once the
standby replica is converted to subscriber. I guess we need to leave
those to the user.
e) Then restart the server in normal(non-upgrade) mode.
> f) The rest of pg_subscriber work like
> create_all_logical_replication_slots, create_subscription,
> set_replication_progress, enable_subscription, etc
> This will be done by default. There will be an option
> --clean-logical-replication-info provided to allow DBA not to clean
> the objects if DBA does not want to remove these objects.
>
I agree that some kind of switch to control this action would be useful.
--
With Regards,
Amit Kapila.