Federator behavior upon flow removal

[aekom87]

Dear Odenos community,

We observed the following behavior which seems a bit strange for us.

We have a following Odenos configuration:

            LogicComponent
                  |
            FederatedNetwork
                  |
               Federator
             /           \
    OriginalNet1      OriginalNet2
          |                    |
    Provider1              Provider2

When a flow is removed from the FederatedNetwork (by the LocigComponent), Federator sends DELETE requests to both original networks and immediately reports the federated flow deleted (sends status NONE to the FederatedNetwork).

As a result, LogicComponent considers the flow deleted immediately, even though it actually may take some time for Provider's to delete the flow from the physical equipment. Thus the system becomes desynchronized.

It is contrary to the Federator behavior in the case of flow establishment. When a new flow is added to the FederatedNetwork, Federator sends PUT requests to all original networks and waits until all parts of the flow become established. Only after that Federator changes status of the federated flow to ESTABLISHED.

So our question is whether such Odenos behavior is considered normal or faulty?

Thanks in advance,
Andrey K

[haizawa]

Hello,

The behavior in your description is normal.

Sequence of flow deletion is shown in the following URL.
https://github.com/o3project/odenos/blob/develop/doc/api/DataClass.md#delete
Federator behaves as like [Driver] in the sequence.

If you need a synchronized behavior, please make the flow invalid before deleting the flow.
See following URL how to make a flow invalid
https://github.com/o3project/odenos/blob/develop/doc/api/DataClass.md#invalid

Best Regards,

[aekom87]

Hi,

I would say that

Federator behaves as like [Driver] in the sequence

is not quite true.
According to the sequence, Driver sends the PUT flow(stats:none) message only after a confirmation from Physical Switch that the flow has been actually deleted.
On the contrary, Federator sends the PUT flow(stats:none) message immediately, not waiting for confirmations from drivers.

If a logic component is performing rerouting (i.e. deleting a flow on a failed path and installing a new flow on a new path), it has to wait for the moment when the old flow is actually removed from physical switches. Otherwise install of the new flow will fail.

But it looks impossible with the current behavior of the Federator component.

[haizawa]

Hello,

We think your rerouting scenario can be realized as following 3 steps.

step 1) making old flow invalid.
A logic component which triggers rerouting makes the old flow invalid before deleting the flow.
We assume the driver removes the old flow from physical switches.

See following URL how to make a flow invalid
https://github.com/o3project/odenos/blob/develop/doc/api/DataClass.md#invalid

step 2)deleting the old flow information in ODENOS.
The logic component deletes the old flow information, which has already been invalid.
We assume the old flow information is deleted in ODENOS.

Sequence of flow deletion is shown in the following URL.
https://github.com/o3project/odenos/blob/develop/doc/api/DataClass.md#delete

step 3)creating a new flow.
The logic component creates a new flow.
We assume the driver installs a new flow to physical switches.

Best Regards,