diff --git a/rel/files/emqttd.config b/rel/files/emqttd.config
index 357189be0..b4681e448 100644
--- a/rel/files/emqttd.config
+++ b/rel/files/emqttd.config
@@ -87,9 +87,6 @@
         ]},
         %% Session
         {session, [
-            %% Expired after 2 days
-            {expired_after, 48},
-
             %% Max number of QoS 1 and 2 messages that can be “in flight” at one time.
             %% 0 means no limit
             {max_inflight, 100},
@@ -104,7 +101,13 @@
             {await_rel_timeout, 8},
 
             %% Max Packets that Awaiting PUBREL, 0 means no limit
-            {max_awaiting_rel, 0}
+            {max_awaiting_rel, 0},
+
+            %% Statistics Collection Interval(seconds)
+            {collect_interval, 10},
+
+            %% Expired after 2 days
+            {expired_after, 48}
 
         ]},
         %% Session