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

Dear Peter,

Thank you for reviewing! New patch is available in [1].

> 1.
>         Configure the servers for log shipping.  (You do not need to run
>         pg_backup_start() and
> pg_backup_stop()
>         or take a file system backup as the standbys are still synchronized
> -       with the primary.)  Replication slots are not copied and must
> -       be recreated.
> +       with the primary.) Only logical slots on the primary are copied to the
> +       new standby, and other other slots on the old standby must be recreated
> +       as they are not copied.
>        
> 
> IMO this text still needs some minor changes like shown below, Anyway,
> there is a typo: /other other/
> 
> SUGGESTION
> 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.
>

Fixed.

> ======
> src/bin/pg_upgrade/server.c
> 
> 2.
> + *
> + * Use max_slot_wal_keep_size as -1 to prevent the WAL removal by the
> + * checkpointer process.  If WALs required by logical replication slots are
> + * removed, the slots are unusable.  The setting ensures that such WAL
> + * records have remained so that invalidation of slots would be avoided
> + * during the upgrade.
> 
> The comment already explained the reason for the setting is to prevent
> removing the needed WAL records, so I felt there is no need for the
> last sentence to repeat the same information.
> 
> BEFORE
> The setting ensures that such WAL records have remained so that
> invalidation of slots would be avoided during the upgrade.
> 
> SUGGESTION
> This setting prevents the invalidation of slots during the upgrade.

Fixed.

[1]: https://www.postgresql.org/message-id/TYAPR01MB5866D63A6460059DC661BF62F5F6A%40TYAPR01MB5866.jpnprd01.prod.outlook.com

Best Regards,
Hayato Kuroda
FUJITSU LIMITED