Description of problem:
ceilometer-api does not respond api calls or curl commands.
i. This is a director based environment which was initially working.
ii. It has enough space & mongodb is around 45G .
iii. With debug & verbose enabled , ceilometer does not log any event when api calls are made .
iv. Cannot use curl to the haproxy backend for ceilometer , even from the local controller ip . Firewall is taken care of .
v. tcpdump on internal endpoint url shows lot of activity .
vi telnet to internal/backend ip works 

Version-Release number of selected component (if applicable):
RHOS7
openstack-ceilometer-alarm-2015.1.2-1.el7ost.noarch         Fri Mar 11 20:47:23 2016
openstack-ceilometer-api-2015.1.2-1.el7ost.noarch           Fri Mar 11 20:47:23 2016
openstack-ceilometer-central-2015.1.2-1.el7ost.noarch       Fri Mar 11 20:47:22 2016
openstack-ceilometer-collector-2015.1.2-1.el7ost.noarch     Fri Mar 11 20:47:22 2016
openstack-ceilometer-common-2015.1.2-1.el7ost.noarch        Fri Mar 11 20:45:52 2016
openstack-ceilometer-compute-2015.1.2-1.el7ost.noarch       Fri Mar 11 20:47:23 2016
openstack-ceilometer-notification-2015.1.2-1.el7ost.noarch  Fri Mar 11 20:45:52 2016
python-ceilometer-2015.1.2-1.el7ost.noarch                  Fri Mar 11 20:45:51 2016
python-ceilometerclient-1.0.14-1.el7ost.noarch              Fri Mar 11 20:38:22 2016

How reproducible:
No. Only on customer environment

Steps to Reproduce:
1.
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Actual results:


Expected results:


Additional info:
[collab-shell] https://gitlab.cee.redhat.com/gss-tools/collab-shell

    # ssh your_kerb.redhat.com
    # cd /cases/01714179