Opendaylight openflow插件：多个通知开关

Question

I copied some code from the openflow samples (learning switch) to get notified when a switch connects but now, alas, I get many notifications. Here's my code to register a listener:

    WakeupOnNode wakeupListener = new WakeupOnNode(s);


    final InstanceIdentifier<Table> instanceIdentifier = InstanceIdentifier.builder(Nodes.class).child(Node.class).
        augmentation(FlowCapableNode.class).child(Table.class).build();


    final DataTreeIdentifier<Table> dataTreeIdentifier = 
            new DataTreeIdentifier(LogicalDatastoreType.OPERATIONAL, instanceIdentifier);

    this.dataTreeChangeListenerRegistration = this.dataBroker.registerDataTreeChangeListener(dataTreeIdentifier, wakeupListener);

I see multiple notifications in the listener. Not sure why this happens. Perhaps I need to listen on some other identifier (?)

Thanks in advance for any help.

Ranga

Answer 1

You are listening for OpenFlow table updates, which will get you a notification every time an openflow event affects a table on a switch. So you are not listening to the right kind of class.

If you had stopped at InstanceIdentifier.builder(Nodes.class).child(Node.class) you would have had a notification for every time a switch was updated, added or deleted. This sounds like the kind of notification you are looking for. Personally, this is the class I use to listen for new nodes on the topology.

Note, though, that you will still get many notifications.

Since this notification ( Node.class ) is more generic, you will probably have to ignore a lot of 'Update' notifications; this is normal, since this will include all 'Update' notifications from the class you are currently listening to (Table is contained within Node).