OpenStack Quantum integration feature page for 3.3

Tue Apr 9 08:01:01 UTC 2013

----- Original Message -----
> On 04/09/2013 10:16 AM, Mike Kolesnik wrote:
> > ----- Original Message -----
> >> On 04/08/2013 07:13 PM, Dan Kenigsberg wrote:
> >>> On Fri, Mar 22, 2013 at 08:34:14AM +0200, Gary Kotton wrote:
> >>>> On 03/21/2013 11:06 PM, Dan Kenigsberg wrote:
> >>>>> On Thu, Mar 21, 2013 at 03:53:38PM +0200, Gary Kotton wrote:
> >>>>>> On 03/21/2013 03:12 PM, Dan Kenigsberg wrote:
> >>>>>>> On Mon, Mar 18, 2013 at 04:23:32AM -0400, Mike Kolesnik wrote:
> >>>>>>>> ----- Original Message -----
> >>>>>>>>> On Mon, Mar 18, 2013 at 03:20:45AM -0400, Mike Kolesnik wrote:
> >>>>>>>>>> Hi all,
> >>>>>>>>>>
> >>>>>>>>>> The feature page for integrating OpenStack Quantum into oVirt is
> >>>>>>>>>> available on the wiki:
> >>>>>>>>>> http://www.ovirt.org/Features/Quantum_Integration
> >>>>>>>>>>
> >>>>>>>>> A quote from "Network discovery":
> >>>>>>>>>> Currently, we assume that the networks provided by the provider
> >>>>>>>>>> are
> >>>>>>>>>> available on all hosts in the data center...
> >>>>>>>>> it is not completely clear who are "we" there. I suppose that you
> >>>>>>>>> mean
> >>>>>>>>> that Engine takes this assumption, and does not verify that a
> >>>>>>>>> specific
> >>>>>>>>> host is actually connectable by the network provider. That's not
> >>>>>>>>> much
> >>>>>>>>> worse than what Engine does elsewhere: it does not verify that
> >>>>>>>>> network
> >>>>>>>>> "green" in one host can actually connect with network "green" on
> >>>>>>>>> another
> >>>>>>>>> host.
> >>>>>>>> "We" is oVirt as a whole.
> >>>>>>>>
> >>>>>>>> Currently we do know which network is available on which host since
> >>>>>>>> the user set it up.
> >>>>>>>> In the planned integration we wouldn't know, thus we will consider
> >>>>>>>> external network as "provided".
> >>>>>>> So *Engine* cannot tell if a host is controllable by the defined
> >>>>>>> quantum
> >>>>>>> server, and therefore it has to assume that everything is all right,
> >>>>>>> putting this burden on the end user.
> >>>>>>>
> >>>>>>> Garry, does Quantum provide any means to tell - ahead of time - if
> >>>>>>> provisioning a virtual network to a specific work is expected to
> >>>>>>> succeed? Or, let's say, that the host is utterly misconfigured and is
> >>>>>>> unknown to Quantum? Can it at least be done for plugins with host
> >>>>>>> agents?
> >>>>>> I am not really sure that I understand your question. Can you please
> >>>>>> clarify what you mean by "if provisioning a virtual network ... is
> >>>>>> expected to succeed".
> >>>>>>
> >>>>>> Lets take two open source examples:
> >>>>>> openvswitch - a integration bridge is provisioned ahed of time, that
> >>>>>> is, each host will need to provision an integration bridge on the
> >>>>>> OVS. When the agent detects that new port is created on the bridge
> >>>>>> then it will configure the relevant VLAN. The Quantum service will
> >>>>>> be notified that the port is "UP"
> >>>>>> linuxbridge - the nova host that is deplying the VM will create the
> >>>>>> networkwork if it does not exist. If this fails the a VM will not be
> >>>>>> spawned. Once the network is up the agent will configure the VLAN.
> >>>>>> The quantum service will be notified that the port is "UP"
> >>>>>>
> >>>>>> The assumption is that the hosts will be configured correctly. If
> >>>>> I would like to have a clue - ahead of time - if that assumption is
> >>>>> valid. The two examples above require the host to notify the Quantum
> >>>>> service. But what if the host agent is notifying an utterly different
> >>>>> service? Is there some kind of liveliness check between the host and
> >>>>> its
> >>>>> Quantum service?
> >>>> The communication between the host and the quantum service is done
> >>>> by a message broker. If the host is updating a different service
> >>>> then the port state will not be set as "UP"
> >>>> In grizzy a feature was added where one is able to get the state of
> >>>> the agents for example:
> >>>>
> >>>> openstack at dhcp-4-227:~/devstack$ quantum agent-list
> >>>> +--------------------------------------+--------------------+---------------------------+-------+----------------+
> >>>> | id                                   | agent_type         | host
> >>>> | alive | admin_state_up |
> >>>> +--------------------------------------+--------------------+---------------------------+-------+----------------+
> >>>> | 1ab54438-9338-4050-a818-7faf28d31eb2 | DHCP agent         |
> >>>> dhcp-4-227.tlv.redhat.com | :-)   | True           |
> >>>> | 396f03eb-b3af-4ddf-b52f-6a0de65b0574 | L3 agent           |
> >>>> dhcp-4-227.tlv.redhat.com | :-)   | True           |
> >>>> | 876c7474-9e2e-4533-a27e-1de8ac3544c6 | Open vSwitch agent |
> >>>> dhcp-4-227.tlv.redhat.com | :-)   | True           |
> >>>> +--------------------------------------+--------------------+---------------------------+-------+----------------+
> >>>>
> >>>> If you get an XXX instead of a :) then the agent is down. The above
> >>>> is used for scheduling networks and routers to the dhcp and l3
> >>>> agents respectively.
> >>>>
> >>>> Does this help?
> >>> Yes. It seems that this is done at the Quantum server. Is it exposed by
> >>> the Quantum API or an extension thereof?
> >> This is exposed by a Quantum extension. It is not part of the official
> >> API and may not be supported by some plugins.
> >> You are nonetheless able to query which extensions are supported by the
> >> plugin.
> >>
> >>> This information is valuable for scheduling VMs, and I'd like to
> >>> understand how oVirt can tap into it.
> >> If the above extension is supported and the agent on the host is down
> >> then the scheduler should exclude that host - if that host is selected
> >> then the VM will not have network connectivity.
> >>
> >>> Also, what happens with agent-less plugins? Can Quantum tell who are the
> >>> hosts that it controls?
> >> This depends on the extensions supported by the plugin.
> >>
> >> At the moment there is a patch in progress (Havana) which will have the
> >> extension for the port bindings store the host. Once again this may not
> >> be supported by some plugins.
> > Do you know if it will be supported for Linux Bridge&  OVS plugins?
> 
> Yes, this is currently supported by these plugins.
> 

Is there an API reference that you can please provide that documents this extension?

> 
> 