[ovs-discuss] MAC_Binding\" table to have identical values

[Numan Siddique]

On Mon, Oct 18, 2021 at 7:55 AM Daniel Alvarez Sanchez
<dalvarez at redhat.com> wrote:
>
>
>
> On Mon, Oct 18, 2021 at 1:12 PM Ammad Syed <syedammad83 at gmail.com> wrote:
>>
>> Hi Brendan,
>>
>> Not sure but this could be related to the patch below in neutron that was recently released.
>>
>> https://opendev.org/openstack/neutron/commit/f6c35527698119ee6f73a6a3613c9beebb563840
>
>
> Not really, as this commit that you refer to is to reduce the memory footprint in the neutron-server process itself. Neutron never inserts anything into the MAC_Binding table.
> However, we landed another patch [0] that will likely minimize this issue as it will reduce the MAC_Binding insertions, limiting them only to MAC addresses that need to be reached out by the overlay.
>
> Thanks!
> daniel
>
> [0] https://review.opendev.org/c/openstack/neutron/+/813610
>
>
>>
>>
>> Ammad
>>
>> On Mon, Oct 18, 2021 at 3:40 PM Brendan Doyle <brendan.doyle at oracle.com> wrote:
>>>
>>>
>>> I too am seeing many entries in the ovn-controller log like these:
>>>
>>> ovn/ovn-controller.log:2021-10-18T09:50:46.984Z|00164|ovsdb_idl|WARN|transaction error: {"details":"Transaction causes multiple rows in \"MAC_Binding\" table to have identical values (lr_vcn6727324-ls_vcn6727324_external_ugw and \"253.255.80.18\") for index on columns \"logical_port\" and \"ip\".  First row, with UUID 614509d1-5dfc-4268-94b7-6190c1bd8c58, was inserted by this transaction.  Second row, with UUID 5b56044f-7e62-4e6b-b559-2bca31ad5ab0, existed in the database before this transaction and was not modified by the transaction.","error":"constraint violation"}
>>>
>>>
>>> So with my limited understanding of the MAC_Binding table I'm wondering are these benign?
>
>
> I think it's benign
>>>
>>>
>>> In that is it that we for what ever reason have decided that we need to do an ARP to discover
>>> a MAC, then ovn-controller tries to add the discovered MAC to the MAC_Binding only to find
>>> that it is already there. In which case the question is why was an ARP request sent when
>>> we already had a MAC binding.

FYI,  ovn-controller also learns from the ARP requests received from
external which can be
turned off if desired with the option - always_learn_from_arp_request
set in the logical router's options
column.

I don't think ovn-controller will generate an ARP request if its
already learnt.  Looks to me
multiple ovn-controller try to learn from an ARP request originated
from external and ofcourse
only one will be able to write to the mac_binding entry and others would fail.

Thanks
Numan



>>>
>>> For me these are only ever seen on Distributed router Port Gateways.
>>>
>>>
>>> On 12/10/2021 13:06, Ammad Syed wrote:
>>>
>>> Hi,
>>>
>>> I am using openstack with ml2/ovn. I have two gateway chassis whenever I shutdown one chassis and bring it back online, I see below error in ovn-controller logs.
>>>
>>> Can you please advise the way to fix it ?
>>>
>>> 2021-10-12T11:49:22.124Z|00511|binding|INFO|cr-lrp-4c882760-15b1-4cf4-b680-53e88880e928: Claiming fa:16:3e:55:12:5a 101.53.244.97/24
>>> 2021-10-12T11:49:22.126Z|00512|binding|INFO|Releasing lport cr-lrp-4c882760-15b1-4cf4-b680-53e88880e928 from this chassis.
>>> 2021-10-12T11:50:32.032Z|00513|ovsdb_idl|WARN|transaction error: {"details":"Transaction causes multiple rows in \"MAC_Binding\" table to have identical values (lrp-4c882760-15b1-4cf4-b680-53e88880e928 and \"fe80::6a4f:64ff:fef7:8c0\") for index on columns \"logical_port\" and \"ip\".  First row, with UUID cbc847e6-75e4-4d73-9906-4fef221cad38, was inserted by this transaction.  Second row, with UUID bcac2e3e-5f32-411a-afcf-3249b85700f4, existed in the database before this transaction and was not modified by the transaction.","error":"constraint violation"}
>>>
>>> Ammad
>>>
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>>>
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>>
>>
>>
>> --
>> Regards,
>>
>>
>> Syed Ammad Ali
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>
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