httpd _monitor_0 on one of the controller is failing to start

Issue

• httpd service is not starting in abc. Below are the details.

  Failed Actions:
  * httpd_monitor_0 on abc 'OCF_PENDING' (196): call=336, status=complete, exitreason='none',
      last-rc-change='Thu Oct 12 01:21:55 2017', queued=0ms, exec=3ms
  
  [root@abc httpd]# systemctl status httpd
  ● httpd.service - The Apache HTTP Server
     Loaded: loaded (/usr/lib/systemd/system/httpd.service; disabled; vendor preset: disabled)
    Drop-In: /usr/lib/systemd/system/httpd.service.d
             └─openstack-dashboard.conf
     Active: failed (Result: exit-code) since Thu 2017-10-12 02:39:37 UTC; 22s ago
       Docs: man:httpd(8)
             man:apachectl(8)
    Process: 29643 ExecStop=/bin/kill -WINCH ${MAINPID} (code=exited, status=1/FAILURE)
    Process: 29641 ExecStart=/usr/sbin/httpd $OPTIONS -DFOREGROUND (code=exited, status=1/FAILURE)
    Process: 29278 ExecStartPre=/usr/bin/python /usr/share/openstack-dashboard/manage.py compress --force (code=exited, status=0/SUCCESS)
    Process: 28970 ExecStartPre=/usr/bin/python /usr/share/openstack-dashboard/manage.py collectstatic --noinput --clear (code=exited, status=0/SUCCESS)
   Main PID: 29641 (code=exited, status=1/FAILURE)
  
  Oct 12 02:39:31 abc.localdomain python[28970]: Deleting 'horizon/lib/jquery-ui/ui/themes/mint-choc/images/ui-icons_f1fd86_256x240.png'
  Oct 12 02:39:31 abc.localdomain python[28970]: Deleting 'horizon/lib/jquery-ui/ui/themes/mint-choc/images/ui-bg_flat_0_aaaaaa_40x100.png'
  Oct 12 02:39:31 abc.localdomain python[28970]: Deleting 'horizon/lib/jquery-ui/ui/themes/mint-choc/images/ui-icons_222222_256x240.png'
  Oct 12 02:39:31 abc.localdomain python[28970]: Deleting 'horizon/lib/jquery-ui/ui/themes/mint-choc/images/ui-bg_gloss-wave_25_453326_500x100.png'
  Oct 12 02:39:37 abc.localdomain systemd[1]: httpd.service: main process exited, code=exited, status=1/FAILURE
  Oct 12 02:39:37 abc.localdomain kill[29643]: kill: cannot find process ""
  Oct 12 02:39:37 abc.localdomain systemd[1]: httpd.service: control process exited, code=exited status=1
  Oct 12 02:39:37 abc.localdomain systemd[1]: Failed to start The Apache HTTP Server.
  Oct 12 02:39:37 abc.localdomain systemd[1]: Unit httpd.service entered failed state.
  Oct 12 02:39:37 abc.localdomain systemd[1]: httpd.service failed.