ovn-controller: Provide the option to configure inactivity probe interval for OpenFlow conn

If the ovn-controller main loop takes more than 5 seconds (if there are lots of logical
flows) before it calls poll_block(), it causes the poll_block to wake up immediately,
since rconn module has to send echo request. With the incremental processing, this is
not an issue as ovn-controller will not recompute again. But for older versions, this
is an issue as it causes flow recomputations and this would result in 100% cpu all the
time.

With this patch, CMS can configure a higher value depending the workload.

The main intention of this patch is to fix this recompuation issue for older versions
(there by requesting backport), it still would be beneficial with the
incremental processing engine.

Signed-off-by: Numan Siddique <nusiddiq@redhat.com>
Tested-by: Dumitru Ceara <dceara@redhat.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>

4 files changed, 42 insertions, 4 deletions

diff --git a/ovn/controller/ofctrl.c b/ovn/controller/ofctrl.c
index 47a915aea..043abd69d 100644
--- a/ovn/controller/ofctrl.c
+++ b/ovn/controller/ofctrl.c
@@ -169,9 +169,11 @@ static void ofctrl_recv(const struct ofp_header *, enum ofptype);
 
 void
 ofctrl_init(struct ovn_extend_table *group_table,
-            struct ovn_extend_table *meter_table)
+            struct ovn_extend_table *meter_table,
+            int inactivity_probe_interval)
 {
-    swconn = rconn_create(5, 0, DSCP_DEFAULT, 1 << OFP13_VERSION);
+    swconn = rconn_create(inactivity_probe_interval, 0,
+                          DSCP_DEFAULT, 1 << OFP13_VERSION);
     tx_counter = rconn_packet_counter_create();
     hmap_init(&installed_flows);
     ovs_list_init(&flow_updates);
@@ -1381,3 +1383,11 @@ ofctrl_is_connected(void)
 {
     return rconn_is_connected(swconn);
 }
+
+void
+ofctrl_set_probe_interval(int probe_interval)
+{
+    if (swconn) {
+        rconn_set_probe_interval(swconn, probe_interval);
+    }
+}
diff --git a/ovn/controller/ofctrl.h b/ovn/controller/ofctrl.h
index b39cdf88b..ed8918aae 100644
--- a/ovn/controller/ofctrl.h
+++ b/ovn/controller/ofctrl.h
@@ -41,7 +41,8 @@ struct ovn_desired_flow_table {
 
 /* Interface for OVN main loop. */
 void ofctrl_init(struct ovn_extend_table *group_table,
-                 struct ovn_extend_table *meter_table);
+                 struct ovn_extend_table *meter_table,
+                 int inactivity_probe_interval);
 void ofctrl_run(const struct ovsrec_bridge *br_int,
                 struct shash *pending_ct_zones);
 enum mf_field_id ofctrl_get_mf_field_id(void);
@@ -81,5 +82,6 @@ void ofctrl_check_and_add_flow(struct ovn_desired_flow_table *,
                                const struct uuid *, bool log_duplicate_flow);
 
 bool ofctrl_is_connected(void);
+void ofctrl_set_probe_interval(int probe_interval);
 
 #endif /* ovn/ofctrl.h */
diff --git a/ovn/controller/ovn-controller.8.xml b/ovn/controller/ovn-controller.8.xml
index 9721d9a5b..8f9c64838 100644
--- a/ovn/controller/ovn-controller.8.xml
+++ b/ovn/controller/ovn-controller.8.xml
@@ -112,6 +112,20 @@
         </p>
       </dd>
 
+      <dt><code>external_ids:ovn-openflow-probe-interval</code></dt>
+      <dd>
+        <p>
+          The inactivity probe interval of the OpenFlow connection to the
+          OpenvSwitch integration bridge, in seconds.
+          If the value is zero, it disables the connection keepalive feature.
+        </p>
+
+        <p>
+          If the value is nonzero, then it will be forced to a value of
+          at least 5s.
+        </p>
+      </dd>
+
       <dt><code>external_ids:ovn-encap-type</code></dt>
       <dd>
         <p>
diff --git a/ovn/controller/ovn-controller.c b/ovn/controller/ovn-controller.c
index 60190161f..c2c68e467 100644
--- a/ovn/controller/ovn-controller.c
+++ b/ovn/controller/ovn-controller.c
@@ -73,6 +73,7 @@ static unixctl_cb_func ovn_controller_conn_show;
 
 #define DEFAULT_BRIDGE_NAME "br-int"
 #define DEFAULT_PROBE_INTERVAL_MSEC 5000
+#define OFCTRL_DEFAULT_PROBE_INTERVAL_SEC 5
 
 #define CONTROLLER_LOOP_STOPWATCH_NAME "ovn-controller-flow-generation"
 
@@ -390,6 +391,15 @@ update_ssl_config(const struct ovsrec_ssl_table *ssl_table)
     }
 }
 
+static int
+get_ofctrl_probe_interval(struct ovsdb_idl *ovs_idl)
+{
+    const struct ovsrec_open_vswitch *cfg = ovsrec_open_vswitch_first(ovs_idl);
+    return smap_get_int(&cfg->external_ids,
+                        "ovn-openflow-probe-interval",
+                        OFCTRL_DEFAULT_PROBE_INTERVAL_SEC);
+}
+
 /* Retrieves the pointer to the OVN Southbound database from 'ovs_idl' and
  * updates 'sbdb_idl' with that pointer. */
 static void
@@ -1817,7 +1827,8 @@ main(int argc, char *argv[])
     engine_init(&en_flow_output);
 
     ofctrl_init(&ed_flow_output.group_table,
-                &ed_flow_output.meter_table);
+                &ed_flow_output.meter_table,
+                get_ofctrl_probe_interval(ovs_idl_loop.idl));
 
     unixctl_command_register("group-table-list", "", 0, 0,
                              group_table_list, &ed_flow_output.group_table);
@@ -1844,6 +1855,7 @@ main(int argc, char *argv[])
     while (!exiting) {
         update_sb_db(ovs_idl_loop.idl, ovnsb_idl_loop.idl);
         update_ssl_config(ovsrec_ssl_table_get(ovs_idl_loop.idl));
+        ofctrl_set_probe_interval(get_ofctrl_probe_interval(ovs_idl_loop.idl));
         old_engine_run_id = engine_run_id;
 
         struct ovsdb_idl_txn *ovs_idl_txn = ovsdb_idl_loop_run(&ovs_idl_loop);