[ovs-dev] [ovn-controller-vtep V3 2/7] ovn-sb: Remove the "Gateway" table from the ovn-sb schema.

[Ben Pfaff]

On Wed, Jul 15, 2015 at 09:40:08PM -0700, Alex Wang wrote:
> On Wed, Jul 15, 2015 at 1:10 PM, Ben Pfaff <blp at nicira.com> wrote:
> 
> > On Mon, Jul 13, 2015 at 08:22:38PM -0700, Alex Wang wrote:
> > > In a gateway like the VTEP L2 gateway, physical vlans belonging to
> > > the same logical network form a "logical switch".  Each logical switch
> > > has a dedicated tunnel key and will keep records of all MACs learned
> > > from the owned vlans.  So user can just send packet to a "logical
> > > switch" and the gateway will figure out the output port and vlan tag
> > > automatically.
> > >
> > > Therefore, it is not really necessary to keep record of the vlan map
> > > for each gateway physical port in the OVN_Southbound database using
> > > "gateway_ports".
> > >
> > > Thusly, this commit removes the "Gateway" table from the OVN_Southbound
> > > database.  In the "Chassis" table, the "gateway_ports" column is replaced
> > > by "logical_switches" column which maps the logical switch name in the
> > > gateway to a logical port name that exists in the OVN_Northbound
> > database's
> > > "Logical_Port" table.
> > >
> > > Signed-off-by: Alex Wang <alexw at nicira.com>
> > >
> > > ---
> > > ->V3:
> > > - Realize that the Gateway table is not needed.
> >
> > I think that the documentation can be improved.
> >
> > I ended up with this:
> >
> >     <group title="Gateway Configuration">
> >       <p>
> >         A <dfn>gateway</dfn> is a chassis that forwards traffic between the
> >         OVN-managed part of a logical network and a physical VLAN,
> > extending a
> >         tunnel-based logical network into a physical network.  Gateways are
> >         typically dedicated nodes that do not host VMs.
> >       </p>
> >
> >       <column name="logical_switches">
> >         Maps from the name of a logical switch on the gateway to a logical
> > port
> >         name.  The logical port name must be unique; one way to do this is
> > by
> >         concatenating the chassis name and the logical switch name.  User
> > needs
> >         to create a same named logical port in the OVN_Northbound
> > database's
> >         Logical_Port table.
> >       </column>
> >     </group>
> >
> > but I still have some issues with it.  First, I deleted this sentence
> > because I didn't understand it, but if you can explain then maybe
> > rephrasing it would be a better option:
> >
> >     Physical VLANs belonging to the one logical network form a
> >     <dfn>logical switch</dfn> in the <dfn>gateway</dfn>.
> 
> 
> >
> Second, the documentation says that the "user" needs to create the
> > logical port.  I'm not sure who the user is in this case.
> >
> 
> Here I'm trying to give a definition of what is a 'logical switch' in vtep,
> to help
> readers understand why the column is named 'logical_switches'.  I think I'll
> change the column name to "vtep_logical_switches" and so maybe readers
> could refer to the vtep schema manual.
> 
> For the second point, the 'user' should be the CMS~
> 
> how about this:
> 
> """
> <column name="vtep_logical_switches">
> Maps from the name of a vtep logical switch on the gateway to a logical port
> name.  The logical port name must be unique; one way to do this is by
> concatenating the chassis name and the logical switch name.  To include
> one vtep logical switch to an OVN logical network, a same named logical
> port should be created in the Logical_Port table and be attached to some
> Logical_Switch in the OVN_Northbound database.
> </column>
> """

That's better, but I prefer to say explicitly the actor that should
create the logical port, because it makes it clearer to readers than
just saying that it should happen.

Acked-by: Ben Pfaff <blp at nicira.com>