BUG #16261: Not able to start Postgres

The following bug has been logged on the website:

Bug reference:      16261
Logged by:          Abhishree Nagesh
Email address:      abhishreehn@crgroup.co.in
PostgreSQL version: 9.6.11
Operating system:   linux
Description:

Jira the atlassian application is connected to Postgressql.

After restarting the server we're unable to start postgresql service. But
the application is up but gives the error page as unable to connect to
datatbase.

FOllowing is the error we are facing.
Kindly look into that
hence its production.

[root@ip-172-22-36-169 ~]# systemctl status  postgresql-9.6.service
● postgresql-9.6.service - SYSV: PostgreSQL database server.
   Loaded: loaded (/etc/rc.d/init.d/postgresql-9.6; bad; vendor preset:
disabled)
   Active: failed (Result: exit-code) since Mon 2020-02-17 10:01:51 UTC; 18s
ago
     Docs: man:systemd-sysv-generator(8)
  Process: 750 ExecStart=/etc/rc.d/init.d/postgresql-9.6 start (code=exited,
status=1/FAILURE)

Feb 17 10:01:49 ip-172-22-36-169.ap-south-1.compute.internal systemd[1]:
Starting SYSV: PostgreSQL database server....
Feb 17 10:01:51 ip-172-22-36-169.ap-south-1.compute.internal
postgresql-9.6[750]: Starting postgresql-9.6 service: [FAILED]
Feb 17 10:01:51 ip-172-22-36-169.ap-south-1.compute.internal systemd[1]:
postgresql-9.6.service: control process exited, code=exited status=1
Feb 17 10:01:51 ip-172-22-36-169.ap-south-1.compute.internal systemd[1]:
Failed to start SYSV: PostgreSQL database server..
Feb 17 10:01:51 ip-172-22-36-169.ap-south-1.compute.internal systemd[1]:
Unit postgresql-9.6.service entered failed state.
Feb 17 10:01:51 ip-172-22-36-169.ap-south-1.compute.internal systemd[1]:
postgresql-9.6.service failed.
[root@ip-172-22-36-169 ~]#