I don't get it. Why is it a problem taking a pg_basebackup of the new master to re-seed the old master (which is now a slave) and then promoting it to master again?
Or does pg_rewind offer a way to do this that doesn't require taking the current master offline when you promote a slave?
Or does pg_rewind offer a way to do this that doesn't require taking the current master offline when you promote a slave?