[ovs-discuss] Questions about IPFIX

Greg Rose gvrose8192 at gmail.com
Tue Jun 6 14:14:51 UTC 2017


On 06/06/2017 05:18 AM, Felix Konstantin Maurer wrote:
> I accidentally only responded to you, so here again what I wrote.
> Thanks for the quick response! If tested it now but so far I see no
> difference. All IPFIX packets have the same flowStartDelta and flowEndDelta.
> 
> Furthermore, about the first lines in ipfix_cache_aggregate_entries?
> 
> line 1457
>      to_start = &to_entry->flow_start_timestamp_usec;
>      to_end = &to_entry->flow_end_timestamp_usec;
>      from_start = &from_entry->flow_start_timestamp_usec;
>      from_end = &from_entry->flow_end_timestamp_usec;
> 
>      if (*to_start > *from_start) {
>          *to_start = *from_start;
>      }
>      if (*to_end < *from_end) {
>          *to_end = *from_end;
>      }
> 
> Is that not supposed to update the timestamps of the old entry, into
> which the new stats are merged?

Yes, but apparently it's not working right.  I'll be setting up an ipfix
configuration today so let me do some further testing/debugging.

Thanks for your help!

- Greg

> 
> Regards
> Felix
> 
> On 06/06/2017 01:16 AM, Greg Rose wrote:
>> On 06/02/2017 03:06 PM, Ben Pfaff wrote:
>>> On Fri, Jun 02, 2017 at 02:42:49PM -0700, Greg Rose wrote:
>>>> On 06/02/2017 09:08 AM, Ben Pfaff wrote:
>>>>> ipfix_cache_entry_init() initializes the start and end to be the same:
>>>>>
>>>>>           xgettimeofday(&now);
>>>>>           entry->flow_end_timestamp_usec = now.tv_usec + 1000000LL *
>>> now.tv_sec;
>>>>>           entry->flow_start_timestamp_usec =
>>> entry->flow_end_timestamp_usec;
>>>>>
>>>>> and then I don't see anything that ever updates the "end" time.  I
>>> guess
>>>>> that's the issue.
>>>>
>>>>   From looking at the code it appears to me that the
>>> ipfix_cache_update() function isn't doing
>>>> anything to update the time stamps.  It updates the stats but the
>>> stats function doesn't update
>>>> time stamps.  From what I can tell though that seems the place where
>>> it should be updated.  I can
>>>> try whipping up a bug fix patch for this if ipfix_cache_update() is
>>> the right place to do the time
>>>> stamp update.
>>>
>>> Seems reasonable.
>>>
>> I've posted a patch for this here:
>>
>> https://patchwork.ozlabs.org/patch/771459/
>>
>> Felix,
>>
>> can you test it?  I'm getting set up to test ipfix but probably won't be
>> able to test the patch until tomorrow.
>>
>> Thanks,
>>
>> - Greg
> 



More information about the discuss mailing list