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

Lorenzo Bianconi lorenzo.bianconi at redhat.com
Thu Aug 1 09:56:01 UTC 2019


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 at 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
-- 
2.21.0



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