Open Stack

When you say trunk issue do you mean about the RPC calls going to
uWSGI threads or this general issue with long times.  For the long
times I'm not sure I have enough detail to write a bug but I could for
the RPC calls.

Also I'm using LinuxBridge on the backend.

Thanks, john

On 4/4/23, Lajos Katona <katonalala at gmail.com> wrote:
> 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
>>
>>
>