diff --git a/layout.txt b/layout.txt
index 9585855..1053a0d 100644
--- a/layout.txt
+++ b/layout.txt
@@ -4,8 +4,8 @@
 
                                              ----------------------
                                     |--------| web1/apache/centos |--------|        -----------------------
--------------------------------     |        ----------------------        |--------| db01/centos/mariadb |
-| ha01/haproxy/acme.sh/centos |-----|                                      |        -----------------------
--------------------------------     |        ----------------------        |--------| cache01/debian/redis|
-                                    |--------| web2/nginx/debian  |--------|        -----------------------
+-------------------------------     |        ----------------------        |--------| db01/centos/mariadb |--------
+| ha01/haproxy/acme.sh/centos |-----|                                      |        -----------------------        |      --------------------------------
+-------------------------------     |        ----------------------        |--------| cache01/debian/redis|        |------| db02/centos/mariadb/ro_slave |
+                                    |--------| web2/nginx/debian  |--------|        -----------------------               --------------------------------
                                              ----------------------