[ovs-dev] [PATCH] vswitchd: Always configure a default queue for QoS.

Ben Pfaff blp at nicira.com
Wed Feb 15 17:08:58 UTC 2012


On Tue, Feb 14, 2012 at 11:45:17PM -0800, Ethan Jackson wrote:
> > +        (Before version 1.6, Open vSwitch would drop all packets destined for
> > +        the default queue if no configuration was present.)
> 
> Are you sure this is true?  My (admittedly fuzzy) memory tells me that
> un-queued traffic effectively reduces the size of the pipe for the
> queued traffic.  This of, of course, has undesirable results on
> min-rates, but isn't as severe as dropping traffic altogether.  If we
> don't drop unqueued traffic, does forcibly installing a default queue
> still make sense?  The cost of a misconfiguration is significantly
> lower in this case.  I'm curious what your thoughts are.  I dont' feel
> particularly strongly.

In bug #5583 you wrote:

> The issue is not that there is no min_bandwidth. The problem is that
> there is an OVS QoS object configured in the database which has no
> Queues to send traffic through. Thus when traffic destined for eth1 is
> forwarded through the QoS object, it has nowhere to put it and simply
> drops it. This is a misconfiguration likely caused by the controller and
> thus a bug should be filed against them.

And then later, when it was reopened for what turned out to be a
different reason, you wrote:

> There is no default queue so the traffic which isn't hitting the
> configured queue has no bandwidth allocated to it. This is expected
> behavior in this situation. Looks like a configuration error.

Please argue out the situation with yourself and get back to me when
you've come to a conclusion.



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