Package "postgresql-12-pg-failover-slots"

High-availability support for PostgreSQL logical replication
This extension is for anyone with Logical Replication Slots on
Postgres databases that are also part of a Physical Streaming
Replication architecture.

Since logical replication slots are only maintained on the primary
node, downstream subscribers don't receive any new changes from a
newly promoted primary until the slot is created, which is unsafe
because the information that includes which data a subscriber has
confirmed receiving and which log data still needs to be retained for
the subscriber will have been lost, resulting in an unknown gap in
data changes. PG Failover Slots makes logical replication slots
usable across a physical failover using the following features:

- Copies any missing replication slots from the primary to the
standby
- Removes any slots from the standby that aren't found on the primary
- Periodically synchronizes the position of slots on the standby
based on the primary
- Ensures that selected standbys receive data before any of the
logical slot walsenders can send data to consumers