On 28.11.21 07:52, Bharath Rupireddy wrote:
1) Instead of a new LIST_SLOT command, can't we use READ_REPLICATION_SLOT (slight modifications needs to be done to make it support logical replication slots and to get more information from the subscriber).
I looked at that but didn't see an obvious way to consolidate them. This is something we could look at again later.
2) How frequently the new bg worker is going to sync the slot info? How can it ensure that the latest information exists say when the subscriber is down/crashed before it picks up the latest slot information?
The interval is currently hardcoded, but could be a configuration setting. In the v2 patch, there is a new setting that orders physical replication before logical so that the logical subscribers cannot get ahead of the physical standby.
3) Instead of the subscriber pulling the slot info, why can't the publisher (via the walsender or a new bg worker maybe?) push the latest slot info? I'm not sure we want to add more functionality to the walsender, if yes, isn't it going to be much simpler?
This sounds like the failover slot feature, which was rejected.
