diff --git a/apps/emqx/src/emqx_trie.erl b/apps/emqx/src/emqx_trie.erl
index 05514f184..628b3336d 100644
--- a/apps/emqx/src/emqx_trie.erl
+++ b/apps/emqx/src/emqx_trie.erl
@@ -270,6 +270,9 @@ match_compact([Word | Words], Prefix, IsWildcard, Acc0) ->
 is_compact() ->
     emqx_config:get([broker, perf, trie_compaction], true).
 
+set_compact(Bool) ->
+    emqx_config:put([broker, perf, trie_compaction], Bool).
+
 -ifdef(TEST).
 -include_lib("eunit/include/eunit.hrl").
 
@@ -325,9 +328,6 @@ do_compact_test() ->
                  do_compact(words(<<"a/+/+/+/+/b">>))),
     ok.
 
-set_compact(Bool) ->
-    emqx_config:put([broker, perf, trie_compaction], Bool).
-
 clear_tables() -> ekka_mnesia:clear_table(?TRIE).
 
 -endif. % TEST
diff --git a/apps/emqx/test/emqx_cm_registry_SUITE.erl b/apps/emqx/test/emqx_cm_registry_SUITE.erl
index 097bfc7b4..35f748477 100644
--- a/apps/emqx/test/emqx_cm_registry_SUITE.erl
+++ b/apps/emqx/test/emqx_cm_registry_SUITE.erl
@@ -42,26 +42,26 @@ end_per_testcase(_TestCase, Config) ->
     Config.
 
 t_is_enabled(_) ->
-    application:set_env(emqx, enable_session_registry, false),
+    emqx_config:put([broker, enable_session_registry], false),
     ?assertEqual(false, emqx_cm_registry:is_enabled()),
-    application:set_env(emqx, enable_session_registry, true),
+    emqx_config:put([broker, enable_session_registry], true),
     ?assertEqual(true, emqx_cm_registry:is_enabled()).
 
 t_register_unregister_channel(_) ->
     ClientId = <<"clientid">>,
-    application:set_env(emqx, enable_session_registry, false),
+    emqx_config:put([broker, enable_session_registry], false),
     emqx_cm_registry:register_channel(ClientId),
     ?assertEqual([], emqx_cm_registry:lookup_channels(ClientId)),
 
-    application:set_env(emqx, enable_session_registry, true),
+    emqx_config:put([broker, enable_session_registry], true),
     emqx_cm_registry:register_channel(ClientId),
     ?assertEqual([self()], emqx_cm_registry:lookup_channels(ClientId)),
 
-    application:set_env(emqx, enable_session_registry, false),
+    emqx_config:put([broker, enable_session_registry], false),
     emqx_cm_registry:unregister_channel(ClientId),
     ?assertEqual([self()], emqx_cm_registry:lookup_channels(ClientId)),
 
-    application:set_env(emqx, enable_session_registry, true),
+    emqx_config:put([broker, enable_session_registry], true),
     emqx_cm_registry:unregister_channel(ClientId),
     ?assertEqual([], emqx_cm_registry:lookup_channels(ClientId)).
 
diff --git a/apps/emqx/test/emqx_global_gc_SUITE.erl b/apps/emqx/test/emqx_global_gc_SUITE.erl
index 92d6a5251..643e5dd0d 100644
--- a/apps/emqx/test/emqx_global_gc_SUITE.erl
+++ b/apps/emqx/test/emqx_global_gc_SUITE.erl
@@ -24,7 +24,7 @@
 all() -> emqx_ct:all(?MODULE).
 
 t_run_gc(_) ->
-    ok = application:set_env(emqx, global_gc_interval, 1),
+    ok = emqx_config:put([node, global_gc_interval], 1),
     {ok, _} = emqx_global_gc:start_link(),
     ok = timer:sleep(1500),
     {ok, MilliSecs} = emqx_global_gc:run(),
diff --git a/apps/emqx/test/emqx_mqtt_protocol_v5_SUITE.erl b/apps/emqx/test/emqx_mqtt_protocol_v5_SUITE.erl
index 8de571ba8..ff04055e6 100644
--- a/apps/emqx/test/emqx_mqtt_protocol_v5_SUITE.erl
+++ b/apps/emqx/test/emqx_mqtt_protocol_v5_SUITE.erl
@@ -786,7 +786,7 @@ t_shared_subscriptions_client_terminates_when_qos_eq_2('end', _Config) ->
 t_shared_subscriptions_client_terminates_when_qos_eq_2(Config) ->
     ConnFun = ?config(conn_fun, Config),
     process_flag(trap_exit, true),
-    application:set_env(emqx, shared_dispatch_ack_enabled, true),
+    emqx_config:put([broker, shared_dispatch_ack_enabled], true),
 
     Topic = nth(1, ?TOPICS),
     SharedTopic = list_to_binary("$share/sharename/" ++ binary_to_list(<<"TopicA">>)),
diff --git a/apps/emqx/test/emqx_plugins_SUITE.erl b/apps/emqx/test/emqx_plugins_SUITE.erl
index a7dd91602..6d8978563 100644
--- a/apps/emqx/test/emqx_plugins_SUITE.erl
+++ b/apps/emqx/test/emqx_plugins_SUITE.erl
@@ -40,17 +40,11 @@ init_per_suite(Config) ->
     ct:pal("Executing ~s~n", [CmdPath]),
     ct:pal("~n ~s~n", [os:cmd(CmdPath)]),
 
-    put(loaded_file, filename:join([DataPath, "loaded_plugins"])),
     emqx_ct_helpers:boot_modules([]),
-    emqx_ct_helpers:start_apps([], fun(_) -> set_special_cfg(DataPath) end),
-
+    emqx_ct_helpers:start_apps([]),
+    emqx_config:put([plugins, expand_plugins_dir], DataPath),
     Config.
 
-set_special_cfg(PluginsDir) ->
-    application:set_env(emqx, plugins_loaded_file, get(loaded_file)),
-    application:set_env(emqx, expand_plugins_dir, PluginsDir),
-    ok.
-
 end_per_suite(_Config) ->
     emqx_ct_helpers:stop_apps([]).
 
@@ -62,8 +56,7 @@ t_load(_) ->
     ?assertEqual({error, not_started}, emqx_plugins:unload(emqx_mini_plugin)),
     ?assertEqual({error, not_started}, emqx_plugins:unload(emqx_hocon_plugin)),
 
-    application:set_env(emqx, expand_plugins_dir, undefined),
-    application:set_env(emqx, plugins_loaded_file, undefined).
+    emqx_config:put([plugins, expand_plugins_dir], undefined).
 
 t_load_ext_plugin(_) ->
     ?assertError({plugin_app_file_not_found, _},
diff --git a/apps/emqx/test/emqx_shared_sub_SUITE.erl b/apps/emqx/test/emqx_shared_sub_SUITE.erl
index 54a0de6d2..e3caf44a7 100644
--- a/apps/emqx/test/emqx_shared_sub_SUITE.erl
+++ b/apps/emqx/test/emqx_shared_sub_SUITE.erl
@@ -322,8 +322,8 @@ ensure_config(Strategy) ->
     ensure_config(Strategy, _AckEnabled = true).
 
 ensure_config(Strategy, AckEnabled) ->
-    application:set_env(emqx, shared_subscription_strategy, Strategy),
-    application:set_env(emqx, shared_dispatch_ack_enabled, AckEnabled),
+    emqx_config:put([broker, shared_subscription_strategy], Strategy),
+    emqx_config:put([broker, shared_dispatch_ack_enabled], AckEnabled),
     ok.
 
 subscribed(Group, Topic, Pid) ->
diff --git a/apps/emqx/test/emqx_sys_SUITE.erl b/apps/emqx/test/emqx_sys_SUITE.erl
index 29583524f..65f09caf6 100644
--- a/apps/emqx/test/emqx_sys_SUITE.erl
+++ b/apps/emqx/test/emqx_sys_SUITE.erl
@@ -25,8 +25,6 @@ all() -> emqx_ct:all(?MODULE).
 
 init_per_suite(Config) ->
     application:load(emqx),
-    ok = application:set_env(emqx, broker_sys_interval, 1),
-    ok = application:set_env(emqx, broker_sys_heartbeat, 1),
     ok = emqx_logger:set_log_level(emergency),
     Config.
 
diff --git a/apps/emqx/test/emqx_trie_SUITE.erl b/apps/emqx/test/emqx_trie_SUITE.erl
index 7ae23b4c6..51106f529 100644
--- a/apps/emqx/test/emqx_trie_SUITE.erl
+++ b/apps/emqx/test/emqx_trie_SUITE.erl
@@ -34,14 +34,14 @@ groups() ->
     [{compact, Cases}, {not_compact, Cases}].
 
 init_per_group(compact, Config) ->
-    emqx_trie:put_compaction_flag(true),
+    emqx_trie:set_compact(true),
     Config;
 init_per_group(not_compact, Config) ->
-    emqx_trie:put_compaction_flag(false),
+    emqx_trie:set_compact(false),
     Config.
 
 end_per_group(_, _) ->
-    emqx_trie:put_default_compaction_flag().
+    ok.
 
 init_per_suite(Config) ->
     application:load(emqx),
diff --git a/apps/emqx_gateway/test/emqx_sn_protocol_SUITE.erl b/apps/emqx_gateway/test/emqx_sn_protocol_SUITE.erl
index 7c7cce4fc..bf94acc16 100644
--- a/apps/emqx_gateway/test/emqx_sn_protocol_SUITE.erl
+++ b/apps/emqx_gateway/test/emqx_sn_protocol_SUITE.erl
@@ -65,9 +65,6 @@ init_per_suite(Config) ->
 end_per_suite(_) ->
     emqx_ct_helpers:stop_apps([emqx_gateway]).
 
-set_special_confs(emqx) ->
-    application:set_env(emqx, plugins_loaded_file,
-                        emqx_ct_helpers:deps_path(emqx, "test/emqx_SUITE_data/loaded_plugins"));
 set_special_confs(emqx_gateway) ->
     emqx_config:put(
       [emqx_gateway],
diff --git a/apps/emqx_telemetry/test/emqx_telemetry_SUITE.erl b/apps/emqx_telemetry/test/emqx_telemetry_SUITE.erl
new file mode 100644
index 000000000..1834ff375
--- /dev/null
+++ b/apps/emqx_telemetry/test/emqx_telemetry_SUITE.erl
@@ -0,0 +1,90 @@
+%%--------------------------------------------------------------------
+%% Copyright (c) 2020-2021 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.
+%%--------------------------------------------------------------------
+
+-module(emqx_telemetry_SUITE).
+
+-compile(export_all).
+-compile(nowarn_export_all).
+
+-include_lib("common_test/include/ct.hrl").
+-include_lib("eunit/include/eunit.hrl").
+-include_lib("snabbkaffe/include/snabbkaffe.hrl").
+
+-import(proplists, [get_value/2]).
+
+all() -> emqx_ct:all(?MODULE).
+
+init_per_testcase(_, Config) ->
+    emqx_ct_helpers:boot_modules(all),
+    emqx_ct_helpers:start_apps([emqx_telemetry]),
+    emqx_config:put([emqx_telemetry, enable], true),
+    Config.
+
+end_per_testcase(_, _Config) ->
+    emqx_ct_helpers:stop_apps([emqx_telemetry]).
+
+t_uuid(_) ->
+    UUID = emqx_telemetry:generate_uuid(),
+    Parts = binary:split(UUID, <<"-">>, [global, trim]),
+    ?assertEqual(5, length(Parts)),
+    {ok, UUID2} = emqx_telemetry:get_uuid(),
+    emqx_telemetry:stop(),
+    emqx_telemetry:start_link([{enabled, true}]),
+    {ok, UUID3} = emqx_telemetry:get_uuid(),
+    ?assertEqual(UUID2, UUID3).
+
+t_official_version(_) ->
+    true = emqx_telemetry:official_version("0.0.0"),
+    true = emqx_telemetry:official_version("1.1.1"),
+    true = emqx_telemetry:official_version("10.10.10"),
+    false = emqx_telemetry:official_version("0.0.0.0"),
+    false = emqx_telemetry:official_version("1.1.a"),
+    true = emqx_telemetry:official_version("0.0-alpha.1"),
+    true = emqx_telemetry:official_version("1.1-alpha.1"),
+    true = emqx_telemetry:official_version("10.10-alpha.10"),
+    false = emqx_telemetry:official_version("1.1-alpha.0"),
+    true = emqx_telemetry:official_version("1.1-beta.1"),
+    true = emqx_telemetry:official_version("1.1-rc.1"),
+    false = emqx_telemetry:official_version("1.1-alpha.a").
+
+t_get_telemetry(_) ->
+    {ok, TelemetryData} = emqx_telemetry:get_telemetry(),
+    OTPVersion = bin(erlang:system_info(otp_release)),
+    ?assertEqual(OTPVersion, get_value(otp_version, TelemetryData)),
+    {ok, UUID} = emqx_telemetry:get_uuid(),
+    ?assertEqual(UUID, get_value(uuid, TelemetryData)),
+    ?assertEqual(0, get_value(num_clients, TelemetryData)).
+
+t_enable(_) ->
+    ok = emqx_telemetry:enable(),
+    ?assertEqual(true, emqx_telemetry:is_enabled()),
+    ok = emqx_telemetry:disable(),
+    ?assertEqual(false, emqx_telemetry:is_enabled()).
+
+t_send_after_enable(_) ->
+    ok = emqx_telemetry:disable(),
+    ok = snabbkaffe:start_trace(),
+    try
+        ok = emqx_telemetry:enable(),
+        ?assertMatch({ok, _}, ?block_until(#{?snk_kind := telemetry_data_reported}, 2000, 100))
+    after
+        ok = snabbkaffe:stop()
+    end.
+
+bin(L) when is_list(L) ->
+    list_to_binary(L);
+bin(B) when is_binary(B) ->
+    B.