Logical replication requires several configuration options to be set.
   On the publisher side, wal_level must be set to
   logical, and max_replication_slots
   must be set to at least the number of subscriptions expected to connect,
   plus some reserve for table synchronization.  And
   max_wal_senders should be set to at least the same as
   max_replication_slots plus the number of physical
   replicas that are connected at the same time.
  
   The subscriber also requires the max_replication_slots
   be set to configure how many replication origins can be tracked.  In this
   case it should be set to at least the number of subscriptions that will be
   added to the subscriber.  max_logical_replication_workers
   must be set to at least the number of subscriptions, again plus some reserve
   for the table synchronization.  Additionally the max_worker_processes
   may need to be adjusted to accommodate for replication workers, at least
   (max_logical_replication_workers
   + 1).  Note that some extensions and parallel queries
   also take worker slots from max_worker_processes.