From 901573c6a588dcdc1900184fe77d55a83398c569 Mon Sep 17 00:00:00 2001
From: tigercl <zhouzb@emqx.io>
Date: Sat, 22 Aug 2020 09:59:55 +0800
Subject: [PATCH] fix(topic-metrics): fix the issue that the corresponding data
 is not properly cleaned up when unregistering (#3679)

---
 src/emqx_mod_topic_metrics.erl | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/emqx_mod_topic_metrics.erl b/src/emqx_mod_topic_metrics.erl
index b5b4c24e6..813d8d059 100644
--- a/src/emqx_mod_topic_metrics.erl
+++ b/src/emqx_mod_topic_metrics.erl
@@ -247,7 +247,10 @@ handle_call({unregister, Topic}, _From, State = #state{speeds = Speeds}) ->
             {reply, ok, State};
         true ->
             ok = delete_counters(Topic),
-            {reply, ok, State#state{speeds = maps:remove(Topic, Speeds)}}
+            NSpeeds = lists:foldl(fun(Metric, Acc) ->
+                                      maps:remove({Topic, Metric}, Acc)
+                                  end, Speeds, ?TOPIC_METRICS),
+            {reply, ok, State#state{speeds = NSpeeds}}
     end;
 
 handle_call({get_rate, Topic, Metric}, _From, State = #state{speeds = Speeds}) ->
@@ -271,7 +274,7 @@ handle_info(ticking, State = #state{speeds = Speeds}) ->
     NSpeeds = maps:map(
             fun({Topic, Metric}, Speed) ->
                 case val(Topic, Metric) of
-                    {error, topic_not_found} -> maps:remove(Topic, Speeds);
+                    {error, topic_not_found} -> maps:remove({Topic, Metric}, Speeds);
                     Val -> calculate_speed(Val, Speed)
                 end
             end, Speeds),