lapis and lua-resty-balancer attempt to index local 'app_cls' (a userdata value)

winlia520 · 2019-08-21T17:55:52+00:00

Yes, you were all correct.I was using the API in a bad way. I was using syntax i would normally use in lua, as if it was an array. so instead of metadata[ind...

lapis and lua-resty-balancer attempt to index local 'app_cls' (a userdata value)

winlia520

I have ab test requirement

If when I have 10 different versions of the web to buy the page style
I need to set a different weight ratio for each page.

I want to use the lua-resty-balancer module to configure the access ratio for different pages.

Each page has a different id, and each id has a different weight. When nginx receives a user request, it automatically assigns a page id proportionally.

The following code is executed by me in the init_by_lua phase

local _M = {}
_M.VERSION = '0.10'
local mt = { __index = _M }

 local resty_chash = require "resty.chash"
local resty_roundrobin = require "resty.roundrobin"
		
 ---page ID = weigth %
local page_list = {
	["1985"] = 5,
	["1986"] = 3,
	["1987"] = 2,
}
@leafo  

-- XX: we can do the following steps to keep consistency with nginx chash
local str_null = string.char(0)

local pages, nodes = {}, {}
for cid, weight in pairs(page_list) do
	-- XX: we can just use serv as id when we doesn't need keep consistency with nginx chash
	local id = string.gsub(cid, ":", str_null)
    pages[id] = cid
	nodes[id] = weight
end

 
local rr_up = resty_roundrobin:new(page_list)
package.loaded.my_rr_up = rr_up  


 
local chash_up = resty_chash:new(nodes)
package.loaded.my_chash_up = chash_up
package.loaded.my_cids = pages

II want to get the my_rr_up module in the controller layer

local chash_up = package.loaded.my_chash_up

When running the request, the following error is reported.

2019/08/20 10:11:09 [error] 78194#78194: *2 lua entry thread aborted: runtime error: /usr/local/share/lua/5.1/lapis/init.lua:17: attempt to index local 'app_cls' (a userdata value)
stack traceback:
coroutine 0:
/usr/local/share/lua/5.1/lapis/init.lua: in function 'serve'

/usr/local/share/lua/5.1/lapis/init.lua

local application = require("lapis.application")
local Application
Application = application.Application
local app_cache = { }
setmetatable(app_cache, {
 __mode = "k"
})
local dispatcher
local serve
serve = function(app_cls)
 local app = app_cache[app_cls]
 if not (app) then
 local name = app_cls
 if type(name) == "string" then
 app_cls = require(name)
 end
 if app_cls.__base then
 app = app_cls()
 else
 app_cls:build_router()
 app = app_cls
 end
 app_cache[name] = app
 end
 if not (dispatcher) then
 dispatcher = require("lapis.nginx")
 end
 return dispatcher.dispatch(app)
end
return {
 serve = serve,
 application = application,
 Application = Application,
 app_cache = app_cache
}

 