Re: [PoC] pg_upgrade: allow to upgrade publisher node

On Thu, Aug 17, 2023 at 3:48 PM Hayato Kuroda (Fujitsu)
<kuroda.hayato@fujitsu.com> wrote:
>
> > > * Added checks for output plugin libraries. pg_upgrade ensures that plugins
> > >   referred by old slots were installed to the new executable directory.
> > >
> >
> > I think this is a good idea but did you test it with out-of-core
> > plugins, if so, can you please share the results? Also, let's update
> > this information in docs as well.
>
> I have not used other plugins, but forcibly renamed the shared object file.
> I would test by plugins like wal2json[1] if more cases are needed.
>
> 1. created logical replication slots on old node
>   SELECT * FROM pg_create_logical_replication_slot('test', 'test_decoding')
> 2. stopped the old nde
> 3. forcibly renamed the so file. I used following script:
>   sudo mv /path/to/test_decoding.so /path/to//test\"_decoding.so
> 4. executed pg_upgrade and failed. Outputs what I got were:
>
> ```
> Checking for presence of required libraries                 fatal
>

Your test sounds reasonable but there is no harm in testing wal2json
or some other plugin just to mimic the actual production scenario.
Additionally, it would give us better coverage for the patch by
testing out-of-core plugins for some other tests as well.

--
With Regards,
Amit Kapila.