diff --git a/apps/emqx_authz/src/emqx_authz_api_schema.erl b/apps/emqx_authz/src/emqx_authz_api_schema.erl
index b9e6b2def..fb643e9b7 100644
--- a/apps/emqx_authz/src/emqx_authz_api_schema.erl
+++ b/apps/emqx_authz/src/emqx_authz_api_schema.erl
@@ -182,8 +182,7 @@ definitions() ->
             mongo_type => #{type => string,
                             enum => [<<"rs">>],
                             example => <<"rs">>},
-            servers => #{type => array,
-                         items => #{type => string,example => <<"127.0.0.1:27017">>}},
+            servers => #{type => string, example => <<"127.0.0.1:27017, 127.0.0.2:27017">>},
             replica_set_name => #{type => string},
             pool_size => #{type => integer},
             username => #{type => string},
@@ -240,8 +239,7 @@ definitions() ->
             mongo_type => #{type => string,
                             enum => [<<"sharded">>],
                             example => <<"sharded">>},
-            servers => #{type => array,
-                         items => #{type => string,example => <<"127.0.0.1:27017">>}},
+            servers => #{type => string,example => <<"127.0.0.1:27017, 127.0.0.2:27017">>},
             pool_size => #{type => integer},
             username => #{type => string},
             password => #{type => string},
@@ -401,8 +399,7 @@ definitions() ->
                 type => string,
                 example => <<"HGETALL mqtt_authz">>
             },
-            servers => #{type => array,
-                         items => #{type => string,example => <<"127.0.0.1:3306">>}},
+            servers => #{type => string, example => <<"127.0.0.1:6379, 127.0.0.2:6379">>},
             redis_type => #{type => string,
                             enum => [<<"sentinel">>],
                             example => <<"sentinel">>},
@@ -438,8 +435,7 @@ definitions() ->
                 type => string,
                 example => <<"HGETALL mqtt_authz">>
             },
-            servers => #{type => array,
-                         items => #{type => string, example => <<"127.0.0.1:3306">>}},
+            servers => #{type => string, example => <<"127.0.0.1:6379, 127.0.0.2:6379">>},
             redis_type => #{type => string,
                             enum => [<<"cluster">>],
                             example => <<"cluster">>},