Information
The logging collector is a background process that captures log messages sent to stderr and redirects them into log files. The logging_collector setting must be enabled in order for this process to run. It can only be set at server start.
Rationale:
The logging collector approach is often more useful than logging to syslog, since some types of messages might not appear in syslog output. One common example is dynamic-linker failure message; another may be error messages produced by scripts such as archive_command.
Note: This setting must be enabled when log_destination is either 'stderr' or 'csvlog' and for certain other logging parameters to take effect.
Solution
Execute the following SQL statement(s) to remediate this setting:
postgres=# alter system set logging_collector = 'on';
ALTER SYSTEM
Unfortunately, this setting can only be changed at server (re)start. As root, restart the PostgreSQL service for this change to take effect:
[root@centos7 ~]# whoami
root
[root@centos7 ~]# systemctl restart postgresql-11
[root@centos7 ~]# systemctl status postgresql-11|grep 'ago$'
Active: active (running) since <date>; 1s ago
Default Value:
on