I'm trying to understand if with v14 I will be able to connect Debezium to a "slave" node and not to the "master" in order to read the WAL but can't figure it out. Can someone help me with this?

I was just yesterday talking to someone about this; they mentioned that Patroni leverages some way for setting up replication slots on replicas [1]. Haven't tried my self yet, but seems worth exploring.

Something I'd like to dive into within Debezium is usage of the pg_tm_aux extension, which supposedly allows to set up replication slots "in the past", so you could use this to have seamless failover to replicas without missing any events. In any case, this entire area is of high importance for us and we're keeping an eye on any improvements closely, so I hope it will be sorted out sooner or later.

[1] https://twitter.com/cyberdemn/status/1443130986116624388 [2] https://github.com/x4m/pg_tm_aux

That extension is not safe / correct afaict.

Unfortunately that didn't make it into 14, there were too many rough edges to file off.

Yeah, I should have used "primary"/"replica", I agree. Somehow this words did not came to my mind. Thanks

Both are valid. Master/slave is an older way of describing how the two are related, but most DBMSes used this terminology up until recently.