Re: POC: enable logical decoding when wal_level = 'replica' without a server restart

On Sun, Nov 9, 2025 at 8:51 PM Peter Smith <smithpb2250(at)gmail(dot)com> wrote:
>
> Hi Sawada-San.
>
> Some review comments for v24-0001.
>
> ======
> src/backend/replication/slot.c
>
> ReplicationSlotsDropDBSlots:
>
> 1.
> LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
> for (i = 0; i < max_replication_slots; i++)
> {
> ReplicationSlot *s;
> + bool invalidated;
> char *slotname;
> int active_pid;
>
> @@ -1462,11 +1494,22 @@ restart:
> if (!SlotIsLogical(s))
> continue;
>
> + SpinLockAcquire(&s->mutex);
> + invalidated = s->data.invalidated == RS_INVAL_NONE;
> + SpinLockRelease(&s->mutex);
> +
> + /*
> + * Count slots on other databases too so we can disable logical
> + * decoding only if no slots in the cluster.
> + */
> + if (invalidated)
> + n_valid_logicalslots++;
> +
>
> IMO it's misleading/backwards to have bool invalidated == true when
> the invalidated member is RS_INVAL_NONE.
>
> It's fine to rename the bool var as 'invalidated', but don't you also
> need to reverse the assignment to (s->data.invalidated !=
> RS_INVAL_NONE) instead of (s->data.invalidated == RS_INVAL_NONE)?

Thank you for the comment! I'll fix it in the next version patch.

Regards,

--
Masahiko Sawada
Amazon Web Services: https://aws.amazon.com