亿级流量电商详情页系统实战-31.应用层nginx缓存实现

待我称王封你为后i 2022-10-29 03:24 172阅读 0赞

# 1.分发到应用层nginx流程 #

*  应用nginx的lua脚本接收到请求
 *  获取请求参数中的商品id，以及商品店铺id
 *  根据商品id和商品店铺id，在nginx本地缓存中尝试获取数据
 *  如果在nginx本地缓存中没有获取到数据，那么就到redis分布式缓存中获取数据，如果获取到了数据，还要设置到nginx本地缓存中
    
    但是这里有个问题，建议不要用nginx+lua直接去获取redis数据。因为openresty没有太好的redis cluster的支持包，所以建议是发送http请求到缓存数据生产服务，由该服务提供一个http接口，缓存数生产服务可以基于redis cluster api从redis中直接获取数据，并返回给nginx。
 *  如果缓存数据生产服务没有在redis分布式缓存中没有获取到数据，那么就在自己本地ehcache中获取数据，返回数据给nginx，也要设置到nginx本地缓存中
 *  如果ehcache本地缓存都没有数据，那么就需要去原始的服务中拉去数据，该服务会从mysql中查询，拉去到数据之后，返回给nginx，并重新设置到ehcache和redis中
 *  nginx最终利用获取到的数据，动态渲染网页模板

# 2.引入相关依赖 #

#cd /usr/servers/lualib/resty/ 
    #wget https://codechina.csdn.net/mirrors/pintsized/lua-resty-http/-/tree/master/lib/resty/http_headers.lua 
    #wget https://codechina.csdn.net/mirrors/pintsized/lua-resty-http/-/tree/master/lib/resty/http.lua 
    
    #wget https://github.com.com/bungle/lua-resty-template/master/lib/resty/template.lua
    #mkdir /usr/servers/lualib/resty/html
    #cd /usr/servers/lualib/resty/html
    #wget https://github.com/bungle/lua-resty-template/blob/master/lib/resty/template/html.lua

# 3.规划lua项目结构 #

/usr/lua/eshop
    eshop
        eshop.conf     
        lua              
          product.lua
        templates
          product.html
        lualib            
          *.lua
          *.so

# 4.在nginx中配置eshop.conf #

# vi /usr/servers/nginx/conf/nginx.conf
    
    worker_processes  2;  
    
    error_log  logs/error.log;  
    
    events {   
        worker_connections  1024;  
    }  
    
    http {   
        include       mime.types;  
        default_type  text/html;  
      
        lua_package_path "/usr/servers/lualib/?.lua;;";  
        lua_package_cpath "/usr/servers/lualib/?.so;;"; 
        lua_shared_dict my_cache 128m;
        include /usr/lua/eshop/eshop.conf;  
    }

# 5.配置eshop.conf #

#mkdir -p /usr/lua/eshop/
    #vi /usr/lua/eshop/eshop.conf
    server {   
        listen       80;  
        server_name  _;  
        set $template_location "/templates";  
        set $template_root "/usr/lua/eshop/templates";
        location /product{   
            default_type 'text/html';  
            content_by_lua_file /usr/lua/eshop/lua/proudct.lua;  
        }  
    }

# 6.编写product.html #

#mkdir -p /usr/lua/eshop/templates
 #vi /usr/lua/eshop/templates/product.html
 <html>
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>商品详情页</title>
 </head>
 <body>
 商品id: { * productId *} 
 商品名称: { * productName *} 
 商品图片列表: { * productPictureList *} 
 商品规格: { * productSpecification *} 
 商品售后服务: { * productService *} 
 商品颜色: { * productColor *} 
 商品大小: { * productSize *} 
 店铺id: { * shopId *} 
 店铺名称: { * shopName *} 
 店铺等级: { * shopLevel *} 
 店铺好评率: { * shopGoodCommentRate *} 
 </body>
 </html>

# 7.编写produc.lua #

# mkdir -p /usr/lua/eshop/lua
    # vi /usr/lua/eshop/lua/produc.lua
    
    local uri_args = ngx.req.get_uri_args()
    local productId = uri_args["productId"]
    local shopId = uri_args["shopId"]
    
    local cache_ngx = ngx.shared.my_cache
    
    local productCacheKey = "product_info_"..productId
    local shopCacheKey = "shop_info_"..shopId
    
    local productCache = cache_ngx:get(productCacheKey)
    local shopCache = cache_ngx:get(shopCacheKey)
    
    if productCache == "" or productCache == nil then
    	local http = require("resty.http")
    	local httpc = http.new()
    
    	local resp, err = httpc:request_uri("http://192.168.9.253:8080",{ 
      		method = "GET",
      		path = "/getProductInfo?productId="..productId
    	})
    
    	productCache = resp.body
    	cache_ngx:set(productCacheKey, productCache, 10 * 60)
    end
    
    if shopCache == "" or shopCache == nil then
    	local http = require("resty.http")
    	local httpc = http.new()
    
    	local resp, err = httpc:request_uri("http://192.168.9.253:8080",{ 
      		method = "GET",
      		path = "/getShopInfo?shopId="..shopId
    	})
    
    	shopCache = resp.body
    	cache_ngx:set(shopCacheKey, shopCache, 10 * 60)
    end
    
    local cjson = require("cjson")
    local productCacheJSON = cjson.decode(productCache)
    local shopCacheJSON = cjson.decode(shopCache)
    
    local context = { 
    	productId = productCacheJSON.id,
    	productName = productCacheJSON.name,
    	productPrice = productCacheJSON.price,
    	productPictureList = productCacheJSON.pictureList,
    	productSpecification = productCacheJSON.specification,
    	productService = productCacheJSON.service,
    	productColor = productCacheJSON.color,
    	productSize = productCacheJSON.size,
    	shopId = shopCacheJSON.id,
    	shopName = shopCacheJSON.name,
    	shopLevel = shopCacheJSON.level,
    	shopGoodCommentRate = shopCacheJSON.goodCommentRate
    }
    
    local template = require("resty.template")
    template.render("product.html", context)

# 8.nginx动态生效 #

/usr/servers/nginx/sbin/nginx -s reload

# 9.测试 #

http://192.168.135.135/eshop?method=product&productId=1&shopId=1