this is causing some failure(s) in CSIT, so starting with elevated severity as we want to keep CSIT passing 100%

in summary, there is a specific set of steps where the operational store will still contain node data even after the ovs has been disconnected (ovs-vsctl del-manager). In this test, ovs is set to passive mode and the connection
is created via config store request.

steps:

• set ovs to passive
• connect to ovs via ODL NB rest api
• create a new "node" via NB api
• create a qos entry
• create a queue entry
• link the qos and queue to the "node"
• delete the queue entry
• delete the qos entry
• delete the node
• disconnect ovs
• delete the original connection info

at this point the operational will still contain the two nodes.

The CSIT job that can be used to replicate this is here:
https://logs.opendaylight.org/releng/jenkins092/ovsdb-csit-1node-southbound-only-carbon/203/archives/log.html.gz#s1-s4

note the failures in CSIT are happening later, but I am assuming this problem is what is causing the failures in the tests after it.