Re: Documentation to upgrade logical replication cluster

On Mon, 29 Jan 2024 at 06:34, Peter Smith <smithpb2250@gmail.com> wrote:
>
> Hi Vignesh,
>
> Here are some review comments for patch v4.
>
> These are cosmetic only; otherwise v4 LGTM.
>
> ======
> doc/src/sgml/ref/pgupgrade.sgml
>
> 1.
>         Configure the servers for log shipping.  (You do not need to run
>         <function>pg_backup_start()</function> and
> <function>pg_backup_stop()</function>
>         or take a file system backup as the standbys are still synchronized
> -       with the primary.)  Only logical slots on the primary are copied to the
> -       new standby, but other slots on the old standby are not copied so must
> -       be recreated manually.
> +       with the primary.)  If the old cluster is prior to 17.0, then no slots
> +       on the primary are copied to the new standby, so all the slots must be
> +       recreated manually. If the old cluster is 17.0 or later, then only
> +       logical slots on the primary are copied to the new standby, but other
> +       slots on the old standby are not copied so must be recreated manually.
>        </para>
>
> Perhaps the part from "If the old cluster is prior..." should be in a
> new paragraph.

Modified

> ======
> doc/src/sgml/logical-replication.sgml
>
> 2.
> +   <para>
> +    Setup the <link linkend="logical-replication-config-subscriber">
> +    subscriber configurations</link> in the new subscriber.
> +    <application>pg_upgrade</application> attempts to migrate subscription
> +    dependencies which includes the subscription's table information present in
> +    <link linkend="catalog-pg-subscription-rel">pg_subscription_rel</link>
> +    system catalog and also the subscription's replication origin. This allows
> +    logical replication on the new subscriber to continue from where the
> +    old subscriber was up to. Migration of subscription dependencies is only
> +    supported when the old cluster is version 17.0 or later. Subscription
> +    dependencies on clusters before version 17.0 will silently be ignored.
> +   </para>
>
> Perhaps the part from "pg_upgrade attempts..." should be in a new paragraph.

Modified

Thanks for the comments, the attached v5 version patch has the changes
for the same.

Regards,
Vignesh