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Hi,
could you open a bug report on https://bugs.launchpad.net/neutron/ for the
trunk issue with reproduction steps?
It is also important which backend you use? OVS or something else?

Thanks in advance
Lajos Katona (lajoskatona)

John Bartelme <bartelme at gmail.com> ezt írta (időpont: 2023. ápr. 4., K,
14:15):

> Hello,
>
> I'm currently experiencing some pretty severe performance issues with my
> openstack-ansible deployed cluster(yoga) while deploying trunk ports and
> I'm looking for some help determining what might be the cause of this poor
> performance.
>
> In my simplest case I'm deploying 2 servers each with one trunk port each.
> The first trunk has 2 subports and the second 6 subports. Both servers also
> have 3 other regular ports. When deploying the first trunk port its
> subports are often provisioned quickly and the second trunk port takes
> anywhere from 30 seconds to 18 minutes. This happens even when I isolate
> neutron-server to a single physical machine with 44(88 threads) and 256GB
> ram. Further diagnosis has shown me some things i didn't quite understand.
> My deployment with OpenStack-ansible deploys neutron-server with 16 uWSGI
> processes and neutron-rpc-server with 16 rpc workers. However the way that
> the trunk RPC server is implemented it is only run on the parent RPC thread
> and instead runs in all of the uWSGI processes as well. This means that
> most of my trunk RPC calls are being handled by the uWSGI instead of the
> RPC workers. When the parent RPC thread handles the trunk port creation
> calls I constantly see creation times of 1-1.5 seconds. I've isolated it so
> that this thread does all of the trunk RPC calls and this works quite well
> but this doesn't seem ideal. What could be causing such poor performance in
> the uWSGI side of the house? I'm having a really hard time getting a good
> feeling for what might be slowing it down so much. I'm wondering if it
> could be green thread preemption but I really don't know. I've tried
> setting 'enable-threads' false for uWSGI but I don't think that is
> improving performance. Putting the profiled decorator on
> update_subport_bindings shows different places taking longer every time,
> but in general a lot of time(tottime, i.e. not subfunction time) spent in
> webob/dec.py(__call__), paste/urlmap.py(__call__),
> webob/request.py(call_application),webob/request.py(send). What else can I
> do to try and look for why this is taking so long?
>
> As a side question it seems counterintuitive that the uWSGI handles most of
> the trunk RPC calls and not the RPC workers?
>
> A couple other notes about my environment that could indicate my
> challenges:
>
> I had to disable rabbitmq heartbeats for neutron as they kept not getting
> sent reliably and connections were terminated. I tried with
> heartbeat_in_pthread both true and false but still had issues. It looks
> like nova also sometimes experiences this but not near as often.
>
> I was overzealous with my vxlan ranges in my first configuration and gave
> it a range of 10,000,000 not realizing that would create that many rows in
> the database. Looking into that I saw that pymysql in my cluster takes 3.5
> minutes to retrieve those rows. mysql CLI only takes 4 seconds. Perhaps
> that is just the overhead of pymysql? I've greatly scaled down the vxlan
> range now.
>
> I'm provisioning the 2 servers with a heat template that contains around
> 200 custom resources. For 198 of the resources they are set to
> conditionally not create any OpenStack native resources. Deploying this
> template of mostly no-op resources still takes about 3 minutes.
>
> Horizon works but almost every page load take a few seconds to load. I'm
> not sure if that is normal or not.
>
> Thanks for any help anyone can provide.
>
> john
>
>
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