14:43:01 test$ psql -p 15432 -c "checkpoint"
CHECKPOINT
14:43:20 test$ psql -p 15432 -c "select slot_name, active, restart_lsn from pg_replication_slots"
 slot_name | active | restart_lsn 
-----------+--------+-------------
 rs        | t      | 0/3047328
(1 row)

14:43:24 test$ psql -p 25432 -c "SELECT pg_last_wal_replay_lsn()"
 pg_last_wal_replay_lsn 
------------------------
 0/3047328
(1 row)


14:43:33 test$ psql -p 15432 -c "select pg_current_wal_lsn()"
 pg_current_wal_lsn 
--------------------
 0/3047328
(1 row)