Description of problem:
Referring to below OVN architectural model, OVN-Southbound DB which is present in Controller is responsible to manage the transport node via ovn-controller which has resided in all compute nodes.

                                         CMS
                                          |
                                          |
                              +-----------|-----------+ \
                              |           |           |   \
                              |     OVN/CMS Plugin    |	   \
                              |           |           |     \
                              |           |           |      \
                              |   OVN Northbound DB   |       \
                              |           |           |       --->> Overcloud Controller
                              |           |           |	     /
                              |       ovn-northd      |     /
                              |           |           |    /
                              +-----------|-----------+	  /
                                          |		 /
                                          |		/
                                +-------------------+ /
                                | OVN Southbound DB |/
                                +-------------------+
                                          |
                                          |
                       +------------------+------------------+
                       |                  |                  | ------>> Overcloud Compute
         HV 1          |                  |    HV n          |
       +---------------|---------------+  .  +---------------|---------------+
       |               |               |  .  |               |               |
       |        ovn-controller         |  .  |        ovn-controller         |
       |         |          |          |  .  |         |          |          |
       |         |          |          |     |         |          |          |
       |  ovs-vswitchd   ovsdb-server  |     |  ovs-vswitchd   ovsdb-server  |
       |                               |     |                               |
       +-------------------------------+     +-------------------------------+

Ideally, for any downtime in ovn-controller(in Compute), there should be a mechanism in ovn control-plane which can capture the health status of south-bound devices (ovn-controller, ovs-vswitchd , ovsdb-server).
In RHOSP14 testing, when we restart the ovn-controller container (in Compute), there is no event has captured neither in OVN logs in Controller node.

I am not sure if this is a flaw in the OVN architecture model or we are hitting any known bug/RFE. Please guide us for a better understanding of this monitor mechanism in OVN.


Version-Release number of selected component (if applicable):
Red Hat OpenStack 14


Steps to Reproduce:

1. Monitor all the OVN logs reside in overcloud controller node.
   # tailf /var/log/containers/openvswitch/ovn-northd.log /var/log/containers/openvswitch/ovsdb-server-nb.log /var/log/containers/openvswitch/ovsdb-server-sb.log

2. In Compute node. we restarted below docker service and ovs systemd service. We noticed the logs has captured in only ovn-controller.log resides in compute nodes
	@compute-0 ~]# systemctl restart ovsdb-server.service ovs-vswitchd.service openvswitch.service | sleep 10 |docker restart ovn_controller | sleep 10 | docker restart ovn_metadata_agent
	
	@compute-0 ~]# tailf /var/log/containers/openvswitch/ovn-controller.log
	2018-12-28T06:59:35.900Z|00040|fatal_signal|WARN|terminating with signal 15 (Terminated)
	2018-12-28T06:59:36.263Z|00001|vlog|INFO|opened log file /var/log/openvswitch/ovn-controller.log
	2018-12-28T06:59:36.264Z|00002|reconnect|INFO|unix:/run/openvswitch/db.sock: connecting...
	2018-12-28T06:59:36.264Z|00003|reconnect|INFO|unix:/run/openvswitch/db.sock: connected
	2018-12-28T06:59:36.267Z|00004|reconnect|INFO|tcp:172.17.1.17:6642: connecting...
	2018-12-28T06:59:37.269Z|00005|reconnect|INFO|tcp:172.17.1.17:6642: connection attempt timed out
	2018-12-28T06:59:38.270Z|00006|reconnect|INFO|tcp:172.17.1.17:6642: connecting...
	2018-12-28T06:59:38.271Z|00007|reconnect|INFO|tcp:172.17.1.17:6642: connected
	2018-12-28T06:59:38.277Z|00008|jsonrpc|WARN|unix:/run/openvswitch/db.sock: send error: Broken pipe
	2018-12-28T06:59:38.277Z|00009|reconnect|WARN|unix:/run/openvswitch/db.sock: connection dropped (Broken pipe)
	2018-12-28T06:59:38.282Z|00010|dpif_netlink|INFO|The kernel module does not support meters.
	2018-12-28T06:59:38.284Z|00011|ofctrl|INFO|unix:/var/run/openvswitch/br-int.mgmt: connecting to switch
	2018-12-28T06:59:38.284Z|00012|rconn|INFO|unix:/var/run/openvswitch/br-int.mgmt: connecting...
	2018-12-28T06:59:38.284Z|00013|pinctrl|INFO|unix:/var/run/openvswitch/br-int.mgmt: connecting to switch
	2018-12-28T06:59:38.284Z|00014|rconn|INFO|unix:/var/run/openvswitch/br-int.mgmt: connecting...
	2018-12-28T06:59:38.287Z|00015|rconn|INFO|unix:/var/run/openvswitch/br-int.mgmt: connected
	2018-12-28T06:59:38.288Z|00016|rconn|INFO|unix:/var/run/openvswitch/br-int.mgmt: connected
	2018-12-28T06:59:39.277Z|00017|reconnect|INFO|unix:/run/openvswitch/db.sock: connecting...
	2018-12-28T06:59:39.277Z|00018|reconnect|INFO|unix:/run/openvswitch/db.sock: connected

Expected results:
So, the concern is, in a larger scale environment how effective way OVN Northbound/Southbound DB or ovn-northd (in the controller) can monitor the health of ovn-controller which running in compute nodes.