Open Stack

I run the performance test using iperf3. But the performance is not
increased as theory. I don't know which configuration is not correct.

On Fri, Sep 8, 2023 at 8:57 AM Satish Patel <satish.txt at gmail.com> wrote:

> I would say let's run your same benchmark with OVS-DPDK and tell me if you
> see better performance. I doubt you will see significant performance boot
> but lets see. Please prove me wrong :)
>
> On Thu, Sep 7, 2023 at 9:45 PM Ha Noi <hanoi952022 at gmail.com> wrote:
>
>> Hi Satish,
>>
>> Actually, the guess interface is not using tap anymore.
>>
>>     <interface type='vhostuser'>
>>       <mac address='fa:16:3e:76:77:dd'/>
>>       <source type='unix' path='/var/run/openvswitch/vhu3766ee8a-86'
>> mode='server'/>
>>       <target dev='vhu3766ee8a-86'/>
>>       <model type='virtio'/>
>>       <alias name='net0'/>
>>       <address type='pci' domain='0x0000' bus='0x00' slot='0x03'
>> function='0x0'/>
>>     </interface>
>>
>> It's totally bypass the kernel stack ?
>>
>>
>>
>>
>> On Fri, Sep 8, 2023 at 5:02 AM Satish Patel <satish.txt at gmail.com> wrote:
>>
>>> I did test OVS-DPDK and it helps offload the packet process on compute
>>> nodes, But what about VMs it will still use a tap interface to attach from
>>> compute to vm and bottleneck will be in vm. I strongly believe that we have
>>> to run DPDK based guest to pass through the kernel stack.
>>>
>>> I love to hear from other people if I am missing something here.
>>>
>>> On Thu, Sep 7, 2023 at 5:27 PM Ha Noi <hanoi952022 at gmail.com> wrote:
>>>
>>>> Oh. I heard from someone on the reddit said that Ovs-dpdk is
>>>> transparent with user?
>>>>
>>>> So It’s not correct?
>>>>
>>>> On Thu, 7 Sep 2023 at 22:13 Satish Patel <satish.txt at gmail.com> wrote:
>>>>
>>>>> Because DPDK required DPDK support inside guest VM. It's not
>>>>> suitable for general purpose workload. You need your guest VM network to
>>>>> support DPDK to get 100% throughput.
>>>>>
>>>>> On Thu, Sep 7, 2023 at 8:06 AM Ha Noi <hanoi952022 at gmail.com> wrote:
>>>>>
>>>>>> Hi Satish,
>>>>>>
>>>>>> Why dont you use DPDK?
>>>>>>
>>>>>> Thanks
>>>>>>
>>>>>> On Thu, 7 Sep 2023 at 19:03 Satish Patel <satish.txt at gmail.com>
>>>>>> wrote:
>>>>>>
>>>>>>> I totally agreed with Sean on all his points but trust me, I have
>>>>>>> tried everything possible to tune OS, Network stack, multi-queue, NUMA, CPU
>>>>>>> pinning and name it.. but I didn't get any significant improvement. You may
>>>>>>> gain 2 to 5% gain with all those tweek. I am running the entire workload on
>>>>>>> sriov and life is happy except no LACP bonding.
>>>>>>>
>>>>>>> I am very interesting is this project
>>>>>>> https://docs.openvswitch.org/en/latest/intro/install/afxdp/
>>>>>>>
>>>>>>> On Thu, Sep 7, 2023 at 6:07 AM Ha Noi <hanoi952022 at gmail.com> wrote:
>>>>>>>
>>>>>>>> Dear Smoney,
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> On Thu, Sep 7, 2023 at 12:41 AM <smooney at redhat.com> wrote:
>>>>>>>>
>>>>>>>>> On Wed, 2023-09-06 at 11:43 -0400, Satish Patel wrote:
>>>>>>>>> > Damn! We have noticed the same issue around 40k to 55k PPS.
>>>>>>>>> Trust me
>>>>>>>>> > nothing is wrong in your config. This is just a limitation of
>>>>>>>>> the software
>>>>>>>>> > stack and kernel itself.
>>>>>>>>> its partly determined by your cpu frequency.
>>>>>>>>> kernel ovs of yesteryear could handel about 1mpps total on a ~4GHZ
>>>>>>>>> cpu. with per port troughpuyt being lower dependin on what
>>>>>>>>> qos/firewall
>>>>>>>>> rules that were apllied.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>> My CPU frequency is 3Ghz and using CPU Intel Gold 2nd generation. I
>>>>>>>> think the problem is tuning in the compute node inside. But I cannot find
>>>>>>>> any guide or best practices for it.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>> moving form iptables firewall to ovs firewall can help to some
>>>>>>>>> degree
>>>>>>>>> but your partly trading connection setup time for statead state
>>>>>>>>> troughput
>>>>>>>>> with the overhead of the connection tracker in ovs.
>>>>>>>>>
>>>>>>>>> using stateless security groups can help
>>>>>>>>>
>>>>>>>>> we also recently fixed a regression cause by changes in newer
>>>>>>>>> versions of ovs.
>>>>>>>>> this was notable in goign form rhel 8 to rhel 9 where litrally it
>>>>>>>>> reduced
>>>>>>>>> small packet performce to 1/10th and jumboframes to about 1/2
>>>>>>>>> on master we have a config option that will set the default qos on
>>>>>>>>> a port to linux-noop
>>>>>>>>>
>>>>>>>>> https://github.com/openstack/os-vif/blob/master/vif_plug_ovs/ovs.py#L106-L125
>>>>>>>>>
>>>>>>>>> the backports are propsoed upstream
>>>>>>>>> https://review.opendev.org/q/Id9ef7074634a0f23d67a4401fa8fca363b51bb43
>>>>>>>>> and we have backported this downstream to adress that performance
>>>>>>>>> regression.
>>>>>>>>> the upstram backport is semi stalled just ebcasue we wanted to
>>>>>>>>> disucss if we shoudl make ti opt in
>>>>>>>>> by default upstream while backporting but it might be helpful for
>>>>>>>>> you if this is related to yoru current
>>>>>>>>> issues.
>>>>>>>>>
>>>>>>>>> 40-55 kpps is kind of low for kernel ovs but if you have a low
>>>>>>>>> clockrate cpu, hybrid_plug + incorrect qos
>>>>>>>>> then i could see you hitting such a bottelneck.
>>>>>>>>>
>>>>>>>>> one workaround by the way without the os-vif workaround backported
>>>>>>>>> is to set
>>>>>>>>> /proc/sys/net/core/default_qdisc to not apply any qos or a low
>>>>>>>>> overhead qos type
>>>>>>>>> i.e. sudo sysctl -w net.core.default_qdisc=pfifo_fast
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>>> that may or may not help but i would ensure that your are not
>>>>>>>>> usign somting like fqdel or cake
>>>>>>>>> for net.core.default_qdisc and if you are try changing it to
>>>>>>>>> pfifo_fast and see if that helps.
>>>>>>>>>
>>>>>>>>> there isnet much you can do about the cpu clock rate but ^ is
>>>>>>>>> somethign you can try for free
>>>>>>>>> note it wont actully take effect on an exsitng vm if you jsut
>>>>>>>>> change the default but you can use
>>>>>>>>> tc to also chagne the qdisk for testing. hard rebooting the vm
>>>>>>>>> shoudl also make the default take effect.
>>>>>>>>>
>>>>>>>>> the only other advice i can give assuming kernel ovs is the only
>>>>>>>>> option you have is
>>>>>>>>>
>>>>>>>>> to look at
>>>>>>>>>
>>>>>>>>> https://docs.openstack.org/nova/latest/configuration/config.html#libvirt.rx_queue_size
>>>>>>>>>
>>>>>>>>> https://docs.openstack.org/nova/latest/configuration/config.html#libvirt.tx_queue_size
>>>>>>>>> and
>>>>>>>>>
>>>>>>>>> https://docs.openstack.org/nova/latest/configuration/extra-specs.html#hw:vif_multiqueue_enabled
>>>>>>>>>
>>>>>>>>> if the bottelneck is actully in qemu or the guest kernel rather
>>>>>>>>> then ovs adjusting the rx/tx queue size and
>>>>>>>>> using multi queue can help. it will have no effect if ovs is the
>>>>>>>>> bottel neck.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>> I have set this option to 1024, and enable multiqueue as well. But
>>>>>>>> it did not help.
>>>>>>>>
>>>>>>>>
>>>>>>>>> >
>>>>>>>>> > On Wed, Sep 6, 2023 at 9:21 AM Ha Noi <hanoi952022 at gmail.com>
>>>>>>>>> wrote:
>>>>>>>>> >
>>>>>>>>> > > Hi Satish,
>>>>>>>>> > >
>>>>>>>>> > > Actually, our customer get this issue when the tx/rx above
>>>>>>>>> only 40k pps.
>>>>>>>>> > > So what is the threshold of this throughput for OvS?
>>>>>>>>> > >
>>>>>>>>> > >
>>>>>>>>> > > Thanks and regards
>>>>>>>>> > >
>>>>>>>>> > > On Wed, 6 Sep 2023 at 20:19 Satish Patel <satish.txt at gmail.com>
>>>>>>>>> wrote:
>>>>>>>>> > >
>>>>>>>>> > > > Hi,
>>>>>>>>> > > >
>>>>>>>>> > > > This is normal because OVS or LinuxBridge wire up VMs using
>>>>>>>>> TAP interface
>>>>>>>>> > > > which runs on kernel space and that drives higher interrupt
>>>>>>>>> and that makes
>>>>>>>>> > > > the kernel so busy working on handling packets. Standard
>>>>>>>>> OVS/LinuxBridge
>>>>>>>>> > > > are not meant for higher PPS.
>>>>>>>>> > > >
>>>>>>>>> > > > If you want to handle higher PPS then look for DPDK or SRIOV
>>>>>>>>> deployment.
>>>>>>>>> > > > ( We are running everything in SRIOV because of high PPS
>>>>>>>>> requirement)
>>>>>>>>> > > >
>>>>>>>>> > > > On Tue, Sep 5, 2023 at 11:11 AM Ha Noi <
>>>>>>>>> hanoi952022 at gmail.com> wrote:
>>>>>>>>> > > >
>>>>>>>>> > > > > Hi everyone,
>>>>>>>>> > > > >
>>>>>>>>> > > > > I'm using Openstack Train and Openvswitch for ML2 driver
>>>>>>>>> and GRE for
>>>>>>>>> > > > > tunnel type. I tested our network performance between two
>>>>>>>>> VMs and suffer
>>>>>>>>> > > > > packet loss as below.
>>>>>>>>> > > > >
>>>>>>>>> > > > > VM1: IP: 10.20.1.206
>>>>>>>>> > > > >
>>>>>>>>> > > > > VM2: IP: 10.20.1.154 <https://10.20.1.154/24>
>>>>>>>>> > > > >
>>>>>>>>> > > > > VM3: IP: 10.20.1.72
>>>>>>>>> > > > >
>>>>>>>>> > > > >
>>>>>>>>> > > > > Using iperf3 to testing performance between VM1 and VM2.
>>>>>>>>> > > > >
>>>>>>>>> > > > > Run iperf3 client and server on both VMs.
>>>>>>>>> > > > >
>>>>>>>>> > > > > On VM2: iperf3 -t 10000 -b 130M -l 442 -P 6 -u -c
>>>>>>>>> 10.20.1.206
>>>>>>>>> > > > >
>>>>>>>>> > > > > On VM1: iperf3 -t 10000 -b 130M -l 442 -P 6 -u -c
>>>>>>>>> 10.20.1.154
>>>>>>>>> > > > > <https://10.20.1.154/24>
>>>>>>>>> > > > >
>>>>>>>>> > > > >
>>>>>>>>> > > > > Using VM3 ping into VM1, then the packet is lost and the
>>>>>>>>> latency is
>>>>>>>>> > > > > quite high.
>>>>>>>>> > > > >
>>>>>>>>> > > > >
>>>>>>>>> > > > > ping -i 0.1 10.20.1.206
>>>>>>>>> > > > >
>>>>>>>>> > > > > PING 10.20.1.206 (10.20.1.206) 56(84) bytes of data.
>>>>>>>>> > > > >
>>>>>>>>> > > > > 64 bytes from 10.20.1.206: icmp_seq=1 ttl=64 time=7.70 ms
>>>>>>>>> > > > >
>>>>>>>>> > > > > 64 bytes from 10.20.1.206: icmp_seq=2 ttl=64 time=6.90 ms
>>>>>>>>> > > > >
>>>>>>>>> > > > > 64 bytes from 10.20.1.206: icmp_seq=3 ttl=64 time=7.71 ms
>>>>>>>>> > > > >
>>>>>>>>> > > > > 64 bytes from 10.20.1.206: icmp_seq=4 ttl=64 time=7.98 ms
>>>>>>>>> > > > >
>>>>>>>>> > > > > 64 bytes from 10.20.1.206: icmp_seq=6 ttl=64 time=8.58 ms
>>>>>>>>> > > > >
>>>>>>>>> > > > > 64 bytes from 10.20.1.206: icmp_seq=7 ttl=64 time=8.34 ms
>>>>>>>>> > > > >
>>>>>>>>> > > > > 64 bytes from 10.20.1.206: icmp_seq=8 ttl=64 time=8.09 ms
>>>>>>>>> > > > >
>>>>>>>>> > > > > 64 bytes from 10.20.1.206: icmp_seq=10 ttl=64 time=4.57 ms
>>>>>>>>> > > > >
>>>>>>>>> > > > > 64 bytes from 10.20.1.206: icmp_seq=11 ttl=64 time=8.74 ms
>>>>>>>>> > > > >
>>>>>>>>> > > > > 64 bytes from 10.20.1.206: icmp_seq=12 ttl=64 time=9.37 ms
>>>>>>>>> > > > >
>>>>>>>>> > > > > 64 bytes from 10.20.1.206: icmp_seq=14 ttl=64 time=9.59 ms
>>>>>>>>> > > > >
>>>>>>>>> > > > > 64 bytes from 10.20.1.206: icmp_seq=15 ttl=64 time=7.97 ms
>>>>>>>>> > > > >
>>>>>>>>> > > > > 64 bytes from 10.20.1.206: icmp_seq=16 ttl=64 time=8.72 ms
>>>>>>>>> > > > >
>>>>>>>>> > > > > 64 bytes from 10.20.1.206: icmp_seq=17 ttl=64 time=9.23 ms
>>>>>>>>> > > > >
>>>>>>>>> > > > > ^C
>>>>>>>>> > > > >
>>>>>>>>> > > > > --- 10.20.1.206 ping statistics ---
>>>>>>>>> > > > >
>>>>>>>>> > > > > 34 packets transmitted, 28 received, 17.6471% packet loss,
>>>>>>>>> time 3328ms
>>>>>>>>> > > > >
>>>>>>>>> > > > > rtt min/avg/max/mdev = 1.396/6.266/9.590/2.805 ms
>>>>>>>>> > > > >
>>>>>>>>> > > > >
>>>>>>>>> > > > >
>>>>>>>>> > > > > Does any one get this issue ?
>>>>>>>>> > > > >
>>>>>>>>> > > > > Please help me. Thanks
>>>>>>>>> > > > >
>>>>>>>>> > > >
>>>>>>>>>
>>>>>>>>>
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