Open Stack

Hi Kevin,

Thanks for your response...

On 08/05/15 08:43, Kevin Benton wrote:
> I'm not sure I understand the behavior you are seeing. When your
> mechanism driver gets initialized and kicks off processing, all of that
> should be happening in the parent PID. I don't know why your child
> processes start executing code that wasn't invoked. Can you provide a
> pointer to the code or give a sample that reproduces the issue?

https://github.com/Metaswitch/calico/tree/master/calico/openstack

Basically, our driver's initialize method immediately kicks off a green 
thread to audit what is now in the Neutron DB, and to ensure that the 
other Calico components are consistent with that.

> I modified the linuxbridge mech driver to try to reproduce it:
> http://paste.openstack.org/show/216859/
>
> In the output, I never received any of the init code output I added more
> than once, including the function spawned using eventlet.

Interesting.  Even the LOG.error("KEVIN PID=%s network response: %s" % 
(os.getpid(), r.text)) line?  Surely the server would have forked before 
that line was executed - so what could prevent it from executing once in 
each forked process, and hence generating multiple logs?

Thanks,
	Neil

> The only time I ever saw anything executed by a child process was actual
> API requests (e.g. the create_port method).



> On Thu, May 7, 2015 at 6:08 AM, Neil Jerram <Neil.Jerram at metaswitch.com
> <mailto:Neil.Jerram at metaswitch.com>> wrote:
>
>     Is there a design for how ML2 mechanism drivers are supposed to cope
>     with the Neutron server forking?
>
>     What I'm currently seeing, with api_workers = 2, is:
>
>     - my mechanism driver gets instantiated and initialized, and
>     immediately kicks off some processing that involves communicating
>     over the network
>
>     - the Neutron server process then forks into multiple copies
>
>     - multiple copies of my driver's network processing then continue,
>     and interfere badly with each other :-)
>
>     I think what I should do is:
>
>     - wait until any forking has happened
>
>     - then decide (somehow) which mechanism driver is going to kick off
>     that processing, and do that.
>
>     But how can a mechanism driver know when the Neutron server forking
>     has happened?
>
>     Thanks,
>              Neil
>
>     __________________________________________________________________________
>     OpenStack Development Mailing List (not for usage questions)
>     Unsubscribe:
>     OpenStack-dev-request at lists.openstack.org?subject:unsubscribe
>     <http://OpenStack-dev-request@lists.openstack.org?subject:unsubscribe>
>     http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
>
>
>
>
> --
> Kevin Benton
>
>
> __________________________________________________________________________
> OpenStack Development Mailing List (not for usage questions)
> Unsubscribe: OpenStack-dev-request at lists.openstack.org?subject:unsubscribe
> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
>