[ovs-dev,v2,1/2] ovsdb-idl: Provide API to disable set_db_change_aware request.

diff --git a/lib/ovsdb-cs.c b/lib/ovsdb-cs.c
index 0fca03d7231e..e26403648920 100644
--- a/lib/ovsdb-cs.c
+++ b/lib/ovsdb-cs.c
@@ -219,6 +219,9 @@  struct ovsdb_cs {
     struct uuid cid;
     struct hmap server_rows;
 
+    /* Whether to send 'set_db_change_aware'. */
+    bool set_db_change_aware;
+
     /* Clustered servers. */
     uint64_t min_index;      /* Minimum allowed index, to avoid regression. */
     bool leader_only;        /* If true, do not connect to Raft followers. */
@@ -331,6 +334,7 @@  ovsdb_cs_create(const char *db_name, int max_version,
     cs->request_id = NULL;
     cs->leader_only = true;
     cs->shuffle_remotes = true;
+    cs->set_db_change_aware = true;
     hmap_init(&cs->server_rows);
 
     return cs;
@@ -461,7 +465,7 @@  ovsdb_cs_process_response(struct ovsdb_cs *cs, struct jsonrpc_msg *msg)
             cs->server.monitor_version = cs->server.max_version;
             ovsdb_cs_db_parse_monitor_reply(&cs->server, msg->result,
                                             cs->server.monitor_version);
-            if (ovsdb_cs_check_server_db(cs)) {
+            if (ovsdb_cs_check_server_db(cs) && cs->set_db_change_aware) {
                 ovsdb_cs_send_db_change_aware(cs);
             }
         } else {
@@ -1150,6 +1154,22 @@  ovsdb_cs_send_cond_change(struct ovsdb_cs *cs)
     }
 }
 
+/* Database change awareness. */
+
+/* By default, or if 'db_change_aware' is true, 'cs' will send
+ * 'set_db_change_aware' request to the server after receiving the _SERVER data
+ * (when the server supports it), which is useful for clients that intends to
+ * keep long connections to the server. Otherwise, 'cs' will not send the
+ * 'set_db_change_aware' request, which is more reasonable for short-lived
+ * connections to avoid unnecessary processing at the server side and possible
+ * error handling due to connections being closed by the clients before the
+ * responses are sent by the server. */
+void
+ovsdb_cs_set_db_change_aware(struct ovsdb_cs *cs, bool set_db_change_aware)
+{
+    cs->set_db_change_aware = set_db_change_aware;
+}
+
 /* Clustered servers. */
 
 /* By default, or if 'leader_only' is true, when 'cs' connects to a clustered
diff --git a/lib/ovsdb-cs.h b/lib/ovsdb-cs.h
index 5d5b58f0a0a6..4cf9ca2b99c1 100644
--- a/lib/ovsdb-cs.h
+++ b/lib/ovsdb-cs.h
@@ -142,6 +142,9 @@  unsigned int ovsdb_cs_set_condition(struct ovsdb_cs *, const char *table,
                                     const struct json *condition);
 unsigned int ovsdb_cs_get_condition_seqno(const struct ovsdb_cs *);
 
+/* Database change awareness. */
+void ovsdb_cs_set_db_change_aware(struct ovsdb_cs *, bool set_db_change_aware);
+
 /* Clustered servers. */
 void ovsdb_cs_set_leader_only(struct ovsdb_cs *, bool leader_only);
 void ovsdb_cs_set_shuffle_remotes(struct ovsdb_cs *, bool shuffle);
diff --git a/lib/ovsdb-idl.c b/lib/ovsdb-idl.c
index dbdfe45d87ea..634fbb56df24 100644
--- a/lib/ovsdb-idl.c
+++ b/lib/ovsdb-idl.c
@@ -321,6 +321,14 @@  ovsdb_idl_set_shuffle_remotes(struct ovsdb_idl *idl, bool shuffle)
     ovsdb_cs_set_shuffle_remotes(idl->cs, shuffle);
 }
 
+/* Passes 'set_db_change_aware' to ovsdb_cs_set_db_change_aware().  See that
+ * function for documentation. */
+void
+ovsdb_idl_set_db_change_aware(struct ovsdb_idl *idl, bool set_db_change_aware)
+{
+    ovsdb_cs_set_db_change_aware(idl->cs, set_db_change_aware);
+}
+
 /* Reset min_index to 0. This prevents a situation where the client
  * thinks all databases have stale data, when they actually have all
  * been destroyed and rebuilt from scratch.
diff --git a/lib/ovsdb-idl.h b/lib/ovsdb-idl.h
index 9a3e19f20553..86fd2bd36f27 100644
--- a/lib/ovsdb-idl.h
+++ b/lib/ovsdb-idl.h
@@ -66,6 +66,8 @@  struct ovsdb_idl *ovsdb_idl_create_unconnected(
     const struct ovsdb_idl_class *, bool monitor_everything_by_default);
 void ovsdb_idl_set_remote(struct ovsdb_idl *, const char *remote, bool retry);
 void ovsdb_idl_set_shuffle_remotes(struct ovsdb_idl *, bool shuffle);
+void ovsdb_idl_set_db_change_aware(struct ovsdb_idl *,
+                                   bool set_db_change_aware);
 void ovsdb_idl_reset_min_index(struct ovsdb_idl *);
 void ovsdb_idl_destroy(struct ovsdb_idl *);