Re: [Dots] DOTS telemetry Issues picked up in Interop Testing

[[e-mail]]

Re-,

FWIW, I implemented the agreed changes at: https://github.com/boucadair/draft-dots-telemetry/blob/master/draft-ietf-dots-telemetry-07.txt

Cheers,
Med

De : Jon Shallow [mailto:[e-mail]]
Envoyé : lundi 20 avril 2020 15:47
À : BOUCADAIR Mohamed TGI/OLN; [e-mail]
Objet : RE: [Dots] DOTS telemetry Issues picked up in Interop Testing

Hi Med,

See inline.

Regards

Jon

From: Dots [mailto: [e-mail]] On Behalf Of [e-mail]
Sent: 20 April 2020 13:54
To: Jon Shallow; [e-mail]
Subject: Re: [Dots] DOTS telemetry Issues picked up in Interop Testing

Hi Jon,

Thank you for sharing the comments.

Please see

De : Dots [mailto:[e-mail]] De la part de Jon Shallow
Envoyé : lundi 20 avril 2020 14:07
À : [e-mail]
Objet : [Dots] DOTS telemetry Issues picked up in Interop Testing

Hi All,

1)
   DOTS agents MUST NOT send pre-or-ongoing-mitigation telemetry
   messages to the same peer more frequently than once every 'telemetry-
   notify-interval' (Section 6.1).

If I do a PUT /tm-setup, followed immediately by a GET /tm-setup, should the GET fail based on the telemetry-notify-interval, or should telemetry-notify-interval apply individually to PUT. GET and DELETE?
[I may want to do a DELETE (no tsid) followed by a GET to get suitable max/min information and telemetry-notify-interval can easily be more than 1 second. ]

[Med] This rate limit does not apply to these messages; it applies only for notifications;

==
        leaf telemetry-notify-interval {
          type uint32 {
            range "1 .. 3600";
          }
          must '. >= ../../min-config-values/telemetry-notify-interval' {
            error-message
              "The value must be greater than or equal
               to the telemetry-notify-interval in the min-config-values";
          }
          units "seconds";
          description
            "Minimum number of seconds between successive
             telemetry notifications.";
        }
===

We can make the text clear:

OLD:

   DOTS agents MUST NOT send pre-or-ongoing-mitigation telemetry

   messages to the same peer more frequently than once every 'telemetry-

   notify-interval' (Section 6.1<https://tools.ietf.org/html/draft-ietf-dots-telemetry-07#section-6.1>).  If a telemetry notification is sent

   using a block-like transfer mechanism (e.g.,

   [I-D.bosh-core-new-block<https://tools.ietf.org/html/draft-ietf-dots-telemetry-07#ref-I-D.bosh-core-new-block>]), this rate limit policy MUST NOT consider

   these individual blocks as separate notifications, but as a single

   notification.

NEW:

   DOTS agents MUST NOT send pre-or-ongoing-mitigation telemetry

   notifications to the same peer more frequently than once every 'telemetry-

   notify-interval' (Section 6.1<https://tools.ietf.org/html/draft-ietf-dots-telemetry-07#section-6.1>).  If a telemetry notification is sent

   using a block-like transfer mechanism (e.g.,

   [I-D.bosh-core-new-block<https://tools.ietf.org/html/draft-ietf-dots-telemetry-07#ref-I-D.bosh-core-new-block>]), this rate limit policy MUST NOT consider

   these individual blocks as separate notifications, but as a single

   notification.

Jon> This change works for me.

2)
Use of multiple Uri-Query:

Uri-Query: target_prefix=[1.2..3.4]
Uri-Query: target_prefix=[2.3..4.5]
I think this should be OR
[Med] Yes, this is the same interpretation when we include target-prefix in the message body.

Uri-Query: target_prefix=[1.2..3.4]
Uri-Query: target_port=[80]
I think this should be an AND.
[Med] Yes, because the target-port is specifying a subset of ports bound to the target-prefix.

Perhaps we should have operator queries
Uri-Query: target_prefix=[1.2..3.4]
Uri-Query: op=OR
Uri-Query: target_prefix=[2.3..4.5]

Uri-Query: target_prefix=[1.2..3.4]
Uri-Query: op=AND
Uri-Query: target_port=[80]
[Med] I don't think this is needed. We don't specify the operator when we include the target clauses in the message body. The same rules apply. We can clarify this in the text If you think this is needed.

Jon> I think that it is worth stating that the same rules apply for clarification.

Thoughts?

3)
What happens if a Query cannot be supported.

E.g. Uri-Query: target_port=[80] and statistics on the server by a port basis  is not supported.  Do we want to either error out with a 4.0X responses, or should we include a (new additional) YANG body response indicating which Uri-Query is not supported?

[Med] Good point. The client can retrieve during telemetry setup the supported query types + server replies with 4.00 when an invalid query type is used.

Jon> I think the server stating what Queries are supported is a good idea.

Regards

Jon