[ovs-dev,2/2] OVN: northd: add rate limiting support for SB controller events

Introduce the capability to associate a meter to each controller event
type in order to not overload the pinctrl thread under heavy load.
Each event type relies on a meter with a defined name:
- empty_lb_backends: event-elb

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
---
 northd/ovn-northd.c | 44 +++++++++++++++++++++++++++++++++++---------
 ovn-nb.xml          |  8 ++++++++
 tests/ovn.at        |  1 +
 3 files changed, 44 insertions(+), 9 deletions(-)

Bleep bloop.  Greetings Lorenzo Bianconi, I am a robot and I have tried out your patch.
Thanks for your contribution.

I encountered some error that I wasn't expecting.  See the details below.


git-am:
fatal: sha1 information is lacking or useless (northd/ovn-northd.c).
Repository lacks necessary blobs to fall back on 3-way merge.
Cannot fall back to three-way merge.
Patch failed at 0001 OVN: northd: add rate limiting support for SB controller events
The copy of the patch that failed is found in:
   /var/lib/jenkins/jobs/upstream_build_from_pw/workspace/.git/rebase-apply/patch
When you have resolved this problem, run "git am --resolved".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".


Please check this out.  If you feel there has been an error, please email aconole@bytheb.org

Thanks,
0-day Robot

Acked-by: Mark Michelson <mmichels@redhat.com>

On 8/1/19 5:56 AM, Lorenzo Bianconi wrote:
> Introduce the capability to associate a meter to each controller event
> type in order to not overload the pinctrl thread under heavy load.
> Each event type relies on a meter with a defined name:
> - empty_lb_backends: event-elb
> 
> Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
> ---
>   northd/ovn-northd.c | 44 +++++++++++++++++++++++++++++++++++---------
>   ovn-nb.xml          |  8 ++++++++
>   tests/ovn.at        |  1 +
>   3 files changed, 44 insertions(+), 9 deletions(-)
> 
> diff --git a/northd/ovn-northd.c b/northd/ovn-northd.c
> index dabd422b5..e9c561265 100644
> --- a/northd/ovn-northd.c
> +++ b/northd/ovn-northd.c
> @@ -3879,7 +3879,8 @@ ls_has_dns_records(const struct nbrec_logical_switch *nbs)
>   }
>   
>   static void
> -build_pre_lb(struct ovn_datapath *od, struct hmap *lflows)
> +build_pre_lb(struct ovn_datapath *od, struct hmap *lflows,
> +             struct shash *meter_groups)
>   {
>       /* Do not send ND packets to conntrack */
>       ovn_lflow_add(lflows, od, S_SWITCH_IN_PRE_LB, 110,
> @@ -3917,7 +3918,11 @@ build_pre_lb(struct ovn_datapath *od, struct hmap *lflows)
>   
>               if (controller_event_en && !node->value[0]) {
>                   struct ds match = DS_EMPTY_INITIALIZER;
> -                char *action;
> +                char *meter = "", *action;
> +
> +                if (shash_find(meter_groups, "event-elb")) {
> +                    meter = "event-elb";
> +                }
>   
>                   if (addr_family == AF_INET) {
>                       ds_put_format(&match, "ip4.dst == %s && %s",
> @@ -3931,10 +3936,11 @@ build_pre_lb(struct ovn_datapath *od, struct hmap *lflows)
>                                     port);
>                   }
>                   action = xasprintf("trigger_event(event = \"%s\", "
> -                               "vip = \"%s\", protocol = \"%s\", "
> +                               "meter = \"%s\", vip = \"%s\", "
> +                               "protocol = \"%s\", "
>                                  "load_balancer = \"" UUID_FMT "\");",
>                                  event_to_string(OVN_EVENT_EMPTY_LB_BACKENDS),
> -                               node->key, lb->protocol,
> +                               meter, node->key, lb->protocol,
>                                  UUID_ARGS(&lb->header_.uuid));
>                   ovn_lflow_add(lflows, od, S_SWITCH_IN_PRE_LB, 120,
>                                 ds_cstr(&match), action);
> @@ -4761,7 +4767,8 @@ build_lrouter_groups(struct hmap *ports, struct ovs_list *lr_list)
>   static void
>   build_lswitch_flows(struct hmap *datapaths, struct hmap *ports,
>                       struct hmap *port_groups, struct hmap *lflows,
> -                    struct hmap *mcgroups, struct hmap *igmp_groups)
> +                    struct hmap *mcgroups, struct hmap *igmp_groups,
> +                    struct shash *meter_groups)
>   {
>       /* This flow table structure is documented in ovn-northd(8), so please
>        * update ovn-northd.8.xml if you change anything. */
> @@ -4778,7 +4785,7 @@ build_lswitch_flows(struct hmap *datapaths, struct hmap *ports,
>           }
>   
>           build_pre_acls(od, lflows);
> -        build_pre_lb(od, lflows);
> +        build_pre_lb(od, lflows, meter_groups);
>           build_pre_stateful(od, lflows);
>           build_acls(od, lflows, port_groups);
>           build_qos(od, lflows);
> @@ -7886,12 +7893,13 @@ build_lrouter_flows(struct hmap *datapaths, struct hmap *ports,
>   static void
>   build_lflows(struct northd_context *ctx, struct hmap *datapaths,
>                struct hmap *ports, struct hmap *port_groups,
> -             struct hmap *mcgroups, struct hmap *igmp_groups)
> +             struct hmap *mcgroups, struct hmap *igmp_groups,
> +             struct shash *meter_groups)
>   {
>       struct hmap lflows = HMAP_INITIALIZER(&lflows);
>   
>       build_lswitch_flows(datapaths, ports, port_groups, &lflows, mcgroups,
> -                        igmp_groups);
> +                        igmp_groups, meter_groups);
>       build_lrouter_flows(datapaths, ports, &lflows);
>   
>       /* Push changes to the Logical_Flow table to database. */
> @@ -8504,6 +8512,16 @@ build_mcast_groups(struct northd_context *ctx,
>       }
>   }
>   
> +static void
> +build_meter_groups(struct northd_context *ctx,
> +                   struct shash *meter_groups)
> +{
> +    const struct nbrec_meter *nb_meter;
> +    NBREC_METER_FOR_EACH (nb_meter, ctx->ovnnb_idl) {
> +        shash_add(meter_groups, nb_meter->name, nb_meter);
> +    }
> +}
> +
>   static void
>   ovnnb_db_run(struct northd_context *ctx,
>                struct ovsdb_idl_index *sbrec_chassis_by_name,
> @@ -8517,6 +8535,7 @@ ovnnb_db_run(struct northd_context *ctx,
>       struct hmap port_groups;
>       struct hmap mcast_groups;
>       struct hmap igmp_groups;
> +    struct shash meter_groups = SHASH_INITIALIZER(&meter_groups);
>   
>       build_datapaths(ctx, datapaths, lr_list);
>       build_ports(ctx, sbrec_chassis_by_name, datapaths, ports);
> @@ -8525,8 +8544,9 @@ ovnnb_db_run(struct northd_context *ctx,
>       build_lrouter_groups(ports, lr_list);
>       build_ip_mcast(ctx, datapaths);
>       build_mcast_groups(ctx, datapaths, ports, &mcast_groups, &igmp_groups);
> +    build_meter_groups(ctx, &meter_groups);
>       build_lflows(ctx, datapaths, ports, &port_groups, &mcast_groups,
> -                 &igmp_groups);
> +                 &igmp_groups, &meter_groups);
>   
>       sync_address_sets(ctx);
>       sync_port_groups(ctx);
> @@ -8547,6 +8567,12 @@ ovnnb_db_run(struct northd_context *ctx,
>       hmap_destroy(&mcast_groups);
>       hmap_destroy(&port_groups);
>   
> +    struct shash_node *node, *next;
> +    SHASH_FOR_EACH_SAFE (node, next, &meter_groups) {
> +        shash_delete(&meter_groups, node);
> +    }
> +    shash_destroy(&meter_groups);
> +
>       /* Sync ipsec configuration.
>        * Copy nb_cfg from northbound to southbound database.
>        * Also set up to update sb_cfg once our southbound transaction commits. */
> diff --git a/ovn-nb.xml b/ovn-nb.xml
> index 57b6edbf8..53f267ab6 100644
> --- a/ovn-nb.xml
> +++ b/ovn-nb.xml
> @@ -117,6 +117,14 @@
>           <ref table="Controller_Event"/> table.
>           The intention is for a CMS to see the events and take some sort of
>           action. Please see the <ref table="Controller_Event"/> table in SBDB.
> +        It is possible to associate a meter to each controller event type
> +        in order to not overload the pinctrl thread under heavy load.
> +        Each event type relies on a meter with a defined name:
> +
> +        <ul>
> +          <li>empty_lb_backends: event-elb</li>
> +        </ul>
> +
>         </column>
>       </group>
>   
> diff --git a/tests/ovn.at b/tests/ovn.at
> index 23159c876..8ff8cff0d 100644
> --- a/tests/ovn.at
> +++ b/tests/ovn.at
> @@ -14399,6 +14399,7 @@ ovn-nbctl --wait=hv set NB_Global . options:controller_event=true
>   ovn-nbctl lb-add lb0 192.168.1.100:80 ""
>   ovn-nbctl ls-lb-add sw0 lb0
>   uuid_lb=$(ovn-nbctl --bare --columns=_uuid find load_balancer name=lb0)
> +ovn-nbctl --wait=hv meter-add event-elb drop 100 pktps 10
>   
>   OVN_POPULATE_ARP
>   ovn-nbctl --timeout=3 --wait=hv sync
>