Description of problem:
tried to deploy overcloud and failed.
then tried to troubleshoot and ran:
heat stack-list
got timeout 

Version-Release number of selected component (if applicable):
$ rpm -qa | grep tripleo
openstack-tripleo-puppet-elements-0.0.1.dev55-1.el7ost.noarch
tripleo-common-0.0.1-dev5.el7.centos.noarch
openstack-tripleo-heat-templates-0.8.6-dev15.el7.centos.noarch
openstack-tripleo-0.0.6-dev1717.el7.centos.noarch
openstack-tripleo-image-elements-0.9.6-dev4.el7.centos.noarch


How reproducible:
100%

Steps to Reproduce:
1.run heat stack-list
2.
3.

Actual results:
Timeout

Expected results:
an empty / or a full stack list is shown

Additional info:
$ sudo grep ERROR /var/log/heat/*.*
/var/log/heat/heat-api.log:2015-06-01 06:22:19.277 29558 ERROR heat.common.wsgi [req-5810038a-42ab-4876-85a2-a0f0e9d06e4b - admin] Unexpected error occurred serving API: Timed out waiting for a reply to message ID c0a1e81f97974e30b8aa35a778908638
/var/log/heat/heat-api.log:2015-06-01 06:24:11.787 29558 ERROR heat.common.wsgi [req-2131e487-a507-4ac5-9354-b1c9c6df44fa - admin] Unexpected error occurred serving API: Timed out waiting for a reply to message ID f1a14b5c8aa24b2680d2095cc2a156f0
/var/log/heat/heat-api.log:2015-06-01 06:28:12.936 29558 ERROR heat.common.wsgi [req-f62fcbbf-d7a7-4e03-be19-3d7fd12b1b09 - admin] Unexpected error occurred serving API: Timed out waiting for a reply to message ID 641dd56e22024a02afd07a0c67c028d6
/var/log/heat/heat-api.log:2015-06-01 06:31:55.753 29558 ERROR heat.common.wsgi [req-317e66b0-1553-4fbc-bc5c-d2f82bb4e918 - admin] Unexpected error occurred serving API: Timed out waiting for a reply to message ID 1f7379dd757447f2a9e2e30942923806
/var/log/heat/heat-api.log:2015-06-01 06:33:16.099 29558 ERROR heat.common.wsgi [req-615e17ae-000d-4cd5-978b-6139dca06f20 - admin] Unexpected error occurred serving API: Timed out waiting for a reply to message ID 9c435d98ceae49b088a5ed8458835990
/var/log/heat/heat-api.log:2015-06-01 06:34:18.955 29558 ERROR heat.common.wsgi [req-f995c68b-3387-4abe-81f7-0a20334f39cc - admin] Unexpected error occurred serving API: Timed out waiting for a reply to message ID 51b89c186a6f40da96695eb77694f44b
/var/log/heat/heat-api.log:2015-06-01 06:41:33.069 29558 ERROR heat.common.wsgi [req-3ac8736d-d9b5-43c7-ad24-584c51bc6d20 - admin] Unexpected error occurred serving API: Timed out waiting for a reply to message ID cef1a57064644c81993b214e140dad9b
/var/log/heat/heat-api.log-20150531:2015-05-28 18:31:34.711 29558 ERROR heat.common.wsgi [req-703f6f87-6e7d-4a3a-a110-4f3ee27a844b admin admin] Exception handling resource: 'NoneType' object is not iterable
/var/log/heat/heat-api.log-20150531:2015-05-28 19:06:26.689 29558 ERROR heat.common.wsgi [req-b3e5820f-0c43-4d40-82fc-01cf1208a540 admin admin] Exception handling resource: 'NoneType' object is not iterable
/var/log/heat/heat-api.log-20150531:2015-05-28 19:06:47.615 29558 ERROR heat.common.wsgi [req-c5436ade-b57a-4cb4-996d-f13499806658 admin admin] Exception handling resource: 'NoneType' object is not iterable
/var/log/heat/heat-api.log-20150531:2015-05-28 19:07:26.294 29558 ERROR heat.common.wsgi [req-70d81a0d-13bd-471f-ad1f-1554cee2884f admin admin] Exception handling resource: 'NoneType' object is not iterable
/var/log/heat/heat-api.log-20150531:2015-05-28 19:10:47.163 29558 ERROR heat.common.wsgi [req-2464932f-e87f-44f9-a25e-9d38bd1c9a5d admin admin] Exception handling resource: 'NoneType' object is not iterable
/var/log/heat/heat-engine.log:2015-06-01 06:19:02.237 29587 ERROR heat.engine.resources.openstack.heat.software_deployment [-] Deployment to server failed: deploy_status_code : Deployment exited with non-zero status code: 1
/var/log/heat/heat-engine.log:2015-06-01 06:19:03.323 29587 ERROR heat.engine.resources.openstack.heat.software_deployment [-] Deployment to server failed: deploy_status_code : Deployment exited with non-zero status code: 1
/var/log/heat/heat-engine.log-20150531:2015-05-28 09:47:20.730 29587 DEBUG oslo_db.sqlalchemy.session [req-c6dd13df-390c-43d9-a7ee-4b356370e903 - -] MySQL server mode set to STRICT_TRANS_TABLES,STRICT_ALL_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,TRADITIONAL,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION _check_effective_sql_mode /usr/lib/python2.7/site-packages/oslo_db/sqlalchemy/session.py:513


env:  root.lab.tlv.redhat.com
leaving the env so someone could look at .