diff --git a/osm_ro/vim_thread.py b/osm_ro/vim_thread.py
index d5301f1..8002436 100644
--- a/osm_ro/vim_thread.py
+++ b/osm_ro/vim_thread.py
@@ -149,8 +149,7 @@
                        'dt.vim_tenant_name as vim_tenant_name', 'dt.vim_tenant_id as vim_tenant_id',
                        'user', 'passwd', 'dt.config as dt_config')
             where_ = {"dt.uuid": self.datacenter_tenant_id}
-            with self.db_lock:
-                vims = self.db.get_rows(FROM=from_, SELECT=select_, WHERE=where_)
+            vims = self.db.get_rows(FROM=from_, SELECT=select_, WHERE=where_)
             vim = vims[0]
             vim_config = {}
             if vim["config"]:
@@ -161,8 +160,9 @@
             vim_config['datacenter_id'] = vim.get('datacenter_id')
 
             # get port_mapping
-            vim_config["wim_external_ports"] = self.ovim.get_of_port_mappings(
-                db_filter={"region": vim_config['datacenter_id'], "pci": None})
+            with self.db_lock:
+                vim_config["wim_external_ports"] = self.ovim.get_of_port_mappings(
+                    db_filter={"region": vim_config['datacenter_id'], "pci": None})
 
             self.vim = vim_module[vim["type"]].vimconnector(
                 uuid=vim['datacenter_id'], name=vim['datacenter_name'],
@@ -193,12 +193,11 @@
             database_limit = 200
             while True:
                 # get 200 (database_limit) entries each time
-                with self.db_lock:
-                    vim_actions = self.db.get_rows(FROM="vim_wim_actions",
-                                                   WHERE={"datacenter_vim_id": self.datacenter_tenant_id,
-                                                          "item_id>=": old_item_id},
-                                                   ORDER_BY=("item_id", "item", "created_at",),
-                                                   LIMIT=database_limit)
+                vim_actions = self.db.get_rows(FROM="vim_wim_actions",
+                                                WHERE={"datacenter_vim_id": self.datacenter_tenant_id,
+                                                        "item_id>=": old_item_id},
+                                                ORDER_BY=("item_id", "item", "created_at",),
+                                                LIMIT=database_limit)
                 for task in vim_actions:
                     item = task["item"]
                     item_id = task["item_id"]
@@ -342,12 +341,12 @@
                                     with self.db_lock:
                                         sdn_port_id = self.ovim.new_external_port(
                                             {"compute_node": interface["compute_node"],
-                                             "pci": interface["pci"],
-                                             "vlan": interface.get("vlan"),
-                                             "net_id": sdn_net_id,
-                                             "region": self.vim["config"]["datacenter_id"],
-                                             "name": sdn_port_name,
-                                             "mac": interface.get("mac_address")})
+                                                "pci": interface["pci"],
+                                                "vlan": interface.get("vlan"),
+                                                "net_id": sdn_net_id,
+                                                "region": self.vim["config"]["datacenter_id"],
+                                                "name": sdn_port_name,
+                                                "mac": interface.get("mac_address")})
                                         task_interface["sdn_port_id"] = sdn_port_id
                                         task_need_update = True
                                 except (ovimException, Exception) as e:
@@ -360,18 +359,17 @@
                                     task_warning_msg += error_text
                                     # TODO Set error_msg at instance_nets instead of instance VMs
 
-                            with self.db_lock:
-                                self.db.update_rows(
-                                    'instance_interfaces',
-                                    UPDATE={"mac_address": interface.get("mac_address"),
-                                            "ip_address": interface.get("ip_address"),
-                                            "vim_interface_id": interface.get("vim_interface_id"),
-                                            "vim_info": interface.get("vim_info"),
-                                            "sdn_port_id": task_interface.get("sdn_port_id"),
-                                            "compute_node": interface.get("compute_node"),
-                                            "pci": interface.get("pci"),
-                                            "vlan": interface.get("vlan")},
-                                    WHERE={'uuid': task_interface["iface_id"]})
+                            self.db.update_rows(
+                                'instance_interfaces',
+                                UPDATE={"mac_address": interface.get("mac_address"),
+                                        "ip_address": interface.get("ip_address"),
+                                        "vim_interface_id": interface.get("vim_interface_id"),
+                                        "vim_info": interface.get("vim_info"),
+                                        "sdn_port_id": task_interface.get("sdn_port_id"),
+                                        "compute_node": interface.get("compute_node"),
+                                        "pci": interface.get("pci"),
+                                        "vlan": interface.get("vlan")},
+                                WHERE={'uuid': task_interface["iface_id"]})
                             task["vim_interfaces"][vim_interface_id] = interface
 
                     # check and update task and instance_vms database
@@ -388,8 +386,7 @@
                         temp_dict = {"status": vim_info["status"], "error_msg": vim_info_error_msg}
                         if vim_info.get("vim_info"):
                             temp_dict["vim_info"] = vim_info["vim_info"]
-                        with self.db_lock:
-                            self.db.update_rows('instance_vms', UPDATE=temp_dict, WHERE={"uuid": task["item_id"]})
+                        self.db.update_rows('instance_vms', UPDATE=temp_dict, WHERE={"uuid": task["item_id"]})
                         task["extra"]["vim_status"] = vim_info["status"]
                         task["error_msg"] = vim_info_error_msg
                         if vim_info.get("vim_info"):
@@ -397,13 +394,12 @@
                         task_need_update = True
 
                     if task_need_update:
-                        with self.db_lock:
-                            self.db.update_rows(
-                                'vim_wim_actions',
-                                UPDATE={"extra": yaml.safe_dump(task["extra"], default_flow_style=True, width=256),
-                                        "error_msg": task.get("error_msg"), "modified_at": now},
-                                WHERE={'instance_action_id': task['instance_action_id'],
-                                       'task_index': task['task_index']})
+                        self.db.update_rows(
+                            'vim_wim_actions',
+                            UPDATE={"extra": yaml.safe_dump(task["extra"], default_flow_style=True, width=256),
+                                    "error_msg": task.get("error_msg"), "modified_at": now},
+                            WHERE={'instance_action_id': task['instance_action_id'],
+                                    'task_index': task['task_index']})
                     if task["extra"].get("vim_status") == "BUILD":
                         self._insert_refresh(task, now + self.REFRESH_BUILD)
                     else:
@@ -466,14 +462,13 @@
                         temp_dict = {"status": vim_info_status, "error_msg": vim_info_error_msg}
                         if vim_info.get("vim_info"):
                             temp_dict["vim_info"] = vim_info["vim_info"]
-                        with self.db_lock:
-                            self.db.update_rows('instance_nets', UPDATE=temp_dict, WHERE={"uuid": task["item_id"]})
-                            self.db.update_rows(
-                                'vim_wim_actions',
-                                UPDATE={"extra": yaml.safe_dump(task["extra"], default_flow_style=True, width=256),
-                                        "error_msg": task.get("error_msg"), "modified_at": now},
-                                WHERE={'instance_action_id': task['instance_action_id'],
-                                       'task_index': task['task_index']})
+                        self.db.update_rows('instance_nets', UPDATE=temp_dict, WHERE={"uuid": task["item_id"]})
+                        self.db.update_rows(
+                            'vim_wim_actions',
+                            UPDATE={"extra": yaml.safe_dump(task["extra"], default_flow_style=True, width=256),
+                                    "error_msg": task.get("error_msg"), "modified_at": now},
+                            WHERE={'instance_action_id': task['instance_action_id'],
+                                    'task_index': task['task_index']})
                     if task["extra"].get("vim_status") == "BUILD":
                         self._insert_refresh(task, now + self.REFRESH_BUILD)
                     else:
@@ -648,23 +643,22 @@
                 task["vim_id"] if task["status"] == "DONE" else task.get("error_msg"), task["params"]))
             try:
                 now = time.time()
-                with self.db_lock:
+                self.db.update_rows(
+                    table="vim_wim_actions",
+                    UPDATE={"status": task["status"], "vim_id": task.get("vim_id"), "modified_at": now,
+                            "error_msg": task["error_msg"],
+                            "extra": yaml.safe_dump(task["extra"], default_flow_style=True, width=256)},
+                    WHERE={"instance_action_id": task["instance_action_id"], "task_index": task["task_index"]})
+                if result is not None:
                     self.db.update_rows(
-                        table="vim_wim_actions",
-                        UPDATE={"status": task["status"], "vim_id": task.get("vim_id"), "modified_at": now,
-                                "error_msg": task["error_msg"],
-                                "extra": yaml.safe_dump(task["extra"], default_flow_style=True, width=256)},
-                        WHERE={"instance_action_id": task["instance_action_id"], "task_index": task["task_index"]})
-                    if result is not None:
-                        self.db.update_rows(
-                            table="instance_actions",
-                            UPDATE={("number_done" if result else "number_failed"): {"INCREMENT": 1},
-                                    "modified_at": now},
-                            WHERE={"uuid": task["instance_action_id"]})
-                    if database_update:
-                        self.db.update_rows(table=task["item"],
-                                            UPDATE=database_update,
-                                            WHERE={"uuid": task["item_id"]})
+                        table="instance_actions",
+                        UPDATE={("number_done" if result else "number_failed"): {"INCREMENT": 1},
+                                "modified_at": now},
+                        WHERE={"uuid": task["instance_action_id"]})
+                if database_update:
+                    self.db.update_rows(table=task["item"],
+                                        UPDATE=database_update,
+                                        WHERE={"uuid": task["item_id"]})
             except db_base_Exception as e:
                 self.logger.error("task={} Error updating database {}".format(task_id, e), exc_info=True)
 
@@ -816,9 +810,8 @@
             if ins_action_id:
                 instance_action_id = ins_action_id
 
-        with self.db_lock:
-            tasks = self.db.get_rows(FROM="vim_wim_actions", WHERE={"instance_action_id": instance_action_id,
-                                                                "task_index": task_index})
+        tasks = self.db.get_rows(FROM="vim_wim_actions", WHERE={"instance_action_id": instance_action_id,
+                                                            "task_index": task_index})
         if not tasks:
             return None
         task = tasks[0]
@@ -868,11 +861,10 @@
             task_interfaces = {}
             for iface in params_copy[5]:
                 task_interfaces[iface["vim_id"]] = {"iface_id": iface["uuid"]}
-                with self.db_lock:
-                    result = self.db.get_rows(
-                        SELECT=('sdn_net_id', 'interface_id'),
-                        FROM='instance_nets as ine join instance_interfaces as ii on ii.instance_net_id=ine.uuid',
-                        WHERE={'ii.uuid': iface["uuid"]})
+                result = self.db.get_rows(
+                    SELECT=('sdn_net_id', 'interface_id'),
+                    FROM='instance_nets as ine join instance_interfaces as ii on ii.instance_net_id=ine.uuid',
+                    WHERE={'ii.uuid': iface["uuid"]})
                 if result:
                     task_interfaces[iface["vim_id"]]["sdn_net_id"] = result[0]['sdn_net_id']
                     task_interfaces[iface["vim_id"]]["interface_id"] = result[0]['interface_id']
@@ -946,11 +938,10 @@
 
         # Discover if this network is managed by a sdn controller
         sdn_net_id = None
-        with self.db_lock:
-            result = self.db.get_rows(SELECT=('sdn_net_id',), FROM='instance_nets',
-                                      WHERE={'vim_net_id': vim_net_id,
-                                             'datacenter_tenant_id': self.datacenter_tenant_id},
-                                      ORDER="instance_scenario_id")
+        result = self.db.get_rows(SELECT=('sdn_net_id',), FROM='instance_nets',
+                                    WHERE={'vim_net_id': vim_net_id,
+                                            'datacenter_tenant_id': self.datacenter_tenant_id},
+                                    ORDER="instance_scenario_id")
         if result:
             sdn_net_id = result[0]['sdn_net_id']
 
@@ -1035,10 +1026,12 @@
                         "name": sdn_port_name,
                     }
                     try:
-                        sdn_external_port_id = self.ovim.new_external_port(sdn_port_data)
+                        with self.db_lock:
+                            sdn_external_port_id = self.ovim.new_external_port(sdn_port_data)
                     except ovimException:
                         sdn_port_data["compute_node"] = "__WIM"
-                        sdn_external_port_id = self.ovim.new_external_port(sdn_port_data)
+                        with self.db_lock:
+                            sdn_external_port_id = self.ovim.new_external_port(sdn_port_data)
                     self.logger.debug("Added sdn_external_port {} to sdn_network {}".format(sdn_external_port_id,
                                                                                             sdn_net_id))