some changes

 local lrucache = require "resty.lrucache"
-local switch_controller = require "switch_controller"
 
 -- init redis twemproxy config
 
@@ -21,8 +20,5 @@ lua_context.lua_conf_cache=ngx.shared.ngxconf
 
 lua_context.configs={}
 
---- init switch to aws percentage
-switch_controller.init()
-
 ngx.shared.upstream:flush_all()
 ngx.shared.upstream:flush_expired()

@@ -16,6 +16,9 @@ function M:switch()
 
    if method == "query" then
        local percentage = lua_context.lua_conf_cache:get("switch:percentage")
+       if not percentage then
+        percentage = '0'
+       end
        ngx.say(percentage)
        ngx.exit(ngx.HTTP_OK)
   
@@ -35,13 +38,15 @@ function M:switch()
      lua_context.lua_conf_cache:set("switch:uid", uid)
      ngx.exit(ngx.HTTP_OK)
     end
- end
-end 
-
-function M:init()
-   return lua_context.lua_conf_cache:set("switch:percentage", 0)
- end
+   end
 
+      --- reset all
+   if method == "reset" then
+         lua_context.lua_conf_cache:delete("switch:uid")
+         lua_context.lua_conf_cache:delete("switch:percentage")
+         ngx.exit(ngx.HTTP_OK)
+   end
+end 
  
 function M:get_percentage()
   local per =  lua_context.lua_conf_cache:get("switch:percentage")

@@ -15,6 +15,15 @@
 
 
 
+##  切换
+
+ - `重置`: http://erp.yoho.yohoops.org/switch?method=reset
+ - `查询`:  http://erp.yoho.yohoops.org/switch?method=query
+ - `设置UID强制到aws`:  http://erp.yoho.yohoops.org/switch?method=force&uid=50873076
+ - `设置按照比率切换到aws`: http://erp.yoho.yohoops.org/switch?method=switch&percentage=10
+
+
+
 ## 动态`upstream`的支持
 
 基于 [lua-upstream-nginx-module] (https://github.com/openresty/lua-upstream-nginx-module) 动态设置upstream的 `up`, `down`