diff --git a/Makefile b/Makefile
index 659126c0d..c1a173c07 100644
--- a/Makefile
+++ b/Makefile
@@ -5,7 +5,7 @@ BASE_DIR = $(shell pwd)
 REBAR    = $(BASE_DIR)/rebar
 DIST	 = $(BASE_DIR)/rel/$(APP)
 
-all: submods compile
+all: compile
 
 submods:
 	@git submodule update --init
diff --git a/include/emqttd.hrl b/include/emqttd.hrl
index b68b583f0..cb849d246 100644
--- a/include/emqttd.hrl
+++ b/include/emqttd.hrl
@@ -124,7 +124,8 @@
     dup    = false  :: boolean(),             %% Dup flag
     sys    = false  :: boolean(),             %% $SYS flag
     payload         :: binary(),              %% Payload
-    timestamp       :: erlang:timestamp()     %% os:timestamp
+    timestamp       :: erlang:timestamp(),    %% os:timestamp
+    extra  = []     :: list()
 }).
 
 -type mqtt_message() :: #mqtt_message{}.
diff --git a/plugins/emqplus_backend_cassa b/plugins/emqplus_backend_cassa
deleted file mode 160000
index 62c52536a..000000000
--- a/plugins/emqplus_backend_cassa
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 62c52536a4263fa2735478420b8e78b8f494be2a
diff --git a/plugins/emqplus_backend_mongo b/plugins/emqplus_backend_mongo
deleted file mode 160000
index 8a7b5cc03..000000000
--- a/plugins/emqplus_backend_mongo
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 8a7b5cc03f1e55cfd6d50ed1a7161ecd8a4a14be
diff --git a/plugins/emqplus_backend_mysql b/plugins/emqplus_backend_mysql
deleted file mode 160000
index c7bebfe62..000000000
--- a/plugins/emqplus_backend_mysql
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit c7bebfe62a208284cb38cab89f2fd6d73968aa33
diff --git a/plugins/emqplus_backend_pgsql b/plugins/emqplus_backend_pgsql
deleted file mode 160000
index 92825dea5..000000000
--- a/plugins/emqplus_backend_pgsql
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 92825dea51e3debf68a2387e66bae27d375975f8
diff --git a/plugins/emqplus_backend_redis b/plugins/emqplus_backend_redis
deleted file mode 160000
index 4e9c1a234..000000000
--- a/plugins/emqplus_backend_redis
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 4e9c1a234d35561c6227f0e6ff98a612fab50ec4
diff --git a/plugins/emqttd_dashboard b/plugins/emqttd_dashboard
deleted file mode 160000
index 0a5983510..000000000
--- a/plugins/emqttd_dashboard
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 0a59835106c7672699da7c2f9deb576678fdb37e
diff --git a/plugins/emqttd_plugin_mysql b/plugins/emqttd_plugin_mysql
deleted file mode 160000
index d714c7598..000000000
--- a/plugins/emqttd_plugin_mysql
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit d714c759804f9528f187fadd544912e37fd664b0
diff --git a/plugins/emqttd_plugin_pgsql b/plugins/emqttd_plugin_pgsql
deleted file mode 160000
index 81f0164a3..000000000
--- a/plugins/emqttd_plugin_pgsql
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 81f0164a339044d329c3179f922df332ae102696
diff --git a/plugins/emqttd_plugin_redis b/plugins/emqttd_plugin_redis
deleted file mode 160000
index 9fef7a1b7..000000000
--- a/plugins/emqttd_plugin_redis
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 9fef7a1b762dfd8ad27190ebe31dd3afc784c6fa
diff --git a/plugins/emqttd_plugin_template b/plugins/emqttd_plugin_template
deleted file mode 160000
index 6e1382b63..000000000
--- a/plugins/emqttd_plugin_template
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 6e1382b63096cc3259f7edc6c26adc571ee53d74
diff --git a/plugins/emqttd_recon b/plugins/emqttd_recon
deleted file mode 160000
index eb4a03d90..000000000
--- a/plugins/emqttd_recon
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit eb4a03d90f932839bdad9aa5703de7731169ce66
diff --git a/plugins/emqttd_stomp b/plugins/emqttd_stomp
deleted file mode 160000
index b8b5393ec..000000000
--- a/plugins/emqttd_stomp
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit b8b5393ecda9617a2b724dae0ab431d368963ca4