Cannot remove idle connections to a Postgres database

Question

I need to delete a database. But the database cannot be deleted due to some active sessions using the database. I then run the command

psql -c "select pg_terminate_backend(procpid) from pg_stat_activity where procpid<> pg_backend_pid() and datname='mydb"
 pg_terminate_backend 
----------------------
 t
 t
 t
 t
 (4 rows)

to delete the sessions. However, the sessions come back with different process ids.

psql -c "select * from pg_stat_activity where datname='mydb';"
 datid  |   datname   | procpid | usesysid |   usename   | current_query |    waiting | xact_start |          query_start          |         backend_start         | client_addr | client_port 
--------+-------------+---------+----------+-------------+---------------+---------+------------+-------------------------------+-------------------------------+-------------+-------------
 220030 | mydb |   25454 |   189669 | myname | <IDLE>        | f       |            | 2018-05-17 15:13:04.741252-05 | 2018-05-17 15:12:12.480389-05 | ::1         |       59540
 220030 | mydb |   25475 |   189669 | myname | <IDLE>        | f       |            | 2018-05-17 15:13:04.903452-05 | 2018-05-17 15:12:12.559564-05 | ::1         |       59542
 220030 | mydb |   25639 |   189669 | myname | <IDLE>        | f       |            | 2018-05-17 15:13:04.731736-05 | 2018-05-17 15:12:12.969821-05 | ::1         |       59546
 220030 | mydb |   25640 |   189669 | myname | <IDLE>        | f       |            | 2018-05-17 15:13:04.735792-05 | 2018-05-17 15:12:12.984415-05 | ::1         |       59548

(4 rows)

My PostgreSQL is 8.4.20. Why do the connections keep on comming back? How can I completely remove them?

Answer 1

It seems there is an always-running program that reconnects to this database as soon as it's disconnected.

Before terminating the connections, you might prevent this from happening again with:

REVOKE CONNECT ON DATABASE mydb FROM public, myname;