<div dir="ltr"><div class="gmail_extra"><div><div class="gmail_signature"><div dir="ltr"><br></div></div></div><div class="gmail_quote">On Wed, Feb 25, 2015 at 5:34 AM, Sukhdev Kapur <span dir="ltr"><<a href="mailto:sukhdevkapur@gmail.com" target="_blank">sukhdevkapur@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Folks, <div><br></div><div>A great discussion. I am not expert at OVN, hence, want to ask a question. The answer may make a  case that it should probably be a ML2 driver as oppose to monolithic plugin. </div><div><br></div><div>Say a customer want to deploy an OVN based solution and use HW devices from one vendor for L2 and L3 (e.g. Arista or Cisco), and want to use another vendor for services (e.g. F5 or A10) - how can that be supported? </div><div><br></div><div>If OVN goes in as ML2 driver, I can then run ML2 and Service plugin to achieve above solution. For a monolithic plugin, don't I have an issue? </div></div></blockquote><div>On the specifics of service plugins: service plugins and standalone plugins can co-exist to provide a solution with advanced services from different vendors. Some existing monolithic plugins (e.g. PLUMgrid) have blueprints deployed using this approach. </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><br></div><div>regards..</div><span class="HOEnZb"><font color="#888888"><div>-Sukhdev</div><div><br></div></font></span></div><div class="HOEnZb"><div class="h5"><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Feb 24, 2015 at 8:58 AM, Salvatore Orlando <span dir="ltr"><<a href="mailto:sorlando@nicira.com" target="_blank">sorlando@nicira.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">I think we're speculating a lot about what would be best for OVN whereas we should probably just expose pro and cons of ML2 drivers vs standalone plugin (as I said earlier on indeed it does not necessarily imply monolithic *)<div><br></div><div>I reckon the job of the Neutron community is to provide a full picture to OVN developers - so that they could make a call on the integration strategy that best suits them.</div><div>On the other hand, if we're planning to commit to a model where ML2 is not anymore a plugin but the interface with the API layer, then any choice which is not a ML2 driver does not make any sense. Personally I'm not sure we ever want to do that, at least not in the near/medium term, but I'm one and hardly representative of the developer/operator communities.</div><div><br></div><div>Salvatore<br><div><br></div><div><br></div><div>* In particular with the advanced service split out the term monolithic simply does not mean anything anymore.</div></div></div><div><div><div class="gmail_extra"><br><div class="gmail_quote">On 24 February 2015 at 17:48, Robert Kukura <span dir="ltr"><<a href="mailto:kukura@noironetworks.com" target="_blank">kukura@noironetworks.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
  
    
  
  <div text="#000000" bgcolor="#FFFFFF">
    Kyle, What happened to the long-term potential goal of ML2 driver
    APIs becoming neutron's core APIs? Do we really want to encourage
    new monolithic plugins?<br>
    <br>
    ML2 is not a control plane - its really just an integration point
    for control planes. Although co-existence of multiple mechanism
    drivers is possible, and sometimes very useful, the single-driver
    case is fully supported. Even with hierarchical bindings, its not
    really ML2 that controls what happens - its the drivers within the
    framework. I don't think ML2 really limits what drivers can do, as
    long as a virtual network can be described as a set of static and
    possibly dynamic network segments. ML2 is intended to impose as few
    constraints on drivers as possible.<br>
    <br>
    My recommendation would be to implement an ML2 mechanism driver for
    OVN, along with any needed new type drivers or extension drivers. I
    believe this will result in a lot less new code to write and
    maintain.<br>
    <br>
    Also, keep in mind that even if multiple driver co-existence doesn't
    sound immediately useful, there are several potential use cases to
    consider. One is that it allows new technology to be introduced into
    an existing cloud alongside what previously existed. Migration from
    one ML2 driver to another may be a lot simpler (and/or flexible)
    than migration from one plugin to another. Another is that
    additional drivers can support special cases, such as bare metal,
    appliances, etc..<br>
    <br>
    -Bob<div><div><br>
    <br>
    <div>On 2/24/15 11:11 AM, Kyle Mestery
      wrote:<br>
    </div>
    <blockquote type="cite">
      <div dir="ltr">
        <div class="gmail_extra">
          <div class="gmail_quote">On Tue, Feb 24, 2015 at 3:19 AM,
            Salvatore Orlando <span dir="ltr"><<a href="mailto:sorlando@nicira.com" target="_blank">sorlando@nicira.com</a>></span>
            wrote:<br>
            <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
              <div dir="ltr">
                <div class="gmail_extra">
                  <div class="gmail_quote"><span>On 24 February
                      2015 at 01:34, Kyle Mestery <span dir="ltr"><<a href="mailto:mestery@mestery.com" target="_blank">mestery@mestery.com</a>></span>
                      wrote:<br>
                      <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
                        <div dir="ltr">
                          <div>
                            <div>Russel and I have already merged the
                              initial ML2 skeleton driver [1].</div>
                          </div>
                        </div>
                      </blockquote>
                      <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
                        <div dir="ltr">
                          <div>
                            <div>The thinking is that we can always
                              revert to a non-ML2 driver if needed. </div>
                          </div>
                        </div>
                      </blockquote>
                      <div><br>
                      </div>
                    </span>
                    <div>If nothing else an authoritative decision on a
                      design direction saves us the hassle of going
                      through iterations and discussions.</div>
                    <div>The integration through ML2 is definitely
                      viable. My opinion however is that since OVN
                      implements a full control plane, the control plane
                      bits provided by ML2 are not necessary, and a
                      plugin which provides only management layer
                      capabilities might be the best solution. Note:
                      this does not mean it has to be monolithic. We can
                      still do L3 with a service plugin.<br>
                    </div>
                    <div>However, since the same kind of approach has
                      been adopted for ODL I guess this provides some
                      sort of validation.</div>
                    <span>
                      <div> <br>
                      </div>
                    </span></div>
                </div>
              </div>
            </blockquote>
            <div>To be honest, after thinking about this last night, I'm
              now leaning towards doing this as a full plugin. I don't
              really envision OVN running with other plugins, as OVN is
              implementing it's own control plane, as you say. So the
              value of using ML2 is quesitonable.<br>
               <br>
            </div>
            <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
              <div dir="ltr">
                <div class="gmail_extra">
                  <div class="gmail_quote"><span>
                      <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
                        <div dir="ltr">
                          <div>
                            <div>I'm not sure how useful having using
                              OVN with other drivers will be, and that
                              was my initial concern with doing ML2 vs.
                              full plugin. With the HW VTEP support in
                              OVN+OVS, you can tie in physical devices
                              this way. Anyways, this is where we're at
                              for now. Comments welcome, of course.<br>
                            </div>
                          </div>
                        </div>
                      </blockquote>
                      <div><br>
                      </div>
                    </span>
                    <div>That was also kind of my point regarding the
                      control plane bits provided by ML2 which OVN does
                      not need. Still, the fact that we do not use a
                      function does not make any harm. </div>
                    <div>Also i'm not sure if OVN needs at all a type
                      manager. If not, we can always implement a no-op
                      type manager, I guess.</div>
                    <span><font color="#888888">
                        <div><br>
                        </div>
                      </font></span></div>
                </div>
              </div>
            </blockquote>
            <div>See above. I'd like to propose we move OVN to a full
              plugin instead of an ML2 MechanismDriver.<br>
              <br>
            </div>
            <div>Kyle<br>
               <br>
            </div>
            <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
              <div dir="ltr">
                <div class="gmail_extra">
                  <div class="gmail_quote"><span><font color="#888888">
                        <div>Salvatore</div>
                      </font></span>
                    <div>
                      <div>
                        <div> </div>
                        <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
                          <div dir="ltr">
                            <div>
                              <div><br>
                              </div>
                              Thanks,<br>
                            </div>
                            Kyle<br>
                            <br>
                            [1] <a href="https://github.com/stackforge/networking-ovn" target="_blank">https://github.com/stackforge/networking-ovn</a><br>
                          </div>
                          <div>
                            <div>
                              <div class="gmail_extra"><br>
                                <div class="gmail_quote">On Mon, Feb 23,
                                  2015 at 4:09 PM, Kevin Benton <span dir="ltr"><<a href="mailto:blak111@gmail.com" target="_blank">blak111@gmail.com</a>></span>
                                  wrote:<br>
                                  <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
                                    <div dir="ltr">I want to emphasize
                                      Salvatore's last two points a bit
                                      more. If you go with a monolithic
                                      plugin, you eliminate the
                                      possibility of heterogenous
                                      deployments. 
                                      <div><br>
                                      </div>
                                      <div>One example of this that is
                                        common now is having the current
                                        OVS driver responsible for
                                        setting up the vswitch and then
                                        having a ToR driver (e.g. Big
                                        Switch, Arista, etc) responsible
                                        for setting up the fabric.
                                        Additionally, there is a
                                        separate L3 plugin (e.g. the
                                        reference one, Vyatta, etc) for
                                        providing routing.
                                        <div><br>
                                        </div>
                                        <div>I suppose with an overlay
                                          it's easier to take the route
                                          that you don't want to be
                                          compatible with other
                                          networking stuff at the
                                          Neutron layer (e.g.
                                          integration with the 3rd
                                          parties is orchestrated
                                          somewhere else). In that case,
                                          the above scenario wouldn't
                                          make much sense to support,
                                          but it's worth keeping in
                                          mind.</div>
                                      </div>
                                    </div>
                                    <div class="gmail_extra">
                                      <div>
                                        <div><br>
                                          <div class="gmail_quote">On
                                            Mon, Feb 23, 2015 at 10:28
                                            AM, Salvatore Orlando <span dir="ltr"><<a href="mailto:sorlando@nicira.com" target="_blank">sorlando@nicira.com</a>></span>
                                            wrote:<br>
                                            <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
                                              <div dir="ltr">I think
                                                there are a few factors
                                                which influence the ML2
                                                driver vs "monolithic"
                                                plugin debate, and they
                                                mostly depend on OVN
                                                rather than Neutron.
                                                <div>From a Neutron
                                                  perspective both
                                                  plugins and drivers
                                                  (as long at they live
                                                  in their own tree)
                                                  will be supported in
                                                  the foreseeable
                                                  future. If a ML2 mech
                                                  driver is not the best
                                                  option for OVN that
                                                  would be ok - I don't
                                                  think the Neutron
                                                  community advices
                                                  development of a ML2
                                                  driver as the
                                                  preferred way for
                                                  integrating with new
                                                  backends.<br>
                                                </div>
                                                <div><br>
                                                </div>
                                                <div>The ML2 framework
                                                  provides a long list
                                                  of benefits that
                                                  mechanism driver
                                                  developer can
                                                  leverage.</div>
                                                <div>Among those:</div>
                                                <div>- The ability of
                                                  leveraging Type
                                                  drivers which relieves
                                                  driver developers from
                                                  dealing with network
                                                  segment allocation</div>
                                                <div>- Post-commit and
                                                  (for most operations)
                                                  pre-commit hooks for
                                                  performing operation
                                                  on the backend</div>
                                                <div>- The ability to
                                                  leverage some of the
                                                  features offered by
                                                  Neutron's built-in
                                                  control-plane such as
                                                  L2-population</div>
                                                <div>- A flexible
                                                  mechanism for enabling
                                                  driver-specific API
                                                  extensions</div>
                                                <div>- Promotes modular
                                                  development and
                                                  integration with
                                                  higher-layer services,
                                                  such as L3. For
                                                  instance OVN could
                                                  provide the L2 support
                                                  for Neutron's built-in
                                                  L3 control plane</div>
                                                <div>- The (potential
                                                  afaict) ability of
                                                  interacting with other
                                                  mechanism driver such
                                                  as those operating on
                                                  physical appliances on
                                                  the data center</div>
                                                <div>- <add your
                                                  benefit here></div>
                                                <div><br>
                                                </div>
                                                <div>In my opinion OVN
                                                  developers should look
                                                  at ML2 benefits, and
                                                  check which ones apply
                                                  to this specific
                                                  platform. I'd say that
                                                  if there are 1 or 2
                                                  checks in the above
                                                  list, maybe it would
                                                  be the case to look at
                                                  developing a ML2
                                                  mechanism driver, and
                                                  perhaps a L3 service
                                                  plugin.</div>
                                                <div>It is worth nothing
                                                  that ML2, thanks to
                                                  its type and mechanism
                                                  driver provides also
                                                  some control plane
                                                  capabilities. If those
                                                  capabilities are
                                                  however on OVN's
                                                  roadmap it might be
                                                  instead worth looking
                                                  at a "monolithic"
                                                  plugin, which can also
                                                  be easily implemented
                                                  by inheriting from
                                                  neutron.db.db_base_plugin_v2.NeutronDbPluginV2,
                                                  and then adding all
                                                  the python mixins for
                                                  the extensions the
                                                  plugin needs to
                                                  support.<span><font color="#888888"><br>
                                                    </font></span></div>
                                                <span><font color="#888888">
                                                    <div><br>
                                                    </div>
                                                    <div>Salvatore<br>
                                                    </div>
                                                  </font></span>
                                                <div>
                                                  <div>
                                                    <div><br>
                                                      <div>
                                                        <div class="gmail_extra"><br>
                                                          <div class="gmail_quote">On
                                                          23 February
                                                          2015 at 18:32,
                                                          Ben Pfaff <span dir="ltr"><<a href="mailto:blp@nicira.com" target="_blank">blp@nicira.com</a>></span>
                                                          wrote:<br>
                                                          <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">[branching
                                                          off a
                                                          discussion on
                                                          ovs-dev at
                                                          this point:<br>
                                                          <a href="http://openvswitch.org/pipermail/dev/2015-February/051609.html" target="_blank">http://openvswitch.org/pipermail/dev/2015-February/051609.html</a>]<br>
                                                          <br>
                                                          On Fri, Feb
                                                          20, 2015 at
                                                          6:56 PM, Kyle
                                                          Mestery <<a href="mailto:mestery@mestery.com" target="_blank">mestery@mestery.com</a>>
                                                          wrote:<br>
                                                          > One thing
                                                          to keep in
                                                          mind, this
                                                          ties somewhat
                                                          into my
                                                          response to
                                                          Russell<br>
                                                          > earlier
                                                          on the
                                                          decision
                                                          around ML2 vs.
                                                          core plugin.
                                                          If we do ML2,
                                                          there are<br>
                                                          > type
                                                          drivers for
                                                          VLAN, VXLAN,
                                                          and GRE
                                                          tunnels. There
                                                          is no
                                                          TypeDriver for<br>
                                                          > STT
                                                          tunnels
                                                          upstream now.
                                                          It's just an
                                                          item we need
                                                          on the TODO
                                                          list if we<br>
                                                          > go down
                                                          the STT tunnel
                                                          path.<br>
                                                          <br>
                                                          It was
                                                          suggested to
                                                          me off-list
                                                          that this part
                                                          of the
                                                          discussion
                                                          should be on<br>
                                                          openstack-dev,
                                                          so here it is
                                                          ;-)<br>
                                                          <br>
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                                                          </blockquote>
                                                          </div>
                                                          <br>
                                                        </div>
                                                      </div>
                                                    </div>
                                                  </div>
                                                </div>
                                              </div>
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                                              <br>
                                            </blockquote>
                                          </div>
                                          <br>
                                          <br clear="all">
                                          <div><br>
                                          </div>
                                        </div>
                                      </div>
                                      <span><font color="#888888">-- <br>
                                          <div>
                                            <div>Kevin Benton</div>
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              <br>
            </blockquote>
          </div>
          <br>
        </div>
      </div>
      <br>
      <fieldset></fieldset>
      <br>
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</pre>
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    <br>
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