As I mentioned, I have 2 servers connected via 1Gig cable. I have installed
OVS with DPDK on server one. I have a switch OVS_BR_LEAF_1 on it which runs
in user-space. I tried doing QoS traffic shaping as done in the link you
mentioned.

I have following flow entries in my switch
#vs-ofctl add-flow OVS_BR_LEAF_1
priority=6000,in_port=LOCAL,actions=set_queue:1,normal
#ovs-ofctl add-flow OVS_BR_LEAF_1 priority=6000,in_port=2,actions=normal

I have connected eth3 to ovs on port 2. I want traffic going from server
one to server two to observer 20Mbps traffic rate.

To  deconfigure  any old QoS record from eth3 and then delete the QoS
record, I did:
#ovs-vsctl clear Port eth3 qos

Then, I added following configuration:

#ovs-vsctl -- set port eth3 qos=@newqos -- --id=@newqos create qos
type=linux-htb other-config:max-rate=500000000 queues:1=@q1 -- --id=@q1
create queue other-config:max-rate=20000000

Then I checked rate via iperf and got around 478Mbps, which is closer to
the max rate of the default queue i.e. 500000000. I have checked it
multiple times with different values of default queue's max-rate,
I just get whatever max-rate of default queue I specify, the queue q1 never
works.

Please help.


On Thu, Dec 13, 2018 at 5:47 AM Justin Pettit <[email protected]> wrote:

>
> > On Dec 12, 2018, at 12:32 AM, Ramzah Rehman <[email protected]>
> wrote:
> >
> > I have tested meter action in OpenFLow. I have drawn following
> conclusions:
> >
> >       • TCP
> >               • Conclusion: meter works fine for low rate-limiting
> values (till ~100Mbps). However, for higher values, the expected bandwidth
> is relatively very low.
> >       • UDP:
> >               • Conclusion: meter action not supported for UDP
> >
> > Please let me know Why I am seeing this behavior with TCP traffic? Is it
> expected? If so, How can I get expected bandwidth equal to the rate I
> specify in OpenFlow meter?
>
> TCP throughput has a tendency to act erratically to packets dropping, so
> it can be hard to exactly tune throughput.  You might try configuring
> different burst sizes at different rates to see if that helps.  However, if
> you need to rate-limit TCP, you're probably better off using the QoS
> configuration with traffic shaping, since that will delay packets instead
> of dropping them.  Some of this is discussed in the FAQ:
>
>         http://docs.openvswitch.org/en/latest/faq/qos/
>
> I would recommend using HTB for less than 100Mbps and HFSC for less than
> 1Gbps.  Anything above that will likely have poor performance due to the
> overhead of performing QoS in software.
>
> > Also, does meter action work for UDP traffic?
>
> Yes, I would expect it to work.  It should perform more predictably than
> TCP.
>
> How did you configure the flows?  Are you using the kernel or userspace
> datapath?  If you're using the kernel, what kernel version are you using?
> There are a few kernel versions that have issues due to a bug in the
> upstream kernel.
>
> --Justin
>
>
>
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