Re: [bmwg] Feedback for Benchmarking Methodology for OpenFlow SDN Controller Performance

["Bhuvan \(Veryx Technologies\)" <[e-mail]>]

Hi Brain,

I have a couple of comments which are inline with tag Bhuvan

> -----Original Message-----
> From: Castelli, Brian [mailto:[e-mail]]

> I really like Al¹s suggestion to generalize SDN controller benchmarking
> because 1) the ONF effort is OpenFlow specific and 2) OpenFlow does not
> define SDN. OpenFlow is one of several southbound protocols that can be
> used between a controller function and network node functions. Regardless
> of the maturity of current OpenFlow implementations, I believe that we can
> define a family of benchmarks that have general applicability to SDN
> environments because there are common functions/services that will be
> provided independent of protocol. At the end of the day, protocols are
> commodities. It¹s the service they provide that adds value.

[Bhuvan] I agree with you. We should follow Al's suggestion to make this
draft generic. We should make sure that the draft provides sufficient
clarity so that it can be used on wide range of SDN controllers.

> The current draft contains many of the elements required to sufficiently
> define a benchmarking methodology for a controller function in an SDN
> environment. We should follow Al¹s suggestion, define the taxonomy used in
> the draft, and consolidate wording to make the document easier to read and
> apply.

[Bhuvan] If my understanding is correct, Al's suggestion is to make the
current draft generic enough so that this methodology can be used to
benchmark SDN controllers irrespective of southbound protocols.

> What follows is an attempt to define a higher-level set of SDN controller
test
> cases. It builds on the work done in the draft. I will provide some detail
on
> the first test case in order to establish a cadence. Subsequent test cases
will
> not have the detail, but the ability to iterate over variables and so on
is
> implied.

[Bhuvan] I believe the next set of activities is to make the defined metrics
and methodology generic enough so that it becomes protocol independent.
Secondly the usage of the term testcase in the context of benchmarking is
slightly confusing. The intent of benchmarking is to measure the performance
metric rather than to conclude pass or fail.
 
> The SDN Controller test taxonomy would include:
> 
> - Asynchronous Message Response Rate. A test case to measure AMRR
> would cover a variety of conditions that are analogous to the following
> OpenFlow-specific events:
> 
>   o Packet_in received
>   o Flow expiration received
>   o Link down received
> 
> In other words, AMRR would be used to measure the ability of an SDN
> controller to respond to a variety of asynchronous (i.e. unexpected)
> conditions. One methodology for measurement would be specified by the
> benchmark. The tester would then apply that methodology to packet_ins,
> flow expiration, link down, and whatever other AMR testing is appropriate.
> 
> The AMRR methodology should include iteration variables and goal seeking.
> The tester ought to be able to use the methodology to determine, for
> example, the maximum packet_in AMRR for a variety of conditions, such as
> variations in the number of connected nodes, the complexity of the
> packet_ins, and so on. Variables also include negative testing with
invalid
> packets, for example.
> 
> - Synchronous Message Response Rate. A test case for measuring SMRR
> would cover a variety of conditions analogous to the following OpenFlow-
> specific
> events:
> 
>   o Hello packet exchange
>   o Echo request/response exchange
> 
> - Node Acquisition Rate. A test case for measuring NAR would be a special
> case of SMRR, but it specifically measures the rate at which an SDN
controller
> can connect to nodes in a network.
> 
> - Node Acquisition Maximum. A test case for NAM would measure the
> maximum number of network nodes that an SDN controller can connect to
> without error.
> 
> - FailOver Response Time. There are at least two test cases for measuring
> FORT. One would measure a control cluster¹s ability to survive a
controller
> failure. How long does it take the controller function to be assumed by
> another controller element? Another would measure the controller¹s ability
> to respond to node failures to do things like re-route traffic. How long
does it
> take for the controller to send out commands that handle the error? This
is a
> bit like measuring convergence time, but care must be taken to keep the
> node variables out of the measurement.
> 
> - FailBack Response Time. Test cases for FBRT would be used to measure the
> response time when the controller comes back up or the node comes back
> online. How long does it take the controller to send the commands that
> restore service?

> On 6/23/14, 10:53 AM, "Bhuvan (Veryx Technologies)"
> <[e-mail]> wrote:
> 
> >Hi Al,
> >
> >Thanks for your comment. I do agree with you that there needs to be a
> >common benchmarking mechanism for controller designs performing the
> >same tasks.
> >But the technology is still relatively immature and the approach has
> >various dimensions including centralized control vs distributed control
> >(controller less).
> >Again the centralized control approach uses different programming
> >methods (OpenFlow vs Non OpenFlow).
> >
> >Having said that, for better usability/understanding of the draft and
> >to avoid misinterpretation, I personally feel it would be good to have
> >separate benchmarking methodology for each approach (though the
> metrics
> >remain same).
> >Also we would be happy to continue the effort to extend the same
> >metrics for other approaches too.
> >
> >Please let me know if I've missed something.
> >
> >Sarah/Brain, please also share your thoughts on this.
> >
> >Thanks,
> >Bhuvan
> >
> >-----Original Message-----
> >From: MORTON, ALFRED C (AL) [mailto:[e-mail]]
> >Sent: Saturday, June 21, 2014 6:00 PM
> >To: Castelli, Brian; Banks, Sarah; Bhuvan (Veryx Technologies);
> >[e-mail]
> >Cc: 'Anton Basil'; 'Vishwas Manral'
> >Subject: RE: [bmwg] Feedback for Benchmarking Methodology for
> OpenFlow
> >SDN Controller Performance
> >
> >Hi Brian, Sarah, Bhuvan, and all,
> >
> >a couple of quick answers and a comment:
> >
> >> -----Original Message-----
> >> From: bmwg [mailto:[e-mail]] On Behalf Of Castelli,
> >> Brian
> >...
> >> My two main concerns are getting the terminology right and making
> >> sure that the proposed set of tests will achieve our goals. I believe
> >> those goals ought to include a common taxonomy, enabling
> >> apples-to-apples comparisons, and minimizing the time/work required
> >> to execute the test cases.
> >
> >Great, that's exactly what we are chartered to do in BMWG.
> >http://datatracker.ietf.org/wg/bmwg/charter/
> >
> >
> >>
> >> I am willing to help improve the benchmark. I understand that it is
> >> an early draft. The time is right to make sure that we are developing
> >> the best specification that we can.
> >>
> >> How do we continue this process? Via email to this list? I am willing
> >> to help.
> >
> >It's principally e-mail (just as you've been doing) and face-to-face
> >meetings three times a year.  Sarah mentions that our next meeting is
> >in her home town:
> >http://www.ietf.org/meeting/90/index.html
> >
> >Make some text proposals for the draft, and we can discuss them on the
> >list.
> >
> >Having said that, and recognizing that there appears to be a comparable
> >activity in ONF that (I assume) is OpenFlow-specific, perhaps a way to
> >add value to the industry is to approach the SDN controller problem
> >more generically, such that different controller designs performing the
> >same tasks could be benchmarked as black-boxes.  I realize this
> >approach has substantial implications for the draft, but the benefit of
> >wider applicability.
> >
> >food for thought,
> >Al
> >(as a participant)
> >
> >
> 
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