diff --git a/src/endpoint/endpoint_buffer.erl b/src/endpoint/endpoint_buffer.erl
index ac5cc02..d69ce51 100644
--- a/src/endpoint/endpoint_buffer.erl
+++ b/src/endpoint/endpoint_buffer.erl
@@ -14,7 +14,7 @@
 %% 消息重发间隔
 -define(RETRY_INTERVAL, 5000).
 
--export([new/2, append/2, trigger_next/1, trigger_n/1, cleanup/1, ack/2, stat/1, resize/2]).
+-export([new/2, append/2, trigger_next/1, trigger_n/1, cleanup/1, recover_inflight/1, ack/2, stat/1, resize/2]).
 -export_type([buffer/0]).
 
 -record(buffer, {
@@ -110,10 +110,16 @@ stat(#buffer{acc_num = AccNum, tid = Tid, flight_num = FlightNum}) ->
         <<"inflight_num">> => FlightNum
     }.
 
--spec cleanup(Buffer :: #buffer{}) -> ok.
-cleanup(#buffer{timer_pid = TimerPid}) ->
+-spec cleanup(Buffer :: #buffer{}) -> #buffer{}.
+cleanup(Buffer = #buffer{timer_pid = TimerPid}) ->
     endpoint_timer:cleanup(TimerPid),
-    ok.
+    Buffer.
+
+-spec recover_inflight(Buffer :: #buffer{}) -> #buffer{}.
+recover_inflight(Buffer = #buffer{tid = Tid, timer_pid = TimerPid}) ->
+    endpoint_timer:cleanup(TimerPid),
+    reset_inflight(Tid, ets:first(Tid)),
+    Buffer#buffer{cursor = 0, flight_num = 0}.
 
 -spec resize(Buffer :: #buffer{}, WindowSize :: integer()) -> #buffer{}.
 resize(Buffer = #buffer{}, WindowSize) when is_integer(WindowSize), WindowSize > 0 ->
@@ -145,3 +151,18 @@ next_pending_data_by_key(Tid, Key) ->
         [] ->
             next_pending_data_by_key(Tid, ets:next(Tid, Key))
     end.
+
+-spec reset_inflight(ets:tid(), '$end_of_table' | integer()) -> ok.
+reset_inflight(_Tid, '$end_of_table') ->
+    ok;
+reset_inflight(Tid, Key) ->
+    NextKey = ets:next(Tid, Key),
+    case ets:lookup(Tid, Key) of
+        [#north_data{inflight = true} = NorthData] ->
+            true = ets:insert(Tid, NorthData#north_data{inflight = false});
+        [_] ->
+            ok;
+        [] ->
+            ok
+    end,
+    reset_inflight(Tid, NextKey).
diff --git a/src/endpoint/endpoint_http.erl b/src/endpoint/endpoint_http.erl
index 8b85746..5bc991a 100644
--- a/src/endpoint/endpoint_http.erl
+++ b/src/endpoint/endpoint_http.erl
@@ -86,8 +86,8 @@ handle_cast({reload, NEndpoint = #endpoint{matcher = NMatcher, config = #http_en
     {noreply, State#state{endpoint = NEndpoint, buffer = NBuffer}};
 
 handle_cast(cleanup, State = #state{buffer = Buffer}) ->
-    endpoint_buffer:cleanup(Buffer),
-    {noreply, State}.
+    NBuffer = endpoint_buffer:cleanup(Buffer),
+    {noreply, State#state{buffer = NBuffer}}.
 
 %% @private
 %% @doc Handling all non call/cast messages
@@ -126,7 +126,7 @@ handle_info({next_data, Id, {Metric, Sign}}, State = #state{buffer = Buffer, end
 -spec(terminate(Reason :: (normal | shutdown | {shutdown, term()} | term()),
     State :: #state{}) -> term()).
 terminate(_Reason, #state{buffer = Buffer}) ->
-    endpoint_buffer:cleanup(Buffer),
+    _ = endpoint_buffer:cleanup(Buffer),
     ok.
 
 %% @private
diff --git a/src/endpoint/endpoint_kafka.erl b/src/endpoint/endpoint_kafka.erl
index 35264c5..08c5c9d 100644
--- a/src/endpoint/endpoint_kafka.erl
+++ b/src/endpoint/endpoint_kafka.erl
@@ -92,6 +92,7 @@ connected(cast, {reload, NEndpoint = #endpoint{matcher = NMatcher}},
     reload_endpoint(Matcher, NMatcher, ClientId, NEndpoint, State);
 connected(info, {next_data, Id, Metric},
           State = #state{
+              buffer = Buffer,
               client_pid = ClientPid,
               client_id = ClientId,
               endpoint = #endpoint{config = #kafka_endpoint{topic = Topic}}
@@ -109,20 +110,23 @@ connected(info, {next_data, Id, Metric},
         {error, Reason} ->
             logger:warning("[endpoint_kafka] produce topic: ~p, get error: ~p", [Topic, Reason]),
             stop_kafka_client(ClientId),
-            {next_state, disconnected, State#state{client_pid = undefined},
+            NBuffer = endpoint_buffer:recover_inflight(Buffer),
+            {next_state, disconnected, State#state{client_pid = undefined, buffer = NBuffer},
              [{state_timeout, ?RETRY_INTERVAL, connect}]};
         {'EXIT', Reason} ->
             logger:warning("[endpoint_kafka] produce topic: ~p, exit with reason: ~p", [Topic, Reason]),
             stop_kafka_client(ClientId),
-            {next_state, disconnected, State#state{client_pid = undefined},
+            NBuffer = endpoint_buffer:recover_inflight(Buffer),
+            {next_state, disconnected, State#state{client_pid = undefined, buffer = NBuffer},
              [{state_timeout, ?RETRY_INTERVAL, connect}]}
     end;
 connected(info, {ack, Id}, State = #state{buffer = Buffer}) ->
     ack_buffer(Id, Buffer, State);
 connected(info, {'EXIT', ClientPid, Reason},
-          State = #state{client_pid = ClientPid, endpoint = #endpoint{title = Title}}) ->
+          State = #state{client_pid = ClientPid, endpoint = #endpoint{title = Title}, buffer = Buffer}) ->
     logger:warning("[endpoint_kafka] endpoint: ~p, conn pid exit with reason: ~p", [Title, Reason]),
-    {next_state, disconnected, State#state{client_pid = undefined},
+    NBuffer = endpoint_buffer:recover_inflight(Buffer),
+    {next_state, disconnected, State#state{client_pid = undefined, buffer = NBuffer},
      [{state_timeout, ?RETRY_INTERVAL, connect}]};
 connected(info, Info, State) ->
     unknown_info(Info, connected, State);
@@ -160,8 +164,8 @@ forward_metric(Metric, Buffer, State) ->
 -spec cleanup_buffer(endpoint_buffer:buffer(), #state{}) ->
     gen_statem:event_handler_result(kafka_state(), #state{}).
 cleanup_buffer(Buffer, _State) ->
-    endpoint_buffer:cleanup(Buffer),
-    keep_state_and_data.
+    NBuffer = endpoint_buffer:cleanup(Buffer),
+    {keep_state, _State#state{buffer = NBuffer}}.
 
 -spec ack_buffer(integer(), endpoint_buffer:buffer(), #state{}) ->
     gen_statem:event_handler_result(kafka_state(), #state{}).
@@ -174,7 +178,8 @@ ack_buffer(Id, Buffer, State) ->
 reload_endpoint(Matcher, NMatcher, ClientId, NEndpoint, State = #state{}) ->
     ensure_subscription(Matcher, NMatcher),
     stop_kafka_client(ClientId),
-    {next_state, disconnected, State#state{endpoint = NEndpoint, client_pid = undefined},
+    NBuffer = endpoint_buffer:recover_inflight(State#state.buffer),
+    {next_state, disconnected, State#state{endpoint = NEndpoint, client_pid = undefined, buffer = NBuffer},
      [{state_timeout, 0, connect}]}.
 
 -spec try_connect(#state{}) -> gen_statem:event_handler_result(kafka_state(), #state{}).
diff --git a/src/endpoint/endpoint_mqtt.erl b/src/endpoint/endpoint_mqtt.erl
index de6b4aa..d5ee42b 100644
--- a/src/endpoint/endpoint_mqtt.erl
+++ b/src/endpoint/endpoint_mqtt.erl
@@ -152,13 +152,16 @@ connected(info, {next_data, Id, Metric},
         {error, Reason} ->
             logger:warning("[endpoint_mqtt] send message to topic: ~p, get error: ~p", [Topic, Reason]),
             stop_mqtt_conn(ConnPid),
-            {next_state, disconnected, State#state{conn_pid = undefined, inflight = #{}},
+            NBuffer = endpoint_buffer:recover_inflight(Buffer),
+            {next_state, disconnected, State#state{conn_pid = undefined, inflight = #{}, buffer = NBuffer},
              [{state_timeout, ?RETRY_INTERVAL, connect}]}
     end;
-connected(info, {disconnected, ReasonCode, Properties}, State = #state{conn_pid = ConnPid}) ->
+connected(info, {disconnected, ReasonCode, Properties},
+          State = #state{conn_pid = ConnPid, buffer = Buffer}) ->
     logger:debug("[endpoint_mqtt] Recv a DISONNECT packet - ReasonCode: ~p, Properties: ~p", [ReasonCode, Properties]),
     stop_mqtt_conn(ConnPid),
-    {next_state, disconnected, State#state{conn_pid = undefined, inflight = #{}},
+    NBuffer = endpoint_buffer:recover_inflight(Buffer),
+    {next_state, disconnected, State#state{conn_pid = undefined, inflight = #{}, buffer = NBuffer},
      [{state_timeout, ?RETRY_INTERVAL, connect}]};
 connected(info, {publish, Message = #{packet_id := _PacketId, payload := Payload}}, State) ->
     logger:debug("[endpoint_mqtt] Recv a publish packet: ~p, payload: ~p", [Message, Payload]),
@@ -173,9 +176,10 @@ connected(info, {puback, #{packet_id := PacketId}},
             {keep_state, State}
     end;
 connected(info, {'EXIT', ConnPid, Reason},
-          State = #state{endpoint = #endpoint{title = Title}, conn_pid = ConnPid}) ->
+          State = #state{endpoint = #endpoint{title = Title}, conn_pid = ConnPid, buffer = Buffer}) ->
     logger:warning("[endpoint_mqtt] endpoint: ~p, conn pid exit with reason: ~p", [Title, Reason]),
-    {next_state, disconnected, State#state{conn_pid = undefined, inflight = #{}},
+    NBuffer = endpoint_buffer:recover_inflight(Buffer),
+    {next_state, disconnected, State#state{conn_pid = undefined, inflight = #{}, buffer = NBuffer},
      [{state_timeout, ?RETRY_INTERVAL, connect}]};
 connected(info, Info, State) ->
     unknown_info(Info, connected, State);
@@ -212,16 +216,17 @@ forward_metric(Metric, Buffer, State) ->
 
 -spec cleanup_buffer(endpoint_buffer:buffer(), #state{}) ->
     gen_statem:event_handler_result(mqtt_state(), #state{}).
-cleanup_buffer(Buffer, _State) ->
-    endpoint_buffer:cleanup(Buffer),
-    keep_state_and_data.
+cleanup_buffer(Buffer, State) ->
+    NBuffer = endpoint_buffer:cleanup(Buffer),
+    {keep_state, State#state{buffer = NBuffer}}.
 
 -spec reload_endpoint(binary(), binary(), undefined | pid(), #endpoint{}, #state{}) ->
     gen_statem:event_handler_result(mqtt_state(), #state{}).
 reload_endpoint(Matcher, NMatcher, ConnPid, NEndpoint, State = #state{}) ->
     ensure_subscription(Matcher, NMatcher),
     stop_mqtt_conn(ConnPid),
-    {next_state, disconnected, State#state{endpoint = NEndpoint, conn_pid = undefined, inflight = #{}},
+    NBuffer = endpoint_buffer:recover_inflight(State#state.buffer),
+    {next_state, disconnected, State#state{endpoint = NEndpoint, conn_pid = undefined, inflight = #{}, buffer = NBuffer},
      [{next_event, internal, do_connect}]}.
 
 -spec unknown_info(term(), mqtt_state(), #state{}) ->