[pox-dev] Statistics module

[Kouvakas Alexandros]

Yes, indeed the forwarding strategy is the most important but I just want
to test the performance of open vswitch on Planetlab nodes.
So, for starting I am using the l2 learning component.
But isn't it true that the extra RTT delay that I see at the first ping
packet is because of going first to the controller ?


2013/7/31 Murphy McCauley <murphy.mccauley at gmail.com>

> Answers inline.
>
> On Jul 30, 2013, at 9:44 AM, Kouvakas Alexandros wrote:
>
> Pretty nice with this module.
> I would like to ask some more questions. First, where can I find some
> explanation for each parameter for example for FlowStatsReceived or for
> PortStatsReceived ?
>
>
> I think most of the relevant info should be in the OpenFlow spec.  These
> events more or less correspond to stats replies of the respective types.
>  The only thing POX really does beyond what's in the spec is potentially
> collecting several individual stats replies and turning them into a single
> event, which is just to simplify life for people writing controller code a
> bit (according to the spec, a switch can split a reply across several
> messages, but in practice this is annoying to deal with).
>
> Moreover what exactly do we consider as web traffic. As I noticed pings
> between nodes/VMs are not considered as web traffic.
>
>
> This just follows from the simple example on the wiki.  I didn't want to
> dump all the flows on the console -- I wanted to do something a tiny bit
> more interesting.  So if you look at the example on the wiki, you can see
> that it goes through each returned flow and just adds up the bytes used for
> every flow that has a transport protocol source or destination of 80 (line
> 9 on the wiki; there's a similar line in the expanded example).  It's worth
> noting that there's no actual check that it's TCP, so this could also be
> UDP port 80, or ICMP with a type or code of 80.  This is a bug. :)
>
> Finally, is there any method by using POX modules, to measure the time
> that a packet needs to travel from the source to the destination including
> the way pass from the controller.
> For example, when the flow table is empty and I ping from one node to
> another the first packet needs at least the double time than all the other
> packets that follow. That means that the first packet "passes" from the
> controller. So in my case I want to measure these parameters comparing for
> example to the size of the network. Also I will differenciate the size of
> the packets to study how the controller reacts in such cases.
>
>
> I don't have any particular input here, though this or similar problems
> have been discussed before on the nox-dev mailing list and probably
> elsewhere (openflow-discuss?), so you might check the list archives.
>
> I will point out that your example where the first packet goes to the
> controller isn't really fundamental and depends on how you're doing
> forwarding.  Almost all of the POX example forwarding components have
> different behaviors in this respect -- perhaps most dramatically, the
> l2_nx_self_learning and topo_proactive components which really don't behave
> like this at all (in both cases, almost no packets ever go to the
> controller).  And components like those are probably the most realistic.
>
> -- Murphy
>
> 2013/7/29 Murphy McCauley <murphy.mccauley at gmail.com>
>
>> That example is meant to be run from the POX CLI/interpreter (that is, it
>> expects you ran the "py" component), not as a standalone component.
>>
>> You could turn it into a component with a little work (it has already
>> been discussed on the mailing list).  However, there's a "Statistics
>> Collector Example" in the "Third Party" section of the manual wiki which
>> has already done this (and expanded on the original a bit).
>>
>> Hope that helps.
>>
>> -- Murphy
>>
>>
>> On Jul 29, 2013, at 9:26 AM, Kouvakas Alexandros wrote:
>>
>> Hello,
>> I am trying to collect statistics from the ovs. I tried to run the
>> Example - Web flow statistics but I get the following error
>>
>> *[inria_nepi at planetlab2 pox]$ ./pox.py samples.pretty_log
>> forwarding.l2_learning flow-stats
>> POX 0.1.0 (betta) / Copyright 2011-2013 James McCauley, et al.
>> Traceback (most recent call last):
>>   File "/home/inria_nepi/pox/pox/boot.py", line 89, in do_import2
>>     __import__(name, globals(), locals())
>>   File "/home/inria_nepi/pox/ext/flow-stats.py", line 2, in <module>
>>     log = core.getLogger("WebStats")
>> NameError: name 'core' is not defined
>> Could not import module: flow-stats*
>>
>> I
>> am using the betta branch, but I don't think it matters as I get the same
>> error with carp branch.
>>
>> Does anybody knows what happens?
>> Also every suggestion for modules that get statistics from the switch are
>> very welcome.
>>
>> Thanks a lot!
>>
>>
>> --
>> Kouvakas Alexandros
>>
>>
>>
>
>
> --
> Kouvakas Alexandros
>
>
>


-- 
Kouvakas Alexandros
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