Termination of NetConf Sessions
OAM interface specification
The figure below shows the generic principals of reading and writing operations via TLS/NetConf/Yang for configuration management.
Subject of this discussion is about implementing a mechanisme, which ensures that the NetConf session is closed after NetConf operations.
Typical NetConf client behavior
Usually NetConf clients do not terminate the NetConf session automatically. With respect to ONAP-CCSDK/OpenDaylight; once ODL is aware of a NetConf server by creating a mountpoint in odl-netconf-topology, it has an automated mechanism trying to connect that NetConf server. In case the NetConf session is lost, it automatically will re-connect.
Such mechanism needs to be "disabled" and the NetConf Session termination request must be implemented.
Proposed solution
Add an optional attribute called 'permanet-connection' to the netconf-node-topology.yang to grouping 'netconf-node-connection-parameters' with type BOOLEAN and default value TRUE.
This way applications controlling the NetConf connection can distinguish between the currently existing behavior and the new O1-interface-behavior. Old implementations are not affected, because the new attribute is optional and its default value is according to the current behavior.
Proposed modification on network-node-topology.yang:
Proposed change
...
149 }
new
new leaf permanent-connection {
new config true;
new type boolean;
new default true;
new description "If false, the connector disconnects, by sending <close-session>
after a transaction is completed - usually after the response
of <unlock>."
new }
150
151 leaf connection-timeout-millis {
152 description "Specifies timeout in milliseconds after which connection must be established.";
...