On Thu, Aug 24, 2023 at 5:34 AM Jakub Libosvar <[email protected]> wrote: > > Hello, > > we use OpenStack (Neutron) as CMS and we have some customers reporting problems with their use case because of this change. I was wondering about the benefits described below in the commit message, are there any public data that back up the statements about the control plane cost at scale and latency? It would be great to have those to help with the decision whether we want to enable or disable this knob.
Hi Jakub, Thanks for reporting this. I am curious about the use case that is impacted by this behavior. Could you share more details? With regard to the control plane cost, I don't have data at hand, but it should be easy to test either with a scale test environment or with an actual deployment by enabling and disabling this setting and run the same test to compare. You should see obvious northd CPU time increase because for each LSP creation and binding there will be one more control plane round trip and recompute in northd, and if you check the ARP responder flow installation on the chassis, you should see its installation latency is much bigger. Of course, this depends on the scale under test which determines how long it takes for ovn-northd to recompute. Thanks, Han > > Thank you very much. > > Jakub > > > On Oct 2, 2021, at 3:11 AM, Han Zhou <[email protected]> wrote: > > > > The current default behavior is that ARP responder flows for VIFs are > > added by northd after the port-binding state is UP, which creates more > > trouble than benefit in most use cases. To make the default behavior > > desirable for majority of the use cases, set the option ignore_lsp_down > > to true by default. This would help saving the control plane cost in > > large scale environment, reduce the e2e latency for all flows to be > > installed for a VIF, and making the VIF readiness checking more convenient > > in test cases and likely in CMS as well. User can still set it to false > > in circumstances (if any) when this behavior is not desired. > > > > Signed-off-by: Han Zhou <[email protected]> > > --- > > NEWS | 4 ++++ > > northd/northd.c | 2 +- > > northd/ovn_northd.dl | 2 +- > > ovn-nb.xml | 2 +- > > tests/ovn-northd.at | 3 ++- > > 5 files changed, 9 insertions(+), 4 deletions(-) > > > > diff --git a/NEWS b/NEWS > > index 8a21c029e..348f3f548 100644 > > --- a/NEWS > > +++ b/NEWS > > @@ -12,6 +12,10 @@ OVN v21.09.0 - xx xxx xxxx > > - Allow static routes without nexthops. > > - Enabled logical dp groups as a default. CMS should disable it if not > > desired. > > + - Set ignore_lsp_down to true as default, so that ARP responder flows are > > + installed together with other flows when a logical switch port is created, > > + without having to wait for the port to be UP. CMS should set it to false > > + if not desired. > > > > OVN v21.06.0 - 18 Jun 2021 > > ------------------------- > > diff --git a/northd/northd.c b/northd/northd.c > > index cf2467fe1..5ffd6b8eb 100644 > > --- a/northd/northd.c > > +++ b/northd/northd.c > > @@ -14304,7 +14304,7 @@ 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, > > - "ignore_lsp_down", false); > > + "ignore_lsp_down", true); > > > > build_datapaths(ctx, datapaths, lr_list); > > build_ovn_lbs(ctx, datapaths, &lbs); > > diff --git a/northd/ovn_northd.dl b/northd/ovn_northd.dl > > index 22913f05a..7154fed13 100644 > > --- a/northd/ovn_northd.dl > > +++ b/northd/ovn_northd.dl > > @@ -753,7 +753,7 @@ Northd_Probe_Interval[interval] :- > > relation CheckLspIsUp[bool] > > CheckLspIsUp[check_lsp_is_up] :- > > nb in nb::NB_Global(), > > - var check_lsp_is_up = not nb.options.get_bool_def(i"ignore_lsp_down", false). > > + var check_lsp_is_up = not nb.options.get_bool_def(i"ignore_lsp_down", true). > > CheckLspIsUp[true] :- > > Unit(), > > not nb in nb::NB_Global(). > > diff --git a/ovn-nb.xml b/ovn-nb.xml > > index 390cc5a44..d8266ed4d 100644 > > --- a/ovn-nb.xml > > +++ b/ovn-nb.xml > > @@ -236,7 +236,7 @@ > > resolved even before the relevant VM/container is running. For > > environments where this is not an issue, setting it to > > <code>true</code> can reduce the load and latency of the control > > - plane. The default value is <code>false</code>. > > + plane. The default value is <code>true</code>. > > </p> > > </column> > > > > diff --git a/tests/ovn-northd.at b/tests/ovn-northd.at > > index c5400d806..3eebb55b6 100644 > > --- a/tests/ovn-northd.at > > +++ b/tests/ovn-northd.at > > @@ -1918,6 +1918,7 @@ OVN_FOR_EACH_NORTHD([ > > AT_SETUP([ignore_lsp_down]) > > ovn_start > > > > +ovn-nbctl set NB_Global . options:ignore_lsp_down=false > > 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" > > > > @@ -4922,7 +4923,7 @@ check ovn-nbctl lsp-add sw0 lsp0 \ > > > > check ovn-nbctl --wait=sb sync > > AT_CHECK([ovn-sbctl --columns=tags list logical_flow | grep lsp0 -c], [0], [dnl > > -9 > > +10 > > ]) > > > > AT_CLEANUP > > -- > > 2.30.2 > > > > _______________________________________________ > > dev mailing list > > [email protected] > > https://mail.openvswitch.org/mailman/listinfo/ovs-dev > > > _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
