Add the feature of viewing traffic inside every node in the cluster

apps/epl/src/epl_traffic.erl

@@ -26,7 +26,8 @@
 
 -record(state, {subscribers = [],
                 traffic = [],
-                msg_pass = #{}}).
+                msg_pass = #{},
+                viz_map = undefined}).
 
 %%%===================================================================
 %%% API functions
@@ -47,7 +48,8 @@ unsubscribe() ->
 
 init([]) ->
     %% Subscribe to all events from the observed node
-    ok = epl:subscribe(default_node),
+    Reply = epl:subscribe(),
+    true = verify_subscribe_reply(Reply),
 
     %% Initialise counters, so that later we can calculate deltas
     TrafficCounters = get_traffic_counters(),
@@ -66,25 +68,19 @@ handle_cast(Request, _State) ->
 handle_info({data, {Node, _Timestamp}, Proplist},
             State = #state{subscribers = Subs,
                            traffic = OldTraffic,
-                           msg_pass = OldMsgPass}) ->
-
-    {Viz1, NewTraffic} = update_traffic_graph(Node, OldTraffic,
-                                              epl_viz_map:new(Node)),
-
-
-    %% We're starting from observed node which is our graph entry point
-    Viz2 = get_message_passing_counters(Node, Proplist,
-                                        Viz1, OldMsgPass),
-
-    %% push an update to all subscribed WebSockets
-    JSON = epl_json:encode(Viz2, <<"traffic-info">>),
-
-    [Pid ! {data, JSON} || Pid <- Subs],
-    {noreply, State#state{traffic = NewTraffic}};
+                           msg_pass = OldMsgPass,
+                           viz_map = OldViz}) ->
+    VerifiedNode = verify_if_node_is_default(Node),
+    {NewTraffic, NewViz} = handle_incoming_node_info(VerifiedNode,
+                                                         Proplist,
+                                                         OldTraffic,
+                                                         OldMsgPass,
+                                                         OldViz,
+                                                         Subs),
+    {noreply, State#state{traffic = NewTraffic, viz_map = NewViz}};
 handle_info(Request, _State) ->
     exit({not_implemented, Request}).
 
-
 terminate(_Reason, _State) ->
     ok.
 
@@ -94,7 +90,61 @@ code_change(_OldVsn, State, _Extra) ->
 %%%===================================================================
 %%% Internal functions
 %%%===================================================================
-get_message_passing_counters(Node, Proplist, Vizceral, OldMsgPass) ->
+verify_subscribe_reply(Reply) ->
+    lists:all(fun(R) -> R =:= ok end, Reply).
+
+verify_if_node_is_default(Node) ->
+    verify_if_node_is_default(Node, epl:get_default_node()).
+
+verify_if_node_is_default(Node, DefaultNode)
+  when Node =:= DefaultNode ->
+    {true, Node};
+verify_if_node_is_default(Node, _DefaultNode) ->
+    {false, Node}.
+
+handle_incoming_node_info({false, _Node}, _Proplist, OldTraffic, _OldMsgPass,
+                          OldViz = undefined, _Subs) ->
+    {OldTraffic, OldViz};
+handle_incoming_node_info({true, Node}, Proplist, OldTraffic,
+                          OldMsgPass, OldViz, Subs) ->
+    {Viz1, NewTraffic} = update_traffic_graph(Node, OldTraffic,
+                                              epl_viz_map:new(Node)),
+    Viz2 = merge_existing_focused_nodes_and_conns(Viz1, OldViz),
+    %% We're starting from observed node which is our graph entry point
+    Viz3 = update_message_passing_counters(Node, Proplist, Viz2, OldMsgPass),
+    %% push an update to all subscribed WebSockets
+    JSON = epl_json:encode(Viz3, <<"traffic-info">>),
+
+    [Pid ! {data, JSON} || Pid <- Subs],
+    {NewTraffic, Viz3};
+handle_incoming_node_info({false, Node}, Proplist, OldTraffic,
+                          OldMsgPass, OldViz, _Subs) ->
+    %% We're starting from observed node which is our graph entry point
+    Viz1 = update_message_passing_counters(Node, Proplist, OldViz, OldMsgPass),
+    {OldTraffic, Viz1}.
+
+merge_existing_focused_nodes_and_conns(Viz, undefined) ->
+    Viz;
+merge_existing_focused_nodes_and_conns(Viz = #{nodes := Nodes}, OldViz) ->
+    lists:foldl(fun(Node, NewViz) ->
+                        maybe_merge_focused_nodes_and_conns(Node, NewViz, OldViz)
+                end, Viz, Nodes).
+maybe_merge_focused_nodes_and_conns(#{name := Node}, Viz, OldViz) ->
+    {Region, _} = epl_viz_map:pull_region(Node, OldViz),
+    finally_merge_focused_nodes_and_conns(Node, Viz, Region).
+
+finally_merge_focused_nodes_and_conns(_Node, Viz, []) ->
+    Viz;
+finally_merge_focused_nodes_and_conns(Node, Viz, Region) ->
+    {_, Viz2 = #{nodes := Regions}} = epl_viz_map:pull_region(Node, Viz),
+    finally_merge_regions(Viz2, Region, Regions).
+
+finally_merge_regions(Viz, UpdatedRegion, Regions) ->
+    maps:merge(Viz, #{nodes => [UpdatedRegion | Regions]}).
+
+update_message_passing_counters(Node, Proplist, Vizceral, OldMsgPass) ->
+    VizceralCleared =
+        epl_viz_map:clear_focused_nodes_and_conns_inside_region(Node, Vizceral),
     lists:foldl(
       fun({send, Send}, V) ->
               %% Examples of send trace:
@@ -105,13 +155,12 @@ get_message_passing_counters(Node, Proplist, Vizceral, OldMsgPass) ->
          (_, V) ->
               V
       end,
-      Vizceral,
+      VizceralCleared,
       Proplist).
 
 update_message_passing_graph(Node, Send, Vizceral, _OldMsgPass) ->
     %% the INTERNET node represents the source of ingress traffic
     Vizceral1 = epl_viz_map:push_focused(<<"INTERNET">>, Node, Vizceral),
-
     lists:foldl(
       fun({{ID1, ID2}, Count1, Count2}, V) ->
               P1 = get_PID_from_trace_event(ID1),

apps/epl/src/epl_viz_map.erl

@@ -19,6 +19,7 @@
          push_focused/4,
          push_focused_connection/5,
          push_focused_connection/6,
+         clear_focused_nodes_and_conns_inside_region/2,
          binarify/1,
          namify/1]).
 
@@ -78,11 +79,12 @@ push_node(Renderer, Name, Additional, Entity) ->
 -spec pull_node(Name :: name(), Entity :: map()) -> {map(), list()}.
 pull_node(Name, Entity) ->
     #{nodes := Nodes} = Entity,
-    {[Node], Rest} = lists:partition(
+    {Node, Rest} = lists:partition(
                        fun(A) ->
                                maps:get(name, A) == namify(Name)
                        end, Nodes),
-    {Node, Rest}.
+    VerifiedNode = verify_if_pulled_node_exists(Node),
+    {VerifiedNode, Rest}.
 
 %% @doc Pushes additional `Info' into cluster nodes section in `Vizceral' map.
 -spec push_additional_node_info(Info :: map(), Name :: atom(),
@@ -144,6 +146,16 @@ push_focused_connection(Source, Target, RegionName, {N, W, D}, A, Vizceral) ->
     NewR = push_connection(Source, Target, {N,W,D}, A, Region),
     push_region(RegionName, NewR, NewV).
 
+%% @doc Clears all focused nodes and connections from `RegionName` node.
+-spec clear_focused_nodes_and_conns_inside_region(RegionName :: name(), Viz :: map()) ->
+  map().
+clear_focused_nodes_and_conns_inside_region(RegionName, Viz) ->
+    {VizNode, NewViz = #{nodes := VizNodes}} =
+        epl_viz_map:pull_region(RegionName, Viz),
+    VizNodeCleared = maps:merge(VizNode, #{nodes => []}),
+    VizNodeCleared2 = maps:merge(VizNodeCleared, #{connections => []}),
+    maps:merge(NewViz, #{nodes => [VizNodeCleared2 | VizNodes]}).
+
 %%----------------------- Names -----------------------
 %% @doc Transforms `Name' to binary.
 -spec binarify(Name :: name()) -> binary().
@@ -186,3 +198,6 @@ entity(Renderer, Name, Nodes, Additional) ->
       nodes => Nodes
      },
     maps:merge(Map, Additional).
+
+verify_if_pulled_node_exists([]) -> [];
+verify_if_pulled_node_exists([Node]) -> Node.

apps/epl_ets/src/epl_ets_viz_map.erl

@@ -27,13 +27,15 @@ update_cluster(Node, Viz = #{nodes := VizNodes}) ->
 %% @doc Updates the Vizceral map's ETS details section.
 -spec update_details(Node :: node(), [] | list(), Viz :: map()) -> map().
 update_details(Node, [], Viz) ->
-    VizCleaned = clean_ets_traffic_from_viz(Node, Viz),
-    push_ets_tables(undefined, Node, [], VizCleaned);
+    VizCleared = epl_viz_map:clear_focused_nodes_and_conns_inside_region(Node,
+                                                                         Viz),
+    push_ets_tables(undefined, Node, [], VizCleared);
 update_details(Node, ETSTrafficCounters, Viz) ->
-    VizCleaned = clean_ets_traffic_from_viz(Node, Viz),
+    VizCleared = epl_viz_map:clear_focused_nodes_and_conns_inside_region(Node,
+                                                                         Viz),
     {tab_traffic, ETSTraffic} =
         epl_ets_metric:get_ets_tab_traffic(ETSTrafficCounters),
-    push_tab_traffic(ETSTraffic, Node, VizCleaned).
+    push_tab_traffic(ETSTraffic, Node, VizCleared).
 
 %% @doc Removes outdated nodes from Vizceral map's cluster section.
 -spec remove_outdated(Nodes :: [#{atom() => integer()}], Viz :: map()) -> map().
@@ -109,13 +111,6 @@ ensure_traffic_metrics_are_num(undefined, undefined) ->
 ensure_traffic_metrics_are_num(Insert, Lookup) ->
     {Insert, Lookup}.
 
-clean_ets_traffic_from_viz(Node, Viz) ->
-    {VizNode, NewViz = #{nodes := VizNodes}} = epl_viz_map:pull_region(Node,
-                                                                       Viz),
-    VizNodeCleaned = maps:merge(VizNode, #{nodes => []}),
-    VizNodeCleaned2 = maps:merge(VizNodeCleaned, #{connections => []}),
-    maps:merge(NewViz, #{nodes => [VizNodeCleaned2 | VizNodes]}).
-
 get_node_ets_basic_info(Node) ->
     ETSCount = epl_ets_metric:get_node_ets_num(Node),
     ETSMemUsage = epl_ets_metric:get_node_ets_mem(Node),