Comment 0 for bug 1575554

Detailed bug description:
During execution of longevity test on MOS 9.0, I've found a lot of warnings from Neutron about resource_versions dictionary:

neutron-server.log:2016-04-27T02:46:09.627497+00:00 warning: 2016-04-27 02:46:09.624 27817 WARNING neutron.db.agents_db [req-f7f2b2c6-4ef4-45c9-bd9d-9f43c7961658 - - - - -] Dictionary resource_versions for agent L3 agent on host node-59.domain.tld is invalid.
neutron-server.log:2016-04-27T02:46:09.627558+00:00 warning: 2016-04-27 02:46:09.624 27817 WARNING neutron.db.agents_db [req-f7f2b2c6-4ef4-45c9-bd9d-9f43c7961658 - - - - -] Dictionary resource_versions for agent L3 agent on host node-59.domain.tld is invalid.
neutron-server.log:2016-04-27T02:46:09.628482+00:00 warning: 2016-04-27 02:46:09.625 27817 WARNING neutron.db.agents_db [req-f7f2b2c6-4ef4-45c9-bd9d-9f43c7961658 - - - - -] Dictionary resource_versions for agent Metadata agent on host node-60.domain.tld is invalid.
neutron-server.log:2016-04-27T02:46:09.628510+00:00 warning: 2016-04-27 02:46:09.625 27817 WARNING neutron.db.agents_db [req-f7f2b2c6-4ef4-45c9-bd9d-9f43c7961658 - - - - -] Dictionary resource_versions for agent Metadata agent on host node-60.domain.tld is invalid.
neutron-server.log:2016-04-27T02:46:09.628903+00:00 warning: 2016-04-27 02:46:09.626 27817 WARNING neutron.db.agents_db [req-f7f2b2c6-4ef4-45c9-bd9d-9f43c7961658 - - - - -] Dictionary resource_versions for agent Metadata agent on host node-57.domain.tld is invalid.

Steps to reproduce:
1. Start any activity on cluster (run Neutron rally)

Actual result:
1. A lot of traces during execution

Reproducibility:
100%

Workaround:
N/A

Impact:
Unknown. I do not know how Neutron use this dictionary.

Description of the environment:
* MOS 9.0, build 227
* 10 baremetal nodes (12 CPU, 32GB RAM)
* Compute: KVM
* Network: Neutron with VLAN segmentation
* Ceph RBD for volumes (Cinder)
* Ceph RadosGW for objects (Swift API)
* Ceph RBD for ephemeral volumes (Nova)
* Ceph RBD for images (Glance)

Please check diagnostic snapshot:
https://drive.google.com/open?id=0B9tzODpFABxkQnhhS2d2SHNSNG8