[ovs-dev] [PATCH ovn] ovn-northd: Optionally skip the check of lsp_is_up.

Han Zhou hzhou at ovn.org
Tue Sep 8 18:27:00 UTC 2020


On Tue, Sep 8, 2020 at 5:29 AM Numan Siddique <numans at ovn.org> wrote:
>
> On Thu, Sep 3, 2020 at 7:44 AM Han Zhou <hzhou at ovn.org> wrote:
> >
> > The checking of lsp "up" status before adding ARP responder flows was
> > added to avoid confusion in cases when a network admin sees ARP response
> > for VM/containers that is not up on chassis yet. However, this check
> > introduces an extra round of flow change in SB and triggers computes
> > on hypervisors which is unnecessary cost in most cases, especially for
> > large scale environment. To improve this, this patch provides an option
> > check_lsp_is_up to disable the check (when setting to "false") for the
> > use cases when ARP reponse for a port that is "down" isn't considered
> > harmful.
> >
> > Signed-off-by: Han Zhou <hzhou at ovn.org>
>
>
> Few minor comments.
>
> Acked-by: Numan Siddique <numans at ovn.org> with those addressed.
>
> Thanks
> Numan
>
> > ---
> >  northd/ovn-northd.8.xml | 15 ++++++++++-----
> >  northd/ovn-northd.c     |  7 ++++++-
> >  ovn-nb.xml              | 18 ++++++++++++++++++
> >  tests/ovn-northd.at     | 14 ++++++++++++++
> >  4 files changed, 48 insertions(+), 6 deletions(-)
> >
> > diff --git a/northd/ovn-northd.8.xml b/northd/ovn-northd.8.xml
> > index 989e364..df43eb6 100644
> > --- a/northd/ovn-northd.8.xml
> > +++ b/northd/ovn-northd.8.xml
> > @@ -763,9 +763,11 @@ output;
> >
> >          <p>
> >            These flows are omitted for logical ports (other than router
ports or
> > -          <code>localport</code> ports) that are down, for logical
ports of
> > -          type <code>virtual</code> and for logical ports with
'unknown'
> > -          address set.
> > +          <code>localport</code> ports) that are down (unless <code>
> > +          check_lsp_is_up</code> is configured as false in
<code>options</code>
> > +          column of <code>NB_Global</code> table of the
<code>Northbound</code>
> > +          database), for logical ports of type <code>virtual</code>
and for
> > +          logical ports with 'unknown' address set.
> >          </p>
> >        </li>
> >
> > @@ -812,8 +814,11 @@ nd_na_router {
> >
> >          <p>
> >            These flows are omitted for logical ports (other than router
ports or
> > -          <code>localport</code> ports) that are down and for logical
ports of
> > -          type <code>virtual</code>.
> > +          <code>localport</code> ports) that are down (unless <code>
> > +          check_lsp_is_up</code> is configured as false in
<code>options</code>
> > +          column of <code>NB_Global</code> table of the
<code>Northbound</code>
> > +          database), for logical ports of type <code>virtual</code>
and for
> > +          logical ports with 'unknown' address set.
> >          </p>
> >        </li>
> >
> > diff --git a/northd/ovn-northd.c b/northd/ovn-northd.c
> > index 7be0e85..291713e 100644
> > --- a/northd/ovn-northd.c
> > +++ b/northd/ovn-northd.c
> > @@ -86,6 +86,8 @@ static struct eth_addr mac_prefix;
> >
> >  static bool controller_event_en;
> >
> > +static bool check_lsp_is_up;
> > +
> >  /* MAC allocated for service monitor usage. Just one mac is allocated
> >   * for this purpose and ovn-controller's on each chassis will make use
> >   * of this mac when sending out the packets to monitor the services
> > @@ -6739,7 +6741,8 @@ build_lswitch_flows(struct hmap *datapaths,
struct hmap *ports,
> >               *  - port type is router or
> >               *  - port type is localport
> >               */
> > -            if (!lsp_is_up(op->nbsp) && strcmp(op->nbsp->type,
"router") &&
> > +            if (check_lsp_is_up &&
> > +                !lsp_is_up(op->nbsp) && strcmp(op->nbsp->type,
"router") &&
> >                  strcmp(op->nbsp->type, "localport")) {
> >                  continue;
> >              }
> > @@ -11722,6 +11725,8 @@ ovnnb_db_run(struct northd_context *ctx,
> >
> >      controller_event_en = smap_get_bool(&nb->options,
> >                                          "controller_event", false);
> > +    check_lsp_is_up = smap_get_bool(&nb->options,
> > +                                    "check_lsp_is_up", true);
> >
> >      build_datapaths(ctx, datapaths, lr_list);
> >      build_ports(ctx, sbrec_chassis_by_name, datapaths, ports);
> > diff --git a/ovn-nb.xml b/ovn-nb.xml
> > index 1f2dbb9..4e34518 100644
> > --- a/ovn-nb.xml
> > +++ b/ovn-nb.xml
> > @@ -147,6 +147,24 @@
> >          </p>
> >        </column>
> >
> > +      <column name="options" key="check_lsp_is_up">
>
> How about "ignore_lport_down" ? The default would be false. If you're
> fine with this, then
> you need to invert the logic in the code.
>
Thanks Numan for the suggestion. Yes, this sounds better. And since in
ovn-nbctl we use lsp to denote a logical switch port, maybe
"ignore_lsp_down" is better?
I will send a v2 for this.

> I don't have a very strong opinion. If you want to stick with
> check_lsp_is_up, I'm fine with it.
>
>
> > +        <p>
> > +          If set to true, ARP/ND reply flows for logical switch ports
will be
> > +          installed only if the port is up, i.e. claimed by a Chassis.
If set
> > +          to false, these flows are installed regardless of the status
of the
> > +          port, which can result in a situation that ARP request to an
IP is
> > +          resolved even before the relevant VM/container is running.
For
> > +          environments where this is not an issue, setting it to
> > +          <code>false</code> can reduce the load and latency of the
control
> > +          plane. The default value is <code>true</code>.
> > +        </p>
> > +
> > +        <p>
> > +          If the value is nonzero, then it will be forced to a value of
> > +          at least 1000 ms.
> > +        </p>
>
> Looks like some copy/paste issue ? Because the value is a boolean :).
>
Oops. Thanks for catching it.

> Thanks
> Numan
>
>
>
> > +      </column>
> > +
> >        <group title="Options for configuring interconnection route
advertisement">
> >          <p>
> >            These options control how routes are advertised between OVN
> > diff --git a/tests/ovn-northd.at b/tests/ovn-northd.at
> > index 8344c7f..c98df49 100644
> > --- a/tests/ovn-northd.at
> > +++ b/tests/ovn-northd.at
> > @@ -1781,3 +1781,17 @@ AT_CHECK([ovn-sbctl lflow-list | grep
"ls_out_pre_lb.*priority=100" | grep reg0
> >  ])
> >
> >  AT_CLEANUP
> > +
> > +AT_SETUP([ovn -- disable check_lsp_is_up])
> > +ovn_start
> > +
> > +ovn-nbctl ls-add sw0
> > +ovn-nbctl lsp-add sw0 sw0-p1 -- lsp-set-addresses sw0-p1
"aa:aa:aa:aa:aa:aa 10.0.0.1"
> > +
> > +ovn-nbctl --wait=sb sync
> > +AT_CHECK([ovn-sbctl lflow-list | grep arp | grep 10\.0\.0\.1], [1],
[ignore])
> > +
> > +ovn-nbctl --wait=sb set NB_Global . options:check_lsp_is_up=false
> > +AT_CHECK([ovn-sbctl lflow-list | grep arp | grep 10\.0\.0\.1], [0],
[ignore])
>
> > +
> > +AT_CLEANUP
> > --
> > 2.1.0
> >
> > _______________________________________________
> > dev mailing list
> > dev at openvswitch.org
> > https://mail.openvswitch.org/mailman/listinfo/ovs-dev
> >


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