[prev in list] [next in list] [prev in thread] [next in thread] 

List:       openvswitch-discuss
Subject:    [ovs-discuss] Flow removed reporting statistics with value 0
From:       super.ismiti () gmail ! com (Ricardo Schmidt)
Date:       2014-05-28 18:45:33
Message-ID: 57C0B11B-33A0-4E02-8538-0F7B5288B226 () gmail ! com
[Download RAW message or body]

Thanks Ben, that explains a lot. Is this documented somewhere that we can refer to?

> On May 28, 2014, at 19:57, Ben Pfaff <blp at nicira.com> wrote:
> 
>> On Wed, May 28, 2014 at 07:51:26PM +0200, Ricardo Schmidt wrote:
>> We are running OpenFlow 1.3, OVS 2.1.2, and Ryu. Switch and controller are
>> in the same machine with virtualized interfaces.
>> 
>> We are running some stress tests on OVS to check the accuracy of the
>> reported statistics from flow removed messages.
>> 
>> In a first test we inject an average of 100 simultaneous flows per sec in
>> the switch port, in the second an average of 250 flows/s and in the third
>> an average of 500 flows/s.
>> 
>> It seems that the more flows/s the more erratic the behavior of the
>> counters. The total sum of reported bytes and packets at the end (summing
>> all flow removed messages) is always less than the number of injected ones.
>> This problem increases with the increasing number of flows/s. We do make
>> sure that our flow mod always include the flag asking to the switch to send
>> the flow removed upon entry expiration.
>> 
>> In the third case, with 500 flows/s, not only the counters are off, but we
>> also surprisingly see many flow removed messages in which counters have
>> value of zero. That is, as if the total forwarded packets and bytes was
>> zero.
>> 
>> Does anyone has an idea of what might be happening?
> 
> Counters only get updated about once a second.  If your flows are
> short, they might never get updated.

[prev in list] [next in list] [prev in thread] [next in thread]