diff --git a/ovsdb/ovsdb-server.c b/ovsdb/ovsdb-server.c
index 65a47a4..4e97de8 100644
--- a/ovsdb/ovsdb-server.c
+++ b/ovsdb/ovsdb-server.c
@@ -219,6 +219,7 @@ main_loop(struct server_config *config,
         struct shash_node *next;
         SHASH_FOR_EACH_SAFE (node, next, all_dbs) {
             struct db *db = node->data;
+            ovsdb_txn_history_run(db->db);
             if (ovsdb_trigger_run(db->db, time_msec())) {
                 /* The message below is currently the only reason to disconnect
                  * all clients. */
@@ -568,6 +569,7 @@ parse_txn(struct server_config *config, struct db *db,
 
         error = ovsdb_file_txn_from_json(db->db, txn_json, false, &txn);
         if (!error) {
+            ovsdb_txn_set_txnid(txnid, txn);
             log_and_free_error(ovsdb_txn_replay_commit(txn));
         }
         if (!error && !uuid_is_zero(txnid)) {
@@ -658,6 +660,11 @@ open_db(struct server_config *config, const char *filename)
     db->db = ovsdb_create(schema, storage);
     ovsdb_jsonrpc_server_add_db(config->jsonrpc, db->db);
 
+    /* Enable txn history for clustered mode. It is not enabled for other mode
+     * for now, since txn id is available for clustered mode only. */
+    if (ovsdb_storage_is_clustered(storage)) {
+        ovsdb_txn_history_init(db->db);
+    }
     read_db(config, db);
 
     error = (db->db->name[0] == '_'
@@ -695,6 +702,8 @@ add_server_db(struct server_config *config)
     json_destroy(schema_json);
 
     struct db *db = xzalloc(sizeof *db);
+    /* We don't need txn_history for server_db. */
+
     db->filename = xstrdup("<internal>");
     db->db = ovsdb_create(schema, ovsdb_storage_create_unbacked());
     bool ok OVS_UNUSED = ovsdb_jsonrpc_server_add_db(config->jsonrpc, db->db);
diff --git a/ovsdb/ovsdb.c b/ovsdb/ovsdb.c
index da8db82..cfc96b3 100644
--- a/ovsdb/ovsdb.c
+++ b/ovsdb/ovsdb.c
@@ -455,6 +455,9 @@ ovsdb_destroy(struct ovsdb *db)
         /* Remove all the monitors. */
         ovsdb_monitors_remove(db);
 
+        /* Destroy txn history. */
+        ovsdb_txn_history_destroy(db);
+
         /* The caller must ensure that no triggers remain. */
         ovs_assert(ovs_list_is_empty(&db->triggers));
 
@@ -535,6 +538,9 @@ ovsdb_replace(struct ovsdb *dst, struct ovsdb *src)
         ovsdb_trigger_prereplace_db(trigger);
     }
 
+    /* Destroy txn history. */
+    ovsdb_txn_history_destroy(dst);
+
     struct ovsdb_schema *tmp_schema = dst->schema;
     dst->schema = src->schema;
     src->schema = tmp_schema;
diff --git a/ovsdb/ovsdb.h b/ovsdb/ovsdb.h
index d96b1c2..32e5333 100644
--- a/ovsdb/ovsdb.h
+++ b/ovsdb/ovsdb.h
@@ -67,6 +67,11 @@ bool ovsdb_parse_version(const char *, struct ovsdb_version *);
 bool ovsdb_is_valid_version(const char *);
 
 /* Database. */
+struct ovsdb_txn_history_node {
+    struct ovs_list node; /* Element in struct ovsdb's txn_history list */
+    struct ovsdb_txn *txn;
+};
+
 struct ovsdb {
     char *name;
     struct ovsdb_schema *schema;
@@ -80,6 +85,11 @@ struct ovsdb {
     bool run_triggers;
 
     struct ovsdb_table *rbac_role;
+
+    /* History trasanctions for incremental monitor transfer. */
+    bool need_txn_history;     /* Need to maintain history of transactions. */
+    unsigned int n_txn_history; /* Current number of history transactions. */
+    struct ovs_list txn_history; /* Contains "struct ovsdb_txn_history_node. */
 };
 
 struct ovsdb *ovsdb_create(struct ovsdb_schema *, struct ovsdb_storage *);
diff --git a/ovsdb/transaction.c b/ovsdb/transaction.c
index 5a43132..148d108 100644
--- a/ovsdb/transaction.c
+++ b/ovsdb/transaction.c
@@ -40,6 +40,7 @@ struct ovsdb_txn {
     struct ovsdb *db;
     struct ovs_list txn_tables; /* Contains "struct ovsdb_txn_table"s. */
     struct ds comment;
+    struct uuid txnid; /* For clustered mode only. It is the eid. */
 };
 
 /* A table modified by a transaction. */
@@ -106,13 +107,19 @@ static unsigned int serial;
 struct ovsdb_txn *
 ovsdb_txn_create(struct ovsdb *db)
 {
-    struct ovsdb_txn *txn = xmalloc(sizeof *txn);
+    struct ovsdb_txn *txn = xzalloc(sizeof *txn);
     txn->db = db;
     ovs_list_init(&txn->txn_tables);
     ds_init(&txn->comment);
     return txn;
 }
 
+void
+ovsdb_txn_set_txnid(const struct uuid *txnid, struct ovsdb_txn *txn)
+{
+    txn->txnid = *txnid;
+}
+
 static void
 ovsdb_txn_free(struct ovsdb_txn *txn)
 {
@@ -881,11 +888,79 @@ ovsdb_txn_precommit(struct ovsdb_txn *txn)
     return error;
 }
 
+static struct ovsdb_txn*
+ovsdb_txn_clone(const struct ovsdb_txn *txn)
+{
+    struct ovsdb_txn *txn_cloned = xzalloc(sizeof *txn_cloned);
+    ovs_list_init(&txn_cloned->txn_tables);
+    txn_cloned->txnid = txn->txnid;
+
+    struct ovsdb_txn_table *t;
+    LIST_FOR_EACH (t, node, &txn->txn_tables) {
+        struct ovsdb_txn_table *t_cloned = xmalloc(sizeof *t_cloned);
+        ovs_list_push_back(&txn_cloned->txn_tables, &t_cloned->node);
+        hmap_init(&t_cloned->txn_rows);
+
+        struct ovsdb_txn_row *r;
+        HMAP_FOR_EACH (r, hmap_node, &t->txn_rows) {
+            size_t n_columns = shash_count(&t->table->schema->columns);
+            struct ovsdb_txn_row *r_cloned =
+                xzalloc(offsetof(struct ovsdb_txn_row, changed)
+                        + bitmap_n_bytes(n_columns));
+
+            r_cloned->uuid = r->uuid;
+            r_cloned->table = r->table;
+            r_cloned->old = r->old ? ovsdb_row_clone(r->old) : NULL;
+            r_cloned->new = r->new ? ovsdb_row_clone(r->new) : NULL;
+            memcpy(&r_cloned->changed, &r->changed, bitmap_n_bytes(n_columns));
+            hmap_insert(&t_cloned->txn_rows, &r_cloned->hmap_node,
+                        uuid_hash(&r_cloned->uuid));
+        }
+    }
+    return txn_cloned;
+}
+
+static void
+ovsdb_txn_destroy_cloned(struct ovsdb_txn *txn)
+{
+    ovs_assert(!txn->db);
+    struct ovsdb_txn_table *t, *next_txn_table;
+    LIST_FOR_EACH_SAFE (t, next_txn_table, node, &txn->txn_tables) {
+        struct ovsdb_txn_row *r, *next_txn_row;
+        HMAP_FOR_EACH_SAFE (r, next_txn_row, hmap_node, &t->txn_rows) {
+            if (r->old) {
+                ovsdb_row_destroy(r->old);
+            }
+            if (r->new) {
+                ovsdb_row_destroy(r->new);
+            }
+            hmap_remove(&t->txn_rows, &r->hmap_node);
+            free(r);
+        }
+        hmap_destroy(&t->txn_rows);
+        ovs_list_remove(&t->node);
+        free(t);
+    }
+    free(txn);
+}
+
+static void
+ovsdb_txn_add_to_history(struct ovsdb_txn *txn)
+{
+    if (txn->db->need_txn_history) {
+        struct ovsdb_txn_history_node *node = xzalloc(sizeof *node);
+        node->txn = ovsdb_txn_clone(txn);
+        ovs_list_push_back(&txn->db->txn_history, &node->node);
+        txn->db->n_txn_history++;
+    }
+}
+
 /* Finalize commit. */
 void
 ovsdb_txn_complete(struct ovsdb_txn *txn)
 {
     if (!ovsdb_txn_is_empty(txn)) {
+
         txn->db->run_triggers = true;
         ovsdb_monitors_commit(txn->db, txn);
         ovsdb_error_assert(for_each_txn_row(txn, ovsdb_txn_update_weak_refs));
@@ -906,6 +981,7 @@ ovsdb_txn_replay_commit(struct ovsdb_txn *txn)
     if (error) {
         ovsdb_txn_abort(txn);
     } else {
+        ovsdb_txn_add_to_history(txn);
         ovsdb_txn_complete(txn);
     }
     return error;
@@ -1304,3 +1380,46 @@ for_each_txn_row(struct ovsdb_txn *txn,
 
     return NULL;
 }
+
+void
+ovsdb_txn_history_run(struct ovsdb *db)
+{
+    if (!db->need_txn_history) {
+        return;
+    }
+    /* Remove old histories to limit the size of the history */
+    while (db->n_txn_history > 100) {
+        struct ovsdb_txn_history_node *txn_h_node = CONTAINER_OF(
+                ovs_list_pop_front(&db->txn_history),
+                struct ovsdb_txn_history_node, node);
+
+        ovsdb_txn_destroy_cloned(txn_h_node->txn);
+        free(txn_h_node);
+        db->n_txn_history--;
+    }
+}
+
+void
+ovsdb_txn_history_init(struct ovsdb *db)
+{
+    db->need_txn_history = true;
+    db->n_txn_history = 0;
+    ovs_list_init(&db->txn_history);
+}
+
+void
+ovsdb_txn_history_destroy(struct ovsdb *db)
+{
+
+    if (!db->need_txn_history) {
+        return;
+    }
+
+    struct ovsdb_txn_history_node *txn_h_node, *next;
+    LIST_FOR_EACH_SAFE (txn_h_node, next, node, &db->txn_history) {
+        ovs_list_remove(&txn_h_node->node);
+        ovsdb_txn_destroy_cloned(txn_h_node->txn);
+        free(txn_h_node);
+    }
+    db->n_txn_history = 0;
+}
diff --git a/ovsdb/transaction.h b/ovsdb/transaction.h
index 32384fc..5e62ef0 100644
--- a/ovsdb/transaction.h
+++ b/ovsdb/transaction.h
@@ -25,6 +25,7 @@ struct ovsdb_table;
 struct uuid;
 
 struct ovsdb_txn *ovsdb_txn_create(struct ovsdb *);
+void ovsdb_txn_set_txnid(const struct uuid *, struct ovsdb_txn *);
 void ovsdb_txn_abort(struct ovsdb_txn *);
 
 struct ovsdb_error *ovsdb_txn_replay_commit(struct ovsdb_txn *)
@@ -59,5 +60,8 @@ void ovsdb_txn_for_each_change(const struct ovsdb_txn *,
 
 void ovsdb_txn_add_comment(struct ovsdb_txn *, const char *);
 const char *ovsdb_txn_get_comment(const struct ovsdb_txn *);
+void ovsdb_txn_history_run(struct ovsdb *);
+void ovsdb_txn_history_init(struct ovsdb *);
+void ovsdb_txn_history_destroy(struct ovsdb *);
 
 #endif /* ovsdb/transaction.h */
