[ovs-discuss] Flow removed message bug

Derek Cormier derek.cormier at lab.ntt.co.jp
Fri Feb 18 02:50:17 UTC 2011


Sure, let me explain the problem. I am maintaining a copy of the flows 
in memory outside of the controller (Nox). When a flow is removed, I 
need to remove it from the stored flows. However, if the wildcards are 
not exact in the removed message, I cannot identify exactly which flow 
it is. I could have a flow with those extra fields set to 0 and I would 
think it's that flow being deleted, when it's really a different one.

Thanks,
- Derek

On 02/18/2011 11:40 AM, Justin Pettit wrote:
> Hi, Derek.  I just wanted to let you know that we're still discussing how to best handle this.  How difficult is it from your perspective if OVS continued to behave in this manner?  There was a time when this normalization was more important from a performance perspective than it is now, so we may be able to either stop normalizing or at least store the original wildcards.  However, OVS has behaved this way for a long time, and we haven't heard other application writers have issues with it.  I understand how it could be confusing, though.
>
> --Justin
>
>
> On Feb 16, 2011, at 1:39 AM, Justin Pettit wrote:
>
>> Okay, that makes a bit more sense.  My guess is that if you look in ovs-vswitchd's logs, you'll see some messages about "normalization changed ofp_match".  Internally, we're clearing those other wildcard bits, since they're meaningless for non-IP/ARP flows (such as your flow definition with ethertype of 5).  I'll talk with Ben about how we want to handle this from an OpenFlow-compatiblity standpoint tomorrow.
>>
>> --Justin
>>
>>
>> On Feb 16, 2011, at 12:51 AM, Derek Cormier wrote:
>>
>>> Great. I also made a mistake about the field. It was dl_type, not dl_src. It actually works fine for dl_src.
>>>
>>> - Derek
>>>
>>> On 02/16/2011 05:36 PM, Justin Pettit wrote:
>>>> No problem.  Most of us are subscribed to both.  :-)  We'll take a look at it in the morning, California time.  I don't expect it will be a difficult fix.
>>>>
>>>> Thanks for reporting it.
>>>>
>>>> --Justin
>>>>
>>>>
>>>> On Feb 16, 2011, at 12:26 AM, Derek Cormier wrote:
>>>>
>>>>> Now that I think about it, this should have been posted to the dev board. Sorry about that!
>>>>>
>>>>> - Derek
>>>>>
>>>>> _______________________________________________
>>>>> discuss mailing list
>>>>> discuss at openvswitch.org
>>>>> http://openvswitch.org/mailman/listinfo/discuss_openvswitch.org
>>>>
>
>





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