Re: set failover=true on existing logical replication slot PG18

> On Jun 19, 2026, at 9:24 AM, Scot Kreienkamp <Scot(dot)Kreienkamp(at)la-z-boy(dot)com> wrote:
>
> Hello list,
>
> I am trying to make use of the synchronized logical replication slots on PG18. I have all the requirements met, and if I create a logical replication slot manually with failover=true it is replicated to the second node. Unfortunately I have two connections that create their own logical replication slots with failover false. AWS DMS is one for example, but both have the same problem. Is there any way to change the failover parameter on an existing logical replication slot from false to true? Or set it so that all logical replications slots are synchronized so that they don’t have to be individually created or altered for replication=true? Or force them all to true? Any other ideas?
>
> Thanks!
>

I had the same problem recently with our Confluent-generated replication slots. I didn’t think there was but I just found this in the docs:

ALTER_REPLICATION_SLOT slot_name ( option [, ...] )
Change the definition of a replication slot. See Section 26.2.6 for more about replication slots. This command is currently only supported for logical replication slots.

slot_name
The name of the slot to alter. Must be a valid replication slot name (see Section 26.2.6.1).

The following option is supported:

FAILOVER [ boolean ]
If true, the slot is enabled to be synced to the standbys so that logical replication can be resumed after failover.

https://www.postgresql.org/docs/17/protocol-replication.html
53.4. Streaming Replication Protocol
postgresql.org