diff --git a/.github/workflows/run_cts_tests.yaml b/.github/workflows/run_cts_tests.yaml
index cfcb7baca..b89c6e10a 100644
--- a/.github/workflows/run_cts_tests.yaml
+++ b/.github/workflows/run_cts_tests.yaml
@@ -24,6 +24,11 @@ jobs:
 
     steps:
       - uses: actions/checkout@v1
+        # to avoid dirty self-hosted runners
+      - name: stop containers
+        run: |
+          docker rm -f $(docker ps -qa) || true
+          docker network rm $(docker network ls -q) || true
       - name: docker compose up
         env:
           LDAP_TAG: ${{ matrix.ldap_tag }}
@@ -79,6 +84,10 @@ jobs:
 
     steps:
       - uses: actions/checkout@v1
+      - name: stop containers
+        run: |
+          docker rm -f $(docker ps -qa) || true
+          docker network rm $(docker network ls -q) || true
       - name: docker-compose up
         run: |
           docker-compose \
@@ -151,6 +160,10 @@ jobs:
 
     steps:
       - uses: actions/checkout@v1
+      - name: stop containers
+        run: |
+          docker rm -f $(docker ps -qa) || true
+          docker network rm $(docker network ls -q) || true
       - name: docker-compose up
         timeout-minutes: 5
         run: |
@@ -237,6 +250,10 @@ jobs:
         - tcp
     steps:
       - uses: actions/checkout@v1
+      - name: stop containers
+        run: |
+          docker rm -f $(docker ps -qa) || true
+          docker network rm $(docker network ls -q) || true
       - name: docker-compose up
         run: |
           docker-compose \
@@ -318,6 +335,10 @@ jobs:
 
     steps:
       - uses: actions/checkout@v1
+      - name: stop containers
+        run: |
+          docker rm -f $(docker ps -qa) || true
+          docker network rm $(docker network ls -q) || true
       - name: docker-compose up
         run: |
           docker-compose \
diff --git a/.github/workflows/run_test_cases.yaml b/.github/workflows/run_test_cases.yaml
index 6f42730ea..5f98f6940 100644
--- a/.github/workflows/run_test_cases.yaml
+++ b/.github/workflows/run_test_cases.yaml
@@ -42,6 +42,11 @@ jobs:
                 use-self-hosted: false
         steps:
         - uses: actions/checkout@v2
+          # to avoid dirty self-hosted runners
+        - name: stop containers
+          run: |
+            docker rm -f $(docker ps -qa) || true
+            docker network rm $(docker network ls -q) || true
         - name: docker compose up
           if: endsWith(github.repository, 'emqx')
           env:
diff --git a/CHANGES-4.3.md b/CHANGES-4.3.md
index 6b0d0c4e9..13efa6369 100644
--- a/CHANGES-4.3.md
+++ b/CHANGES-4.3.md
@@ -32,8 +32,18 @@ File format:
 - Added a test to prevent a last will testament message to be
   published when a client is denied connection. [#8894](https://github.com/emqx/emqx/pull/8894)
 
+- More rigorous checking of flapping to improve stability of the system. [#9045](https://github.com/emqx/emqx/pull/9045)
+
+- QoS1 and QoS2 messages in session's buffer are re-dispatched to other members in the group
+  when the session terminates [#9094](https://github.com/emqx/emqx/pull/9094).
+  Prior to this enhancement, one would have to set `broker.shared_dispatch_ack_enabled` to true
+  to prevent sessions from buffering messages, however this acknowledgement comes with a cost.
+
+
 ### Bug fixes
 
+- Fix HTTP client library to handle SSL socket passive signal. [#9145](https://github.com/emqx/emqx/pull/9145)
+
 - Fix delayed publish inaccurate caused by os time change. [#8908](https://github.com/emqx/emqx/pull/8908)
 
 - Hide redis password in error logs [#9071](https://github.com/emqx/emqx/pull/9071)
@@ -48,6 +58,26 @@ File format:
     Same `format_status` callback is added here too for `gen_server`s which hold password in
     their state.
 
+- Fix shared subscription message re-dispatches [#9094](https://github.com/emqx/emqx/pull/9094).
+  - When discarding QoS 2 inflight messages, there were excessive logs
+  - For wildcard deliveries, the re-dispatch used the wrong topic (the publishing topic,
+    but not the subscribing topic), caused messages to be lost when dispatching.
+
+- Fix shared subscription group member unsubscribe issue when 'sticky' strategy is used.
+  Prior to this fix, if a previously picked member unsubscribes from the group (without reconnect)
+  the message is still dispatched to it.
+  This issue only occurs when unsubscribe with the session kept.
+  Fixed in [#9119](https://github.com/emqx/emqx/pull/9119)
+
+- Fix shared subscription 'sticky' strategy when there is no local subscriptions at all.
+  Prior to this change, it may take a few rounds to randomly pick group members until a local subscriber
+  is hit (and then start sticking to it).
+  After this fix, it will start sticking to whichever randomly picked member even when it is a
+  subscriber from another node in the cluster.
+  Fixed in [#9122](https://github.com/emqx/emqx/pull/9122)
+
+- Fix cannot reset metrics for fallback actions. [#9125](https://github.com/emqx/emqx/pull/9125)
+
 ## v4.3.20
 
 ### Bug fixes
diff --git a/CHANGES-4.4.md b/CHANGES-4.4.md
index 16d57a37c..7228ad22b 100644
--- a/CHANGES-4.4.md
+++ b/CHANGES-4.4.md
@@ -1,8 +1,14 @@
 # EMQX 4.4 Changes
 
+## v4.4.11
+
+### Bug fixes  (synced from v4.3.22)
+
+### Enhancements (synced from v4.3.22)
+
 ## v4.4.10
 
-### Bug fixes
+### Bug fixes  (synced from v4.3.21)
 
 - Fix the latency statistics error of the slow subscription module when `stats_type` is `internal` or `response`. [#8981](https://github.com/emqx/emqx/pull/8981)
 
diff --git a/apps/emqx_auth_http/include/emqx_auth_http.hrl b/apps/emqx_auth_http/include/emqx_auth_http.hrl
index 0eaa59daf..4e659293f 100644
--- a/apps/emqx_auth_http/include/emqx_auth_http.hrl
+++ b/apps/emqx_auth_http/include/emqx_auth_http.hrl
@@ -1 +1,20 @@
+%%--------------------------------------------------------------------
+%% Copyright (c) 2020-2022 EMQ Technologies Co., Ltd. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%--------------------------------------------------------------------
+
 -define(APP, emqx_auth_http).
+
+%% equals to the default value of ehttpc
+-define(DEFAULT_RETRY_TIMES, 2).
diff --git a/apps/emqx_auth_http/src/emqx_acl_http.erl b/apps/emqx_auth_http/src/emqx_acl_http.erl
index d4fd96a95..51bf9c303 100644
--- a/apps/emqx_auth_http/src/emqx_acl_http.erl
+++ b/apps/emqx_auth_http/src/emqx_acl_http.erl
@@ -24,7 +24,7 @@
 -logger_header("[ACL http]").
 
 -import(emqx_auth_http_cli,
-        [ request/6
+        [ request/7
         , feedvar/2
         ]).
 
@@ -56,13 +56,15 @@ description() -> "ACL with HTTP API".
 %% Internal functions
 %%--------------------------------------------------------------------
 
-check_acl_request(#{pool_name := PoolName,
+check_acl_request(ACLParams =
+                  #{pool_name := PoolName,
                     path := Path,
                     method := Method,
                     headers := Headers,
                     params := Params,
                     timeout := Timeout}, ClientInfo) ->
-    request(PoolName, Method, Path, Headers, feedvar(Params, ClientInfo), Timeout).
+    Retry = maps:get(retry_times, ACLParams, ?DEFAULT_RETRY_TIMES),
+    request(PoolName, Method, Path, Headers, feedvar(Params, ClientInfo), Timeout, Retry).
 
 access(subscribe) -> 1;
 access(publish)   -> 2.
diff --git a/apps/emqx_auth_http/src/emqx_auth_http.app.src b/apps/emqx_auth_http/src/emqx_auth_http.app.src
index e943317f8..87d087bae 100644
--- a/apps/emqx_auth_http/src/emqx_auth_http.app.src
+++ b/apps/emqx_auth_http/src/emqx_auth_http.app.src
@@ -1,6 +1,6 @@
 {application, emqx_auth_http,
  [{description, "EMQ X Authentication/ACL with HTTP API"},
-  {vsn, "4.3.7"}, % strict semver, bump manually!
+  {vsn, "4.3.8"}, % strict semver, bump manually!
   {modules, []},
   {registered, [emqx_auth_http_sup]},
   {applications, [kernel,stdlib,ehttpc]},
diff --git a/apps/emqx_auth_http/src/emqx_auth_http.appup.src b/apps/emqx_auth_http/src/emqx_auth_http.appup.src
index f5c2bfe42..01d756b9e 100644
--- a/apps/emqx_auth_http/src/emqx_auth_http.appup.src
+++ b/apps/emqx_auth_http/src/emqx_auth_http.appup.src
@@ -1,17 +1,27 @@
 %% -*- mode: erlang -*-
+%% Unless you know what you are doing, DO NOT edit manually!!
 {VSN,
-  [{"4.3.6",
-    [ %% There are only changes to the schema file, so we don't need any
-      %% commands here
-    ]},
+  [{"4.3.7",
+    [{load_module,emqx_auth_http_cli,brutal_purge,soft_purge,[]},
+     {load_module,emqx_auth_http,brutal_purge,soft_purge,[]},
+     {load_module,emqx_acl_http,brutal_purge,soft_purge,[]}]},
+   {"4.3.6",
+    [{load_module,emqx_auth_http_cli,brutal_purge,soft_purge,[]},
+     {load_module,emqx_auth_http,brutal_purge,soft_purge,[]},
+     {load_module,emqx_acl_http,brutal_purge,soft_purge,[]}]},
    {"4.3.5",
-    [{load_module,emqx_auth_http_app,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_auth_http_cli,brutal_purge,soft_purge,[]},
+     {load_module,emqx_acl_http,brutal_purge,soft_purge,[]},
+     {load_module,emqx_auth_http_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_auth_http,brutal_purge,soft_purge,[]}]},
    {"4.3.4",
-    [{load_module,emqx_auth_http_app,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_auth_http_cli,brutal_purge,soft_purge,[]},
+     {load_module,emqx_acl_http,brutal_purge,soft_purge,[]},
+     {load_module,emqx_auth_http_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_auth_http,brutal_purge,soft_purge,[]}]},
    {"4.3.3",
-    [{load_module,emqx_auth_http_app,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_auth_http_cli,brutal_purge,soft_purge,[]},
+     {load_module,emqx_auth_http_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_auth_http,brutal_purge,soft_purge,[]},
      {load_module,emqx_acl_http,brutal_purge,soft_purge,[]}]},
    {"4.3.2",
@@ -20,21 +30,29 @@
      {load_module,emqx_auth_http,brutal_purge,soft_purge,[]},
      {load_module,emqx_acl_http,brutal_purge,soft_purge,[]},
      {load_module,emqx_auth_http_cli,brutal_purge,soft_purge,[]}]},
-   {<<"4.3.[0-1]">>,
-    [{restart_application,emqx_auth_http}]},
+   {<<"4.3.[0-1]">>,[{restart_application,emqx_auth_http}]},
    {<<".*">>,[]}],
-  [{"4.3.6",
-    [ %% There are only changes to the schema file, so we don't need any
-      %% commands here
-    ]},
+  [{"4.3.7",
+    [{load_module,emqx_auth_http_cli,brutal_purge,soft_purge,[]},
+     {load_module,emqx_auth_http,brutal_purge,soft_purge,[]},
+     {load_module,emqx_acl_http,brutal_purge,soft_purge,[]}]},
+   {"4.3.6",
+    [{load_module,emqx_auth_http_cli,brutal_purge,soft_purge,[]},
+     {load_module,emqx_auth_http,brutal_purge,soft_purge,[]},
+     {load_module,emqx_acl_http,brutal_purge,soft_purge,[]}]},
    {"4.3.5",
-    [{load_module,emqx_auth_http_app,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_auth_http_cli,brutal_purge,soft_purge,[]},
+     {load_module,emqx_acl_http,brutal_purge,soft_purge,[]},
+     {load_module,emqx_auth_http_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_auth_http,brutal_purge,soft_purge,[]}]},
    {"4.3.4",
-    [{load_module,emqx_auth_http_app,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_auth_http_cli,brutal_purge,soft_purge,[]},
+     {load_module,emqx_acl_http,brutal_purge,soft_purge,[]},
+     {load_module,emqx_auth_http_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_auth_http,brutal_purge,soft_purge,[]}]},
    {"4.3.3",
-    [{load_module,emqx_auth_http_app,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_auth_http_cli,brutal_purge,soft_purge,[]},
+     {load_module,emqx_auth_http_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_auth_http,brutal_purge,soft_purge,[]},
      {load_module,emqx_acl_http,brutal_purge,soft_purge,[]}]},
    {"4.3.2",
@@ -43,6 +61,5 @@
      {load_module,emqx_auth_http,brutal_purge,soft_purge,[]},
      {load_module,emqx_acl_http,brutal_purge,soft_purge,[]},
      {load_module,emqx_auth_http_cli,brutal_purge,soft_purge,[]}]},
-   {<<"4.3.[0-1]">>,
-    [{restart_application,emqx_auth_http}]},
+   {<<"4.3.[0-1]">>,[{restart_application,emqx_auth_http}]},
    {<<".*">>,[]}]}.
diff --git a/apps/emqx_auth_http/src/emqx_auth_http.erl b/apps/emqx_auth_http/src/emqx_auth_http.erl
index 98a897a8c..620750bd0 100644
--- a/apps/emqx_auth_http/src/emqx_auth_http.erl
+++ b/apps/emqx_auth_http/src/emqx_auth_http.erl
@@ -25,7 +25,7 @@
 -logger_header("[Auth http]").
 
 -import(emqx_auth_http_cli,
-        [ request/6
+        [ request/7
         , feedvar/2
         ]).
 
@@ -63,24 +63,28 @@ description() -> "Authentication by HTTP API".
 %% Requests
 %%--------------------------------------------------------------------
 
-authenticate(#{pool_name := PoolName,
+authenticate(AuthParams =
+             #{pool_name := PoolName,
                path := Path,
                method := Method,
                headers := Headers,
                params := Params,
                timeout := Timeout}, ClientInfo) ->
-   request(PoolName, Method, Path, Headers, feedvar(Params, ClientInfo), Timeout).
+    Retry = maps:get(retry_times, AuthParams, ?DEFAULT_RETRY_TIMES),
+    request(PoolName, Method, Path, Headers, feedvar(Params, ClientInfo), Timeout, Retry).
 
 -spec(is_superuser(maybe(map()), emqx_types:client()) -> boolean()).
 is_superuser(undefined, _ClientInfo) ->
     false;
-is_superuser(#{pool_name := PoolName,
+is_superuser(SuperParams =
+             #{pool_name := PoolName,
                path := Path,
                method := Method,
                headers := Headers,
                params := Params,
                timeout := Timeout}, ClientInfo) ->
-    case request(PoolName, Method, Path, Headers, feedvar(Params, ClientInfo), Timeout) of
+    Retry = maps:get(retry_times, SuperParams, ?DEFAULT_RETRY_TIMES),
+    case request(PoolName, Method, Path, Headers, feedvar(Params, ClientInfo), Timeout, Retry) of
         {ok, 200, _Body}   -> true;
         {ok, _Code, _Body} -> false;
         {error, Error}     -> ?LOG(error, "Request superuser path ~s, error: ~p", [Path, Error]),
diff --git a/apps/emqx_auth_http/src/emqx_auth_http_cli.erl b/apps/emqx_auth_http/src/emqx_auth_http_cli.erl
index 3c7efd9c9..c747b778a 100644
--- a/apps/emqx_auth_http/src/emqx_auth_http_cli.erl
+++ b/apps/emqx_auth_http/src/emqx_auth_http_cli.erl
@@ -19,6 +19,7 @@
 -include("emqx_auth_http.hrl").
 
 -export([ request/6
+        , request/7
         , feedvar/2
         , feedvar/3
         ]).
@@ -27,18 +28,21 @@
 %% HTTP Request
 %%--------------------------------------------------------------------
 
-request(PoolName, get, Path, Headers, Params, Timeout) ->
-    NewPath = Path ++ "?" ++ binary_to_list(cow_qs:qs(bin_kw(Params))),
-    reply(ehttpc:request(PoolName, get, {NewPath, Headers}, Timeout));
+request(PoolName, Method, Path, Headers, Params, Timeout) ->
+    request(PoolName, Method, Path, Headers, Params, Timeout, ?DEFAULT_RETRY_TIMES).
 
-request(PoolName, post, Path, Headers, Params, Timeout) ->
+request(PoolName, get, Path, Headers, Params, Timeout, Retry) ->
+    NewPath = Path ++ "?" ++ binary_to_list(cow_qs:qs(bin_kw(Params))),
+    reply(ehttpc:request(PoolName, get, {NewPath, Headers}, Timeout, Retry));
+
+request(PoolName, post, Path, Headers, Params, Timeout, Retry) ->
     Body = case proplists:get_value(<<"content-type">>, Headers) of
                "application/x-www-form-urlencoded" ->
                    cow_qs:qs(bin_kw(Params));
                "application/json" -> 
                    emqx_json:encode(bin_kw(Params))
            end,
-    reply(ehttpc:request(PoolName, post, {Path, Headers, Body}, Timeout)).
+    reply(ehttpc:request(PoolName, post, {Path, Headers, Body}, Timeout, Retry)).
 
 reply({ok, StatusCode, _Headers}) ->
     {ok, StatusCode, <<>>};
diff --git a/apps/emqx_rule_engine/src/emqx_rule_engine.app.src b/apps/emqx_rule_engine/src/emqx_rule_engine.app.src
index 12753e62b..b02edb456 100644
--- a/apps/emqx_rule_engine/src/emqx_rule_engine.app.src
+++ b/apps/emqx_rule_engine/src/emqx_rule_engine.app.src
@@ -1,6 +1,6 @@
 {application, emqx_rule_engine,
  [{description, "EMQ X Rule Engine"},
-  {vsn, "4.4.10"}, % strict semver, bump manually!
+  {vsn, "4.4.11"}, % strict semver, bump manually!
   {modules, []},
   {registered, [emqx_rule_engine_sup, emqx_rule_registry]},
   {applications, [kernel,stdlib,rulesql,getopt]},
diff --git a/apps/emqx_rule_engine/src/emqx_rule_engine.appup.src b/apps/emqx_rule_engine/src/emqx_rule_engine.appup.src
index 004545793..6b880df7a 100644
--- a/apps/emqx_rule_engine/src/emqx_rule_engine.appup.src
+++ b/apps/emqx_rule_engine/src/emqx_rule_engine.appup.src
@@ -1,19 +1,24 @@
 %% -*- mode: erlang -*-
 %% Unless you know what you are doing, DO NOT edit manually!!
 {VSN,
-  [{"4.4.9",
+  [{"4.4.10",
+    [{load_module,emqx_rule_registry,brutal_purge,soft_purge,[]}]},
+   {"4.4.9",
     [{load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_registry,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_metrics,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine,brutal_purge,soft_purge,[]}]},
    {"4.4.8",
     [{load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_registry,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_runtime,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_metrics,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine,brutal_purge,soft_purge,[]}]},
    {<<"4\\.4\\.[6-7]">>,
-    [{load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_metrics,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_utils,brutal_purge,soft_purge,[]},
@@ -21,7 +26,8 @@
      {load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_registry,brutal_purge,soft_purge,[]}]},
    {"4.4.5",
-    [{load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_metrics,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_registry,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_utils,brutal_purge,soft_purge,[]},
@@ -30,7 +36,8 @@
      {load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]}]},
    {"4.4.4",
-    [{load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_metrics,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_utils,brutal_purge,soft_purge,[]},
@@ -39,7 +46,8 @@
      {load_module,emqx_rule_runtime,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_actions,brutal_purge,soft_purge,[]}]},
    {"4.4.3",
-    [{load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_metrics,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_utils,brutal_purge,soft_purge,[]},
@@ -97,19 +105,24 @@
      {load_module,emqx_rule_runtime,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]}]},
    {<<".*">>,[]}],
-  [{"4.4.9",
+  [{"4.4.10",
+    [{load_module,emqx_rule_registry,brutal_purge,soft_purge,[]}]},
+   {"4.4.9",
     [{load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_registry,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_metrics,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine,brutal_purge,soft_purge,[]}]},
    {"4.4.8",
     [{load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_registry,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_runtime,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_metrics,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine,brutal_purge,soft_purge,[]}]},
    {<<"4\\.4\\.[6-7]">>,
-    [{load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_metrics,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_utils,brutal_purge,soft_purge,[]},
@@ -117,7 +130,8 @@
      {load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_registry,brutal_purge,soft_purge,[]}]},
    {"4.4.5",
-    [{load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_metrics,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_registry,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_utils,brutal_purge,soft_purge,[]},
@@ -126,7 +140,8 @@
      {load_module,emqx_rule_runtime,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]}]},
    {"4.4.4",
-    [{load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_metrics,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_utils,brutal_purge,soft_purge,[]},
@@ -135,7 +150,8 @@
      {load_module,emqx_rule_runtime,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_actions,brutal_purge,soft_purge,[]}]},
    {"4.4.3",
-    [{load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_metrics,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_utils,brutal_purge,soft_purge,[]},
diff --git a/apps/emqx_rule_engine/src/emqx_rule_metrics.erl b/apps/emqx_rule_engine/src/emqx_rule_metrics.erl
index 4a532d00b..70049d277 100644
--- a/apps/emqx_rule_engine/src/emqx_rule_metrics.erl
+++ b/apps/emqx_rule_engine/src/emqx_rule_metrics.erl
@@ -133,16 +133,15 @@ clear_metrics(Id) ->
 -spec(reset_metrics(rule_id()) -> ok).
 reset_metrics(Id) ->
     reset_speeds(Id),
-    reset_metrics(Id, rule_metrics()),
+    do_reset_metrics(Id, rule_metrics()),
     case emqx_rule_registry:get_rule(Id) of
         not_found -> ok;
         {ok, #rule{actions = Actions}} ->
-            [ reset_metrics(ActionId, action_metrics())
-              || #action_instance{ id = ActionId} <- Actions],
+            reset_action_metrics(Actions),
             ok
     end.
 
-reset_metrics(Id, Metrics) ->
+do_reset_metrics(Id, Metrics) ->
     case couters_ref(Id) of
         not_found -> ok;
         Ref -> [counters:put(Ref, metrics_idx(Idx), 0)
@@ -150,6 +149,12 @@ reset_metrics(Id, Metrics) ->
                ok
     end.
 
+reset_action_metrics(Actions) ->
+    lists:foreach(fun(#action_instance{id = ActionId, fallbacks = FallbackActions}) ->
+            do_reset_metrics(ActionId, action_metrics()),
+            reset_action_metrics(FallbackActions)
+        end, Actions).
+
 reset_speeds(Id) ->
     gen_server:call(?MODULE, {reset_speeds, Id}).
 
@@ -330,6 +335,8 @@ handle_call({create_rule_metrics, Id}, _From,
                                     _ -> RuleSpeeds#{Id => #rule_speed{}}
                                 end}};
 
+handle_call({reset_speeds, _Id}, _From, State = #state{rule_speeds = undefined}) ->
+    {reply, ok, State};
 handle_call({reset_speeds, Id}, _From, State = #state{rule_speeds = RuleSpeedMap}) ->
     {reply, ok, State#state{rule_speeds = maps:put(Id, #rule_speed{}, RuleSpeedMap)}};
 
diff --git a/apps/emqx_rule_engine/test/emqx_rule_engine_SUITE.erl b/apps/emqx_rule_engine/test/emqx_rule_engine_SUITE.erl
index d819aa5e3..857b9017c 100644
--- a/apps/emqx_rule_engine/test/emqx_rule_engine_SUITE.erl
+++ b/apps/emqx_rule_engine/test/emqx_rule_engine_SUITE.erl
@@ -50,6 +50,7 @@ groups() ->
        t_unregister_provider,
        t_create_rule,
        t_reset_metrics,
+       t_reset_metrics_fallbacks,
        t_create_resource
       ]},
      {actions, [],
@@ -381,18 +382,14 @@ t_inspect_action(_Config) ->
 
 t_reset_metrics(_Config) ->
     ok = emqx_rule_engine:load_providers(),
-    {ok, #resource{id = ResId}} = emqx_rule_engine:create_resource(
-                                    #{type => built_in,
-                                      config => #{},
-                                      description => <<"debug resource">>}),
-    {ok, #rule{id = Id}} = emqx_rule_engine:create_rule(
-                             #{rawsql => "select clientid as c, username as u "
-                               "from \"t1\" ",
-                               actions => [#{name => 'inspect',
-                                             args => #{'$resource' => ResId, a=>1, b=>2}}],
-                               type => built_in,
-                               description => <<"Inspect rule">>
-                              }),
+    {ok, #rule{id = Id, actions = [#action_instance{id = ActId0}]}} =
+        emqx_rule_engine:create_rule(
+            #{rawsql => "select clientid as c, username as u "
+            "from \"t1\" ",
+            actions => [#{name => 'inspect', args => #{a=>1, b=>2}}],
+            type => built_in,
+            description => <<"Inspect rule">>
+            }),
     {ok, Client} = emqtt:start_link([{username, <<"emqx">>}]),
     {ok, _} = emqtt:connect(Client),
     [ begin
@@ -400,16 +397,68 @@ t_reset_metrics(_Config) ->
           timer:sleep(100)
       end
       || _ <- lists:seq(1,10)],
+    ?assertMatch(#{exception := 0, failed := 0,
+                   matched := 10, no_result := 0, passed := 10},
+                 emqx_rule_metrics:get_rule_metrics(Id)),
+    ?assertMatch(#{failed := 0, success := 10, taken := 10},
+                   emqx_rule_metrics:get_action_metrics(ActId0)),
     emqx_rule_metrics:reset_metrics(Id),
     ?assertEqual(#{exception => 0,failed => 0,
                    matched => 0,no_result => 0,passed => 0,
                    speed => 0.0,speed_last5m => 0.0,speed_max => 0.0},
                  emqx_rule_metrics:get_rule_metrics(Id)),
-    ?assertEqual(#{failed => 0,success => 0,taken => 0},
-                   emqx_rule_metrics:get_action_metrics(ResId)),
+    ?assertEqual(#{failed => 0, success => 0, taken => 0},
+                   emqx_rule_metrics:get_action_metrics(ActId0)),
     emqtt:stop(Client),
     emqx_rule_registry:remove_rule(Id),
-    emqx_rule_registry:remove_resource(ResId),
+    ok.
+
+t_reset_metrics_fallbacks(_Config) ->
+    ok = emqx_rule_engine:load_providers(),
+    ok = emqx_rule_registry:add_action(
+            #action{name = 'crash_action', app = ?APP,
+                    module = ?MODULE, on_create = crash_action,
+                    types=[], params_spec = #{},
+                    title = #{en => <<"Crash Action">>},
+                    description = #{en => <<"This action will always fail!">>}}),
+    {ok, #rule{id = Id, actions = [#action_instance{id = ActId0, fallbacks = [
+            #action_instance{id = ActId1},
+            #action_instance{id = ActId2}
+        ]}]}} =
+        emqx_rule_engine:create_rule(
+            #{rawsql => "select clientid as c, username as u "
+            "from \"t1\" ",
+            actions => [#{name => 'crash_action', args => #{a=>1, b=>2}, fallbacks => [
+                              #{name => 'inspect', args => #{}, fallbacks => []},
+                              #{name => 'inspect', args => #{}, fallbacks => []}
+                          ]}],
+            type => built_in,
+            description => <<"Inspect rule">>
+            }),
+    {ok, Client} = emqtt:start_link([{username, <<"emqx">>}]),
+    {ok, _} = emqtt:connect(Client),
+    [ begin
+          emqtt:publish(Client, <<"t1">>, <<"{\"id\": 1, \"name\": \"ha\"}">>, 0),
+          timer:sleep(100)
+      end
+      || _ <- lists:seq(1,10)],
+    ?assertMatch(#{exception := 0, failed := 0,
+                   matched := 10, no_result := 0, passed := 10},
+                 emqx_rule_metrics:get_rule_metrics(Id)),
+    [?assertMatch(#{failed := 10, success := 0, taken := 10},
+                   emqx_rule_metrics:get_action_metrics(AId)) || AId <- [ActId0]],
+    [?assertMatch(#{failed := 0, success := 10, taken := 10},
+                   emqx_rule_metrics:get_action_metrics(AId)) || AId <- [ ActId1, ActId2]],
+    emqx_rule_metrics:reset_metrics(Id),
+    ?assertEqual(#{exception => 0,failed => 0,
+                   matched => 0,no_result => 0,passed => 0,
+                   speed => 0.0,speed_last5m => 0.0,speed_max => 0.0},
+                 emqx_rule_metrics:get_rule_metrics(Id)),
+    [?assertEqual(#{failed => 0, success => 0, taken => 0},
+                   emqx_rule_metrics:get_action_metrics(AId)) || AId <- [ActId0, ActId1, ActId2]],
+    emqtt:stop(Client),
+    emqx_rule_registry:remove_rule(Id),
+    ok = emqx_rule_registry:remove_action('crash_action'),
     ok.
 
 t_republish_action(_Config) ->
diff --git a/bin/emqx b/bin/emqx
index 01f2802cf..95840a1cb 100755
--- a/bin/emqx
+++ b/bin/emqx
@@ -525,7 +525,7 @@ esac
 
 if [ "$IS_BOOT_COMMAND" = 'no' ]; then
     # for non-boot commands, inspect vm.<time>.args for node name
-    # shellcheck disable=SC2012,SC2086
+    # shellcheck disable=SC2012
     LATEST_VM_ARGS_FILE="$(ls -t "$RUNNER_DATA_DIR"/configs/vm.*.args 2>/dev/null | head -1)"
     if [ -z "$LATEST_VM_ARGS_FILE" ]; then
         echoerr "There is no vm.*.args config file found in '$RUNNER_DATA_DIR/configs/'"
diff --git a/include/emqx_release.hrl b/include/emqx_release.hrl
index e932f7885..ca6b9ba01 100644
--- a/include/emqx_release.hrl
+++ b/include/emqx_release.hrl
@@ -29,7 +29,7 @@
 
 -ifndef(EMQX_ENTERPRISE).
 
--define(EMQX_RELEASE, {opensource, "4.4.10-alpha.1"}).
+-define(EMQX_RELEASE, {opensource, "4.4.10"}).
 
 -else.
 
diff --git a/lib-ce/emqx_dashboard/src/emqx_dashboard.app.src b/lib-ce/emqx_dashboard/src/emqx_dashboard.app.src
index 6ca32962f..d1860e208 100644
--- a/lib-ce/emqx_dashboard/src/emqx_dashboard.app.src
+++ b/lib-ce/emqx_dashboard/src/emqx_dashboard.app.src
@@ -1,6 +1,6 @@
 {application, emqx_dashboard,
  [{description, "EMQX Web Dashboard"},
-  {vsn, "4.4.9"}, % strict semver, bump manually!
+  {vsn, "4.4.10"}, % strict semver, bump manually!
   {modules, []},
   {registered, [emqx_dashboard_sup]},
   {applications, [kernel,stdlib,mnesia,minirest]},
diff --git a/rebar.config b/rebar.config
index c70c73216..00c725602 100644
--- a/rebar.config
+++ b/rebar.config
@@ -41,7 +41,7 @@
     [ {gpb, "4.11.2"} %% gpb only used to build, but not for release, pin it here to avoid fetching a wrong version due to rebar plugins scattered in all the deps
     , {redbug, "2.0.7"}
     , {ehttpc, {git, "https://github.com/emqx/ehttpc", {tag, "0.2.0"}}}
-    , {gun, {git, "https://github.com/emqx/gun", {tag, "1.3.7"}}}
+    , {gun, {git, "https://github.com/emqx/gun", {tag, "1.3.8"}}}
     , {eredis_cluster, {git, "https://github.com/emqx/eredis_cluster", {tag, "0.7.4"}}}
     , {gproc, {git, "https://github.com/uwiger/gproc", {tag, "0.9.0"}}}
     , {jiffy, {git, "https://github.com/emqx/jiffy", {tag, "1.0.5"}}}
diff --git a/scripts/check-apps-vsn.sh b/scripts/check-apps-vsn.sh
index 5b6e82d8a..3de9e7fe7 100755
--- a/scripts/check-apps-vsn.sh
+++ b/scripts/check-apps-vsn.sh
@@ -21,6 +21,24 @@ parse_semver() {
     echo "$1" | tr '.|-' ' '
 }
 
+exempt_bump() {
+  local app="$1"
+  local from="$2"
+  local to="$3"
+
+  case "$app,$from,$to" in
+    "lib-ee/emqx_conf,4.3.9,4.4.0")
+      true
+      ;;
+    "lib-ee/emqx_license,4.3.7,4.4.0")
+      true
+      ;;
+    *)
+      false
+      ;;
+  esac
+}
+
 check_apps() {
   while read -r app; do
     if [ "$app" != "emqx" ]; then
@@ -42,6 +60,7 @@ check_apps() {
     if [ "$old_app_version" = "$now_app_version" ]; then
         changed_lines="$(git diff "$latest_release"...HEAD --ignore-blank-lines -G "$no_comment_re" \
                              -- "$app_path/src" \
+                             -- "$app_path/include" \
                              -- ":(exclude)$app_path/src/*.appup.src" \
                              -- "$app_path/priv" \
                              -- "$app_path/c_src" | wc -l ) "
@@ -49,12 +68,12 @@ check_apps() {
             echo "$src_file needs a vsn bump (old=$old_app_version)"
             echo "changed: $changed_lines"
             bad_app_count=$(( bad_app_count + 1))
-        elif [ "$app" = 'emqx_dashboard' ]; then
+        elif [[ ${app_path} = *emqx_dashboard* ]]; then
             ## emqx_dashboard is ensured to be upgraded after all other plugins
             ## at the end of its appup instructions, there is the final instruction
             ## {apply, {emqx_plugins, load, []}
             ## since we don't know which plugins are stopped during the upgrade
-            ## for safety, we just force a dashboard version bump for each and every release
+            ## for safty, we just force a dashboard version bump for each and every release
             ## even if there is nothing changed in the app
             echo "$src_file needs a vsn bump to ensure plugins loaded after upgrade"
             bad_app_count=$(( bad_app_count + 1))
@@ -69,8 +88,12 @@ check_apps() {
             [ "$(( old_app_version_semver[2] + 1 ))" = "${now_app_version_semver[2]}" ]; then
             true
         else
+          if exempt_bump "$app" "$old_app_version" "$now_app_version"; then
+            true
+          else
             echo "$src_file: non-strict semver version bump from $old_app_version to $now_app_version"
             bad_app_count=$(( bad_app_count + 1))
+          fi
         fi
     fi
   done < <(./scripts/find-apps.sh)
diff --git a/scripts/get-dashboard.sh b/scripts/get-dashboard.sh
index dd9f0c6e2..65f9a0692 100755
--- a/scripts/get-dashboard.sh
+++ b/scripts/get-dashboard.sh
@@ -8,13 +8,13 @@ cd -P -- "$(dirname -- "${BASH_SOURCE[0]}")/.."
 PKG_VSN="${PKG_VSN:-$(./pkg-vsn.sh)}"
 case "${PKG_VSN}" in
     4.3*)
-        EMQX_CE_DASHBOARD_VERSION='v4.3.10'
-        EMQX_EE_DASHBOARD_VERSION='v4.3.24'
+        EMQX_CE_DASHBOARD_VERSION='v4.3.11'
+        EMQX_EE_DASHBOARD_VERSION='v4.3.26'
         ;;
     4.4*)
         # keep the above 4.3 untouched, otherwise conflicts!
-        EMQX_CE_DASHBOARD_VERSION='v4.4.5'
-        EMQX_EE_DASHBOARD_VERSION='v4.4.15'
+        EMQX_CE_DASHBOARD_VERSION='v4.4.6'
+        EMQX_EE_DASHBOARD_VERSION='v4.4.17'
         ;;
     *)
         echo "Unsupported version $PKG_VSN" >&2
diff --git a/scripts/rel/cut4x.sh b/scripts/rel/cut4x.sh
index 58131c757..df142b936 100755
--- a/scripts/rel/cut4x.sh
+++ b/scripts/rel/cut4x.sh
@@ -230,6 +230,16 @@ if [ "$HAS_RELUP_DB" = 'yes' ]; then
     ./scripts/relup-base-vsns.escript check-vsn-db "$PKG_VSN" "$RELUP_PATHS"
 fi
 
+## Run some additional checks (e.g. some for enterprise edition only)
+CHECKS_DIR="./scripts/rel/checks"
+if [ -d "${CHECKS_DIR}" ]; then
+    CHECKS="$(find "${CHECKS_DIR}" -name "*.sh" -print0 2>/dev/null | xargs -0)"
+    for c in $CHECKS; do
+        logmsg "Executing $c"
+        $c
+    done
+fi
+
 if [ "$DRYRUN" = 'yes' ]; then
     logmsg "Release tag is ready to be created with command: git tag $TAG"
 else
diff --git a/src/emqx.app.src b/src/emqx.app.src
index c27e2f5b5..e9f30de2f 100644
--- a/src/emqx.app.src
+++ b/src/emqx.app.src
@@ -6,7 +6,7 @@
   %% the emqx `release' version, which in turn is comprised of several
   %% apps, one of which is this.  See `emqx_release.hrl' for more
   %% info.
-  {vsn, "4.4.10"}, % strict semver, bump manually!
+  {vsn, "4.4.11"}, % strict semver, bump manually!
   {modules, []},
   {registered, []},
   {applications, [ kernel
diff --git a/src/emqx.appup.src b/src/emqx.appup.src
index 62b0b9042..cca029104 100644
--- a/src/emqx.appup.src
+++ b/src/emqx.appup.src
@@ -1,8 +1,12 @@
 %% -*- mode: erlang -*-
 %% Unless you know what you are doing, DO NOT edit manually!!
 {VSN,
-  [{"4.4.9",
-    [{load_module,emqx_misc,brutal_purge,soft_purge,[]},
+  [{"4.4.10",
+    [{load_module,emqx_cm,brutal_purge,soft_purge,[]},
+     {load_module,emqx_app,brutal_purge,soft_purge,[]}]},
+   {"4.4.9",
+    [{load_module,emqx_shared_sub,brutal_purge,soft_purge,[]},
+     {load_module,emqx_misc,brutal_purge,soft_purge,[]},
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {add_module,emqx_secret},
      {load_module,emqx_session,brutal_purge,soft_purge,[]},
@@ -270,8 +274,12 @@
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
      {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {<<".*">>,[]}],
-  [{"4.4.9",
-    [{load_module,emqx_misc,brutal_purge,soft_purge,[]},
+  [{"4.4.10",
+    [{load_module,emqx_cm,brutal_purge,soft_purge,[]},
+     {load_module,emqx_app,brutal_purge,soft_purge,[]}]},
+   {"4.4.9",
+    [{load_module,emqx_shared_sub,brutal_purge,soft_purge,[]},
+     {load_module,emqx_misc,brutal_purge,soft_purge,[]},
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_session,brutal_purge,soft_purge,[]},
      {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
diff --git a/src/emqx.erl b/src/emqx.erl
index ae78e5795..4f5f1e3f2 100644
--- a/src/emqx.erl
+++ b/src/emqx.erl
@@ -227,6 +227,7 @@ shutdown() ->
     shutdown(normal).
 
 shutdown(Reason) ->
+    ok = emqx_misc:maybe_mute_rpc_log(),
     ?LOG(critical, "emqx shutdown for ~s", [Reason]),
     on_shutdown(Reason),
     _ = emqx_plugins:unload(),
diff --git a/src/emqx_channel.erl b/src/emqx_channel.erl
index 51674263c..0d03c39cf 100644
--- a/src/emqx_channel.erl
+++ b/src/emqx_channel.erl
@@ -312,6 +312,7 @@ handle_in(?CONNECT_PACKET(ConnPkt) = Packet, Channel) ->
                    fun enrich_client/2,
                    fun set_log_meta/2,
                    fun check_banned/2,
+                   fun count_flapping_event/2,
                    fun auth_connect/2
                   ], ConnPkt, Channel#channel{conn_state = connecting}) of
         {ok, NConnPkt, NChannel = #channel{clientinfo = ClientInfo}} ->
@@ -1060,11 +1061,7 @@ handle_info({sock_closed, Reason}, Channel = #channel{conn_state = idle}) ->
 handle_info({sock_closed, Reason}, Channel = #channel{conn_state = connecting}) ->
     shutdown(Reason, Channel);
 
-handle_info({sock_closed, Reason}, Channel =
-            #channel{conn_state = connected,
-                     clientinfo = ClientInfo = #{zone := Zone}}) ->
-    emqx_zone:enable_flapping_detect(Zone)
-        andalso emqx_flapping:detect(ClientInfo),
+handle_info({sock_closed, Reason}, Channel = #channel{conn_state = connected}) ->
     Channel1 = ensure_disconnected(Reason, maybe_publish_will_msg(Channel)),
     case maybe_shutdown(Reason, Channel1) of
         {ok, Channel2} -> {ok, {event, disconnected}, Channel2};
@@ -1373,6 +1370,13 @@ auth_connect(#mqtt_packet_connect{password  = Password},
             {error, emqx_reason_codes:connack_error(Reason)}
     end.
 
+%%--------------------------------------------------------------------
+%% Flapping
+
+count_flapping_event(_ConnPkt, Channel = #channel{clientinfo = ClientInfo = #{zone := Zone}}) ->
+    _ = emqx_zone:enable_flapping_detect(Zone) andalso emqx_flapping:detect(ClientInfo),
+    {ok, Channel}.
+
 %%--------------------------------------------------------------------
 %% Enhanced Authentication
 
diff --git a/src/emqx_misc.erl b/src/emqx_misc.erl
index 07f50ddcc..d84e9189d 100644
--- a/src/emqx_misc.erl
+++ b/src/emqx_misc.erl
@@ -25,6 +25,7 @@
 
 -export([ merge_opts/2
         , maybe_apply/2
+        , maybe_mute_rpc_log/0
         , compose/1
         , compose/2
         , run_fold/3
@@ -446,6 +447,27 @@ do_parallel_map(Fun, List) ->
         PidList
     ).
 
+%% @doc Call this function to avoid logs printed to RPC caller node.
+-spec maybe_mute_rpc_log() -> ok.
+maybe_mute_rpc_log() ->
+    GlNode = node(group_leader()),
+    maybe_mute_rpc_log(GlNode).
+
+maybe_mute_rpc_log(Node) when Node =:= node() ->
+    %% do nothing, this is a local call
+    ok;
+maybe_mute_rpc_log(Node) ->
+    case atom_to_list(Node) of
+        "remsh" ++ _ ->
+            %% this is either an upgrade script or nodetool
+            %% do nothing, the log may go to the 'emqx' command line console
+            ok;
+        _ ->
+            %% otherwise set group leader to local node
+            _ = group_leader(whereis(init), self()),
+            ok
+    end.
+
 -ifdef(TEST).
 -include_lib("eunit/include/eunit.hrl").
 
diff --git a/src/emqx_session.erl b/src/emqx_session.erl
index 217e26bb0..7765f7d7a 100644
--- a/src/emqx_session.erl
+++ b/src/emqx_session.erl
@@ -683,26 +683,35 @@ run_terminate_hooks(ClientInfo, takeovered, Session) ->
 run_terminate_hooks(ClientInfo, Reason, Session) ->
     run_hook('session.terminated', [ClientInfo, Reason, info(Session)]).
 
-redispatch_shared_messages(#session{inflight = Inflight}) ->
-    InflightList = emqx_inflight:to_list(Inflight),
-    lists:foreach(fun
-        %% Only QoS1 messages get redispatched, because QoS2 messages
-        %% must be sent to the same client, once they're in flight
-        ({_, {#message{qos = ?QOS_2} = Msg, _}}) ->
-          ?LOG(warning, "Not redispatching qos2 msg: ~s", [emqx_message:format(Msg)]);
-        ({_, {#message{topic = Topic, qos = ?QOS_1} = Msg, _}}) ->
-          case emqx_shared_sub:get_group(Msg) of
-              {ok, Group} ->
-                  %% Note that dispatch is called with self() in failed subs
-                  %% This is done to avoid dispatching back to caller
-                  Delivery = #delivery{sender = self(), message = Msg},
-                  emqx_shared_sub:dispatch_to_non_self(Group, Topic, Delivery);
-              _ ->
-                  false
-          end;
-        (_) ->
-          ok
-    end, InflightList).
+redispatch_shared_messages(#session{inflight = Inflight, mqueue = Q}) ->
+    AllInflights = emqx_inflight:to_list(sort_fun(), Inflight),
+    F = fun({_, {Msg, _Ts}}) ->
+            case Msg of
+                #message{qos = ?QOS_1} ->
+                    %% For QoS 2, here is what the spec says:
+                    %% If the Client's Session terminates before the Client reconnects,
+                    %% the Server MUST NOT send the Application Message to any other
+                    %% subscribed Client [MQTT-4.8.2-5].
+                    {true, Msg};
+                _ ->
+                    %% QoS 2, after pubrec is received
+                    %% the inflight record is updated to an atom
+                    false
+            end
+        end,
+    InflightList = lists:filtermap(F, AllInflights),
+    MqList = mqueue_to_list(Q, []),
+    emqx_shared_sub:redispatch(InflightList ++ MqList).
+
+%% convert mqueue to a list
+%% the messages at the head of the list is to be dispatched before the tail
+mqueue_to_list(Q, Acc) ->
+    case emqx_mqueue:out(Q) of
+        {empty, _Q} ->
+            lists:reverse(Acc);
+        {{value, Msg}, Q1} ->
+            mqueue_to_list(Q1, [Msg | Acc])
+    end.
 
 -compile({inline, [run_hook/2]}).
 run_hook(Name, Args) ->
diff --git a/src/emqx_shared_sub.erl b/src/emqx_shared_sub.erl
index cc57e001f..9c051c62a 100644
--- a/src/emqx_shared_sub.erl
+++ b/src/emqx_shared_sub.erl
@@ -39,7 +39,7 @@
         ]).
 
 -export([ dispatch/3
-        , dispatch_to_non_self/3
+        , redispatch/1
         ]).
 
 -export([ maybe_ack/1
@@ -47,7 +47,6 @@
         , nack_no_connection/1
         , is_ack_required/1
         , is_retry_dispatch/1
-        , get_group/1
         ]).
 
 %% for testing
@@ -84,6 +83,9 @@
 -define(ACK, shared_sub_ack).
 -define(NACK(Reason), {shared_sub_nack, Reason}).
 -define(NO_ACK, no_ack).
+-define(REDISPATCH_TO(GROUP, TOPIC), {GROUP, TOPIC}).
+
+-type redispatch_to() :: ?REDISPATCH_TO(emqx_topic:group(), emqx_topic:topic()).
 
 -record(state, {pmon}).
 
@@ -134,11 +136,12 @@ dispatch(Group, Topic, Delivery) ->
     Strategy = strategy(Group),
     dispatch(Strategy, Group, Topic, Delivery, _FailedSubs = #{}).
 
-dispatch(Strategy, Group, Topic, Delivery = #delivery{message = Msg}, FailedSubs) ->
-    #message{from = ClientId, topic = SourceTopic} = Msg,
+dispatch(Strategy, Group, Topic, Delivery = #delivery{message = Msg0}, FailedSubs) ->
+    #message{from = ClientId, topic = SourceTopic} = Msg0,
     case pick(Strategy, ClientId, SourceTopic, Group, Topic, FailedSubs) of
         false -> {error, no_subscribers};
         {Type, SubPid} ->
+            Msg = with_redispatch_to(Msg0, Group, Topic),
             case do_dispatch(SubPid, Group, Topic, Msg, Type) of
                 ok -> {ok, 1};
                 {error, Reason} ->
@@ -162,7 +165,7 @@ ack_enabled() ->
     emqx:get_env(shared_dispatch_ack_enabled, false).
 
 do_dispatch(SubPid, _Group, Topic, Msg, _Type) when SubPid =:= self() ->
-    %% Deadlock otherwise
+    %% dispatch without ack, deadlock otherwise
     send(SubPid, Topic, {deliver, Topic, Msg});
 %% return either 'ok' (when everything is fine) or 'error'
 do_dispatch(SubPid, _Group, Topic, #message{qos = ?QOS_0} = Msg, _Type) ->
@@ -176,6 +179,10 @@ do_dispatch(SubPid, Group, Topic, Msg, Type) ->
             send(SubPid, Topic, {deliver, Topic, Msg})
     end.
 
+with_redispatch_to(#message{qos = ?QOS_0} = Msg, _Group, _Topic) -> Msg;
+with_redispatch_to(Msg, Group, Topic) ->
+    emqx_message:set_headers(#{redispatch_to => ?REDISPATCH_TO(Group, Topic)}, Msg).
+
 dispatch_with_ack(SubPid, Group, Topic, Msg, Type) ->
     %% For QoS 1/2 message, expect an ack
     Ref = erlang:monitor(process, SubPid),
@@ -228,13 +235,22 @@ without_group_ack(Msg) ->
 get_group_ack(Msg) ->
     emqx_message:get_header(shared_dispatch_ack, Msg, ?NO_ACK).
 
--spec(get_group(emqx_types:message()) -> {ok, any()} | error).
-get_group(Msg) ->
-    case get_group_ack(Msg) of
-        {_Sender, {_Type, Group, _Ref}} -> {ok, Group};
-        _ -> error
+%% @hidden Redispatch is neede only for the messages with redispatch_to header added.
+is_redispatch_needed(#message{} = Msg) ->
+    case get_redispatch_to(Msg) of
+        ?REDISPATCH_TO(_, _) ->
+            true;
+        _ ->
+            false
     end.
 
+%% @hidden Return the `redispatch_to` group-topic in the message header.
+%% `false` is returned if the message is not a shared dispatch.
+%% or when it's a QoS 0 message.
+-spec(get_redispatch_to(emqx_types:message()) -> redispatch_to() | false).
+get_redispatch_to(Msg) ->
+    emqx_message:get_header(redispatch_to, Msg, false).
+
 -spec(is_ack_required(emqx_types:message()) -> boolean()).
 is_ack_required(Msg) -> ?NO_ACK =/= get_group_ack(Msg).
 
@@ -245,6 +261,26 @@ is_retry_dispatch(Msg) ->
         _ -> false
     end.
 
+%% @doc Redispatch shared deliveries to other members in the group.
+redispatch(Messages0) ->
+    Messages = lists:filter(fun is_redispatch_needed/1, Messages0),
+    case length(Messages) of
+        L when L > 0 ->
+            ?LOG(info, "Redispatching ~p shared subscription message(s)", [L]),
+            lists:foreach(fun redispatch_shared_message/1, Messages);
+        _ ->
+            ok
+    end.
+
+redispatch_shared_message(#message{} = Msg) ->
+    %% As long as it's still a #message{} record in inflight,
+    %% we should try to re-dispatch
+    ?REDISPATCH_TO(Group, Topic) = get_redispatch_to(Msg),
+    %% Note that dispatch is called with self() in failed subs
+    %% This is done to avoid dispatching back to caller
+    Delivery = #delivery{sender = self(), message = Msg},
+    dispatch_to_non_self(Group, Topic, Delivery).
+
 %% @doc Negative ack dropped message due to inflight window or message queue being full.
 -spec(maybe_nack_dropped(emqx_types:message()) -> store | drop).
 maybe_nack_dropped(Msg) ->
@@ -301,7 +337,8 @@ fetch_sender_ref({Sender, Ref}) -> {Sender, Ref}.
 
 pick(sticky, ClientId, SourceTopic, Group, Topic, FailedSubs) ->
     Sub0 = erlang:get({shared_sub_sticky, Group, Topic}),
-    case is_active_sub(Sub0, FailedSubs) of
+    All = subscribers(Group, Topic),
+    case is_active_sub(Sub0, FailedSubs, All) of
         true ->
             %% the old subscriber is still alive
             %% keep using it for sticky strategy
@@ -419,6 +456,7 @@ handle_cast(Msg, State) ->
 
 handle_info({mnesia_table_event, {write, NewRecord, _}}, State = #state{pmon = PMon}) ->
     #emqx_shared_subscription{subpid = SubPid} = NewRecord,
+    ok = maybe_insert_alive_tab(SubPid),
     {noreply, update_stats(State#state{pmon = emqx_pmon:monitor(SubPid, PMon)})};
 
 %% The subscriber may have subscribed multiple topics, so we need to keep monitoring the PID until
@@ -471,8 +509,10 @@ update_stats(State) ->
     State.
 
 %% Return 'true' if the subscriber process is alive AND not in the failed list
-is_active_sub(Pid, FailedSubs) ->
-    not maps:is_key(Pid, FailedSubs) andalso is_alive_sub(Pid).
+is_active_sub(Pid, FailedSubs, All) ->
+    lists:member(Pid, All) andalso
+        (not maps:is_key(Pid, FailedSubs)) andalso
+        is_alive_sub(Pid).
 
 %% erlang:is_process_alive/1 does not work with remote pid.
 is_alive_sub(Pid) when ?IS_LOCAL_PID(Pid) ->
diff --git a/test/emqx_channel_SUITE.erl b/test/emqx_channel_SUITE.erl
index 06e5e4eaa..e887d35f4 100644
--- a/test/emqx_channel_SUITE.erl
+++ b/test/emqx_channel_SUITE.erl
@@ -35,11 +35,7 @@ init_per_suite(Config) ->
     ok = meck:new(emqx_cm, [passthrough, no_history, no_link]),
     ok = meck:expect(emqx_cm, mark_channel_connected, fun(_) -> ok end),
     ok = meck:expect(emqx_cm, mark_channel_disconnected, fun(_) -> ok end),
-    %% Access Control Meck
-    ok = meck:new(emqx_access_control, [passthrough, no_history, no_link]),
-    ok = meck:expect(emqx_access_control, authenticate,
-                     fun(_) -> {ok, #{auth_result => success}} end),
-    ok = meck:expect(emqx_access_control, check_acl, fun(_, _, _) -> allow end),
+
     %% Broker Meck
     ok = meck:new(emqx_broker, [passthrough, no_history, no_link]),
     %% Hooks Meck
@@ -55,8 +51,7 @@ init_per_suite(Config) ->
     Config.
 
 end_per_suite(_Config) ->
-    meck:unload([emqx_access_control,
-                 emqx_metrics,
+    meck:unload([emqx_metrics,
                  emqx_session,
                  emqx_broker,
                  emqx_hooks,
@@ -65,10 +60,16 @@ end_per_suite(_Config) ->
 
 init_per_testcase(_TestCase, Config) ->
     meck:new(emqx_zone, [passthrough, no_history, no_link]),
+    %% Access Control Meck
+    ok = meck:new(emqx_access_control, [passthrough, no_history, no_link]),
+    ok = meck:expect(emqx_access_control, authenticate,
+                     fun(_) -> {ok, #{auth_result => success}} end),
+    ok = meck:expect(emqx_access_control, check_acl, fun(_, _, _) -> allow end),
     Config.
 
 end_per_testcase(_TestCase, Config) ->
     meck:unload([emqx_zone]),
+    meck:unload([emqx_access_control]),
     Config.
 
 %%--------------------------------------------------------------------
@@ -855,6 +856,30 @@ t_ws_cookie_init(_) ->
     Channel = emqx_channel:init(ConnInfo, [{zone, zone}]),
     ?assertMatch(#{ws_cookie := WsCookie}, emqx_channel:info(clientinfo, Channel)).
 
+%%--------------------------------------------------------------------
+%% Test cases for other mechnisms
+%%--------------------------------------------------------------------
+
+t_flapping_detect(_) ->
+    Parent = self(),
+    ok = meck:expect(emqx_cm, open_session,
+                     fun(true, _ClientInfo, _ConnInfo) ->
+                             {ok, #{session => session(), present => false}}
+                     end),
+    ok = meck:expect(emqx_access_control, authenticate, fun(_) -> {error, not_authorized} end),
+    ok = meck:new(emqx_flapping, [passthrough, no_history, no_link]),
+    ok = meck:expect(emqx_flapping, detect, fun(_) -> Parent ! flapping_detect end),
+    ok = meck:expect(emqx_zone, enable_flapping_detect, fun(_) -> true end),
+    IdleChannel = channel(#{conn_state => idle}),
+    {shutdown, not_authorized, _ConnAck, _Channel} =
+        emqx_channel:handle_in(?CONNECT_PACKET(connpkt()), IdleChannel),
+    receive
+        flapping_detect -> ok
+    after 2000 ->
+              ?assert(false, "Flapping detect should be exected in connecting progress")
+    end,
+    meck:unload([emqx_flapping]).
+
 %%--------------------------------------------------------------------
 %% Helper functions
 %%--------------------------------------------------------------------
diff --git a/test/emqx_flapping_SUITE.erl b/test/emqx_flapping_SUITE.erl
index eadd89192..8074a8607 100644
--- a/test/emqx_flapping_SUITE.erl
+++ b/test/emqx_flapping_SUITE.erl
@@ -72,4 +72,4 @@ t_expired_detecting(_) ->
                                     (_) -> false end, ets:tab2list(emqx_flapping))),
     timer:sleep(200),
     ?assertEqual(true, lists:all(fun({flapping, <<"clientid">>, _, _, _}) -> false;
-                                    (_) -> true end, ets:tab2list(emqx_flapping))).
\ No newline at end of file
+                                    (_) -> true end, ets:tab2list(emqx_flapping))).
diff --git a/test/emqx_node_helpers.erl b/test/emqx_node_helpers.erl
index ad530b3d7..af7093dd7 100644
--- a/test/emqx_node_helpers.erl
+++ b/test/emqx_node_helpers.erl
@@ -40,7 +40,9 @@ start_slave(Name, Opts) ->
         {ok, _} ->
             ok;
         {error, started_not_connected, _} ->
-            ok
+            ok;
+        Other ->
+            throw(Other)
     end,
     pong = net_adm:ping(Node),
     setup_node(Node, Opts),
@@ -92,7 +94,11 @@ setup_node(Node, #{} = Opts) ->
         end,
     EnvHandler = maps:get(env_handler, Opts, DefaultEnvHandler),
 
-    [ok = rpc:call(Node, application, load, [App]) || App <- [gen_rpc, emqx]],
+    %% apps need to be loaded before starting for ekka to find and create mnesia tables
+    LoadApps = lists:usort([gen_rcp, emqx] ++ ?SLAVE_START_APPS),
+    lists:foreach(fun(App) ->
+                          rpc:call(Node, application, load, [App])
+                  end, LoadApps),
     ok = rpc:call(Node, emqx_ct_helpers, start_apps, [StartApps, EnvHandler]),
 
     case maps:get(no_join, Opts, false) of
diff --git a/test/emqx_shared_sub_SUITE.erl b/test/emqx_shared_sub_SUITE.erl
index 9ffce523d..2c4ecf265 100644
--- a/test/emqx_shared_sub_SUITE.erl
+++ b/test/emqx_shared_sub_SUITE.erl
@@ -25,13 +25,24 @@
 
 -define(SUITE, ?MODULE).
 
--define(wait(For, Timeout),
-        emqx_ct_helpers:wait_for(
-          ?FUNCTION_NAME, ?LINE, fun() -> For end, Timeout)).
-
 -define(ack, shared_sub_ack).
 -define(no_ack, no_ack).
 
+-define(WAIT(TIMEOUT, PATTERN, Res),
+        (fun() ->
+            receive
+                PATTERN ->
+                    Res;
+                Other ->
+                    ct:fail(#{expected => ??PATTERN,
+                              got => Other
+                             })
+            after
+                TIMEOUT ->
+                    ct:fail({timeout, ??PATTERN})
+            end
+        end)()).
+
 all() -> emqx_ct:all(?SUITE).
 
 init_per_suite(Config) ->
@@ -151,40 +162,7 @@ t_no_connection_nack(Config) when is_list(Config) ->
     SendF(1),
     ct:sleep(200),
     %% This is the connection which was picked by broker to dispatch (sticky) for 1st message
-
     ?assertMatch([#{packet_id := 1}], recv_msgs(1)),
-    %% Now kill the connection, expect all following messages to be delivered to the other
-    %% subscriber.
-    %emqx_mock_client:stop(ConnPid),
-    %% sleep then make synced calls to session processes to ensure that
-    %% the connection pid's 'EXIT' message is propagated to the session process
-    %% also to be sure sessions are still alive
-    %   timer:sleep(2),
-    %   _ = emqx_session:info(SPid1),
-    %   _ = emqx_session:info(SPid2),
-    %   %% Now we know what is the other still alive connection
-    %   [TheOtherConnPid] = [SubConnPid1, SubConnPid2] -- [ConnPid],
-    %   %% Send some more messages
-    %   PacketIdList = lists:seq(2, 10),
-    %   lists:foreach(fun(Id) ->
-    %                         SendF(Id),
-    %                         ?wait(Received(Id, TheOtherConnPid), 1000)
-    %                 end, PacketIdList),
-    %   %% Now close the 2nd (last connection)
-    %   emqx_mock_client:stop(TheOtherConnPid),
-    %   timer:sleep(2),
-    %   %% both sessions should have conn_pid = undefined
-    %   ?assertEqual({conn_pid, undefined}, lists:keyfind(conn_pid, 1, emqx_session:info(SPid1))),
-    %   ?assertEqual({conn_pid, undefined}, lists:keyfind(conn_pid, 1, emqx_session:info(SPid2))),
-    %   %% send more messages, but all should be queued in session state
-    %   lists:foreach(fun(Id) -> SendF(Id) end, PacketIdList),
-    %   {_, L1} = lists:keyfind(mqueue_len, 1, emqx_session:info(SPid1)),
-    %   {_, L2} = lists:keyfind(mqueue_len, 1, emqx_session:info(SPid2)),
-    %   ?assertEqual(length(PacketIdList), L1 + L2),
-    %   %% clean up
-    %   emqx_mock_client:close_session(PubConnPid),
-    %   emqx_sm:close_session(SPid1),
-    %   emqx_sm:close_session(SPid2),
     ok.
 
 t_random(Config) when is_list(Config) ->
@@ -443,8 +421,14 @@ t_local_fallback(Config) when is_list(Config) ->
 
 %% This one tests that broker tries to select another shared subscriber
 %% If the first one doesn't return an ACK
-t_redispatch(Config) when is_list(Config) ->
-    ok = ensure_config(sticky, true),
+t_redispatch_with_ack(Config) when is_list(Config) ->
+    test_redispatch(Config, true).
+
+t_redispatch_no_ack(Config) when is_list(Config) ->
+    test_redispatch(Config, false).
+
+test_redispatch(_Config, AckEnabled) ->
+    ok = ensure_config(sticky, AckEnabled),
     application:set_env(emqx, shared_dispatch_ack_enabled, true),
 
     Group = <<"group1">>,
@@ -474,15 +458,59 @@ t_redispatch(Config) when is_list(Config) ->
     emqtt:stop(UsedSubPid2),
     ok.
 
+t_redispatch_wildcard_with_ack(Config) when is_list(Config)->
+    redispatch_wildcard(Config, true).
+
+t_redispatch_wildcard_no_ack(Config) when is_list(Config) ->
+    redispatch_wildcard(Config, false).
+
+%% This one tests that broker tries to redispatch to another member in the group
+%% if the first one disconnected before acking (auto_ack set to false)
+redispatch_wildcard(_Config, AckEnabled) ->
+    ok = ensure_config(sticky, AckEnabled),
+
+    Group = <<"group1">>,
+
+    Topic = <<"foo/bar/1">>,
+    ClientId1 = <<"ClientId1">>,
+    ClientId2 = <<"ClientId2">>,
+    {ok, ConnPid1} = emqtt:start_link([{clientid, ClientId1}, {auto_ack, false}]),
+    {ok, ConnPid2} = emqtt:start_link([{clientid, ClientId2}, {auto_ack, false}]),
+    {ok, _} = emqtt:connect(ConnPid1),
+    {ok, _} = emqtt:connect(ConnPid2),
+
+    emqtt:subscribe(ConnPid1, {<<"$share/", Group/binary, "/foo/bar/#">>, 1}),
+    emqtt:subscribe(ConnPid2, {<<"$share/", Group/binary, "/foo/bar/#">>, 1}),
+
+    Message = emqx_message:make(ClientId1, 1, Topic, <<"hello1">>),
+
+    emqx:publish(Message),
+
+    {true, UsedSubPid1} = last_message(<<"hello1">>, [ConnPid1, ConnPid2]),
+    ok = emqtt:stop(UsedSubPid1),
+
+    Res = last_message(<<"hello1">>, [ConnPid1, ConnPid2], 6000),
+    ?assertMatch({true, Pid} when Pid =/= UsedSubPid1, Res),
+
+    {true, UsedSubPid2} = Res,
+    emqtt:stop(UsedSubPid2),
+    ok.
+
+t_dispatch_when_inflights_are_full({init, Config}) ->
+    %% make sure broker does not push more than one inflight
+    meck:new(emqx_zone, [passthrough, no_history]),
+    meck:expect(emqx_zone, max_inflight, fun(_Zone) -> 1 end),
+    Config;
+t_dispatch_when_inflights_are_full({'end', _Config}) ->
+    meck:unload(emqx_zone);
 t_dispatch_when_inflights_are_full(Config) when is_list(Config) ->
-    ok = ensure_config(round_robin, true),
+    ok = ensure_config(round_robin, _AckEnabled = true),
     Topic = <<"foo/bar">>,
     ClientId1 = <<"ClientId1">>,
     ClientId2 = <<"ClientId2">>,
 
-    %% Note that max_inflight is 1
-    {ok, ConnPid1} = emqtt:start_link([{clientid, ClientId1}, {max_inflight, 1}]),
-    {ok, ConnPid2} = emqtt:start_link([{clientid, ClientId2}, {max_inflight, 1}]),
+    {ok, ConnPid1} = emqtt:start_link([{clientid, ClientId1}]),
+    {ok, ConnPid2} = emqtt:start_link([{clientid, ClientId2}]),
     {ok, _} = emqtt:connect(ConnPid1),
     {ok, _} = emqtt:connect(ConnPid2),
 
@@ -505,8 +533,7 @@ t_dispatch_when_inflights_are_full(Config) when is_list(Config) ->
     ?assertMatch([{_, _, {ok, 1}}], emqx:publish(Message2)),
 
     %% Now kill any client
-    erlang:exit(ConnPid1, normal),
-    ct:sleep(100),
+    ok = kill_process(ConnPid1),
 
     %% And try to send the message
     ?assertMatch([{_, _, {ok, 1}}], emqx:publish(Message3)),
@@ -521,10 +548,137 @@ t_dispatch_when_inflights_are_full(Config) when is_list(Config) ->
     emqtt:stop(ConnPid2),
     ok.
 
+%% No ack, QoS 2 subscriptions,
+%% client1 receives one message, send pubrec, then suspend
+%% client2 acts normal (auto_ack=true)
+%% Expected behaviour:
+%% the messages sent to client1's inflight and mq are re-dispatched after client1 is down
+t_dispatch_qos2({init, Config}) when is_list(Config) ->
+    meck:new(emqx_zone, [passthrough, no_history]),
+    meck:expect(emqx_zone, max_inflight, fun(_Zone) -> 1 end),
+    Config;
+t_dispatch_qos2({'end', Config}) when is_list(Config) ->
+    meck:unload(emqx_zone);
+t_dispatch_qos2(Config) when is_list(Config) ->
+    ok = ensure_config(round_robin, _AckEnabled = false),
+    Topic = <<"foo/bar/1">>,
+    ClientId1 = <<"ClientId1">>,
+    ClientId2 = <<"ClientId2">>,
+
+    {ok, ConnPid1} = emqtt:start_link([{clientid, ClientId1}, {auto_ack, false}]),
+    {ok, ConnPid2} = emqtt:start_link([{clientid, ClientId2}, {auto_ack, true}]),
+    {ok, _} = emqtt:connect(ConnPid1),
+    {ok, _} = emqtt:connect(ConnPid2),
+
+    emqtt:subscribe(ConnPid1, {<<"$share/group/foo/bar/#">>, 2}),
+    emqtt:subscribe(ConnPid2, {<<"$share/group/foo/bar/#">>, 2}),
+
+    Message1 = emqx_message:make(ClientId1, 2, Topic, <<"hello1">>),
+    Message2 = emqx_message:make(ClientId1, 2, Topic, <<"hello2">>),
+    Message3 = emqx_message:make(ClientId1, 2, Topic, <<"hello3">>),
+    Message4 = emqx_message:make(ClientId1, 2, Topic, <<"hello4">>),
+    ct:sleep(100),
+
+    ok = sys:suspend(ConnPid1),
+
+    %% One message is inflight
+    ?assertMatch([{_, _, {ok, 1}}], emqx:publish(Message1)),
+    ?assertMatch([{_, _, {ok, 1}}], emqx:publish(Message2)),
+    ?assertMatch([{_, _, {ok, 1}}], emqx:publish(Message3)),
+    ?assertMatch([{_, _, {ok, 1}}], emqx:publish(Message4)),
+
+    MsgRec1 = ?WAIT(2000, {publish, #{client_pid := ConnPid2, payload := P1}}, P1),
+    MsgRec2 = ?WAIT(2000, {publish, #{client_pid := ConnPid2, payload := P2}}, P2),
+    %% assert hello2 > hello1 or hello4 > hello3
+    ?assert(MsgRec2 > MsgRec1),
+
+    sys:resume(ConnPid1),
+    %% emqtt subscriber automatically sends PUBREC, but since auto_ack is set to false
+    %% so it will never send PUBCOMP, hence EMQX should not attempt to send
+    %% the 4th message yet since max_inflight is 1.
+    MsgRec3 = ?WAIT(2000, {publish, #{client_pid := ConnPid1, payload := P3}}, P3),
+    ct:sleep(100),
+    %% no message expected
+    ?assertEqual([], collect_msgs(0)),
+    %% now kill client 1
+    kill_process(ConnPid1),
+    %% client 2 should receive the message
+    MsgRec4 = ?WAIT(2000, {publish, #{client_pid := ConnPid2, payload := P4}}, P4),
+    %% assert hello2 > hello1 or hello4 > hello3
+    ?assert(MsgRec4 > MsgRec3),
+    emqtt:stop(ConnPid2),
+    ok.
+
+t_dispatch_qos0({init, Config}) when is_list(Config) ->
+    Config;
+t_dispatch_qos0({'end', Config}) when is_list(Config) ->
+    ok;
+t_dispatch_qos0(Config) when is_list(Config) ->
+    ok = ensure_config(round_robin, _AckEnabled = false),
+    Topic = <<"foo/bar/1">>,
+    ClientId1 = <<"ClientId1">>,
+    ClientId2 = <<"ClientId2">>,
+
+    {ok, ConnPid1} = emqtt:start_link([{clientid, ClientId1}, {auto_ack, false}]),
+    {ok, ConnPid2} = emqtt:start_link([{clientid, ClientId2}, {auto_ack, true}]),
+    {ok, _} = emqtt:connect(ConnPid1),
+    {ok, _} = emqtt:connect(ConnPid2),
+
+    %% subscribe with QoS 0
+    emqtt:subscribe(ConnPid1, {<<"$share/group/foo/bar/#">>, 0}),
+    emqtt:subscribe(ConnPid2, {<<"$share/group/foo/bar/#">>, 0}),
+
+    %% publish with QoS 2, but should be downgraded to 0 as the subscribers
+    %% subscribe with QoS 0
+    Message1 = emqx_message:make(ClientId1, 2, Topic, <<"hello1">>),
+    Message2 = emqx_message:make(ClientId1, 2, Topic, <<"hello2">>),
+    Message3 = emqx_message:make(ClientId1, 2, Topic, <<"hello3">>),
+    Message4 = emqx_message:make(ClientId1, 2, Topic, <<"hello4">>),
+    ct:sleep(100),
+
+    ok = sys:suspend(ConnPid1),
+
+    ?assertMatch([_], emqx:publish(Message1)),
+    ?assertMatch([_], emqx:publish(Message2)),
+    ?assertMatch([_], emqx:publish(Message3)),
+    ?assertMatch([_], emqx:publish(Message4)),
+
+    MsgRec1 = ?WAIT(2000, {publish, #{client_pid := ConnPid2, payload := P1}}, P1),
+    MsgRec2 = ?WAIT(2000, {publish, #{client_pid := ConnPid2, payload := P2}}, P2),
+    %% assert hello2 > hello1 or hello4 > hello3
+    ?assert(MsgRec2 > MsgRec1),
+
+    kill_process(ConnPid1),
+    %% expect no redispatch
+    ?assertEqual([], collect_msgs(timer:seconds(2))),
+    emqtt:stop(ConnPid2),
+    ok.
+
 %%--------------------------------------------------------------------
 %% help functions
 %%--------------------------------------------------------------------
 
+kill_process(Pid) ->
+    _ = unlink(Pid),
+    _ = monitor(process, Pid),
+    erlang:exit(Pid, kill),
+    receive
+        {'DOWN', _, process, Pid, _} ->
+            ok
+    end.
+
+collect_msgs(Timeout) ->
+    collect_msgs([], Timeout).
+
+collect_msgs(Acc, Timeout) ->
+    receive
+        Msg ->
+            collect_msgs([Msg | Acc], Timeout)
+    after
+        Timeout ->
+            lists:reverse(Acc)
+    end.
+
 ensure_config(Strategy) ->
     ensure_config(Strategy, _AckEnabled = true).