在nginx中使用lua直接访问mysql和memcaced达到数据接口的统一_MySQL

安装nginx参见《nginx+lua+redis构建高并发应用》

让nginx 中的nginx_lua_module支持mysql 和memcache

下载

https://github.com/agentzh/lua-resty-memcached

https://github.com/agentzh/lua-resty-mysql

对于访问接口的统一有很多的处理方式，这里介绍使用nginx lua 访问mysql并用memcache缓存起来。

配置如下：

...		location /getinfo {			default_type 'text/plain';			content_by_lua '				local args = ngx.req.get_uri_args()				if args["appleid"] == nil then					ngx.say("param appleid is nil")					return				end				local memcached = require "memcached"				local memc, err = memcached:new()				if not memc then					ngx.say("failed to instantiate memc: ", err)					return				end				memc:set_timeout(1000) -- 1 sec				local ok, err = memc:connect("172.16.18.114", 11211)				if not ok then					ngx.say("failed to connect: ", err)					return				end				local res, flags, err = memc:get(args["appleid"])				if err then					ngx.say("failed to get memc: ", err)					return				end				if not res then					local mysql = require "mysql"					local db, err = mysql:new()					if not db then						ngx.say("failed to instantiate mysql: ", err)						return					end					db:set_timeout(1000) -- 1 sec					local ok, err, errno, sqlstate = db:connect{						host = "172.16.18.162",						port = 3306,						database = "test",						user = "root",						password = "cpyf",						max_packet_size = 1024 * 1024					}					if not ok then						ngx.say("failed to connect: ", err, ": ", errno, " ", sqlstate)						return					end					-- ngx.say("connected to mysql.")					sql = "select * from tagval where tag = /'" .. args["appleid"] .. "/'"					res, err, errno, sqlstate = db:query(sql)					if not res then						ngx.say("bad result: ", err, ": ", errno, ": ", sqlstate, ".")						return					end					local json = require "json"					ngx.say("mysql found")					ngx.say(json.encode(res))					local ok, err = memc:set(args["appleid"], json.encode(res))					if not ok then						ngx.say("failed to set memc: ", err)						return					end					local ok, err = db:set_keepalive(0, 100)					if not ok then						ngx.say("failed to set keepalive: ", err)						return					end					return				end				ngx.say("memc found")				ngx.say(res)				memc:set_keepalive(0, 100)			';		}		...

第二次运行：

curl --gethttp://app.ca-sim.com/getinfo?appleid=jfy

mysql found[{"val":"123","tag":"jfy"}]

第二次后运行：

curl --gethttp://app.ca-sim.com/getinfo?appleid=jfy

memc found[{"val":"123","tag":"jfy"}]

结果已被缓存