diff --git a/controller/modules/OverlayVisualizer.py b/controller/modules/OverlayVisualizer.py
index 4fe2fd7..7a7883c 100644
--- a/controller/modules/OverlayVisualizer.py
+++ b/controller/modules/OverlayVisualizer.py
@@ -38,7 +38,7 @@ class OverlayVisualizer(ControllerModule):
         # Visualizer webservice URL
         self._vis_address = "http://" + self._cm_config["WebServiceAddress"]
         self._req_url = "{}/EVIO/nodes/{}".format(self._vis_address, self.node_id)
-        self._vis_ds = None
+        self._vis_ds:dict
 
     def initialize(self):
         # We're using the pub-sub model here to gather data for the visualizer
@@ -109,21 +109,17 @@ class OverlayVisualizer(ControllerModule):
 
     def build_tunnel_data(self, ds):
         for olid in ds["VizData"]:
-            if (
-                "LinkManager" not in ds["VizData"][olid]
-                or "Topology" not in ds["VizData"][olid]
-            ):
-                continue
-
-            for tnlid in ds["VizData"][olid]["LinkManager"]:
-                ds["VizData"][olid]["Tunnels"][tnlid] = ds["VizData"][olid]["Topology"][
-                    tnlid
-                ]
-                ds["VizData"][olid]["Tunnels"][tnlid].update(
-                    ds["VizData"][olid]["LinkManager"][tnlid]
-                )
-            ds["VizData"][olid].pop("LinkManager")
-            ds["VizData"][olid].pop("Topology")
+            if ("Topology" in ds["VizData"][olid]):
+                for tnlid in ds["VizData"][olid]["Topology"]:
+                    ds["VizData"][olid]["Tunnels"][tnlid] = \
+                        ds["VizData"][olid]["Topology"][tnlid]
+            if ("LinkManager" in ds["VizData"][olid]):
+                for tnlid in ds["VizData"][olid]["LinkManager"]:
+                    ds["VizData"][olid]["Tunnels"][tnlid].update(
+                        ds["VizData"][olid]["LinkManager"][tnlid]
+                    )
+            ds["VizData"][olid].pop("LinkManager", None)
+            ds["VizData"][olid].pop("Topology", None)
         return ds
 
     def timer_method(self):
diff --git a/controller/modules/Topology.py b/controller/modules/Topology.py
index 7b18908..5a8e6b3 100644
--- a/controller/modules/Topology.py
+++ b/controller/modules/Topology.py
@@ -154,20 +154,22 @@ class Topology(ControllerModule, CFX):
             disc.presence()
             self._net_ovls[olid]["NewPeerCount"] += 1
             if self._net_ovls[olid]["NewPeerCount"] >= self.config["PeerDiscoveryCoalesce"]:
-                self.register_cbt("Logger", "LOG_DEBUG", "Coalesced {0} new peer discovery, "
-                                  "initiating network refresh"
-                                  .format(self._net_ovls[olid]["NewPeerCount"]))
+                self.log("LOG_DEBUG",
+                         "Overlay %s - Coalesced %s new peer discovery, "
+                         "initiating network refresh",
+                         olid, self._net_ovls[olid]["NewPeerCount"])
                 self._update_overlay(olid)
             else:
-                self.register_cbt("Logger", "LOG_DEBUG", "{0} new peers discovered, delaying "
-                                  "refresh".format(self._net_ovls[olid]["NewPeerCount"]))
+                self.log("LOG_DEBUG",
+                         "Overlay %s, %s new peers discovered, "
+                         "delaying refresh",
+                         olid, self._net_ovls[olid]["NewPeerCount"])
         cbt.set_response(None, True)
         self.complete_cbt(cbt)
 
     def req_handler_vis_data(self, cbt):
         topo_data = {}
         try:
-            edges = {}
             for olid in self._net_ovls:
                 topo_data[olid] = {}
                 nb = self._net_ovls[olid]["NetBuilder"]
@@ -179,9 +181,7 @@ class Topology(ControllerModule, CFX):
                                "CreatedTime": ce.created_time,
                                "ConnectedTime": ce.connected_time,
                                "State": ce.edge_state, "Type": ce.edge_type}
-                        edges[ce.edge_id] = ced
-                    if edges:
-                        topo_data[olid] = edges
+                        topo_data[olid][ce.edge_id] = ced
             cbt.set_response({"Topology": topo_data}, bool(topo_data))
             self.complete_cbt(cbt)
         except KeyError: