因为用nginx+lua去开发,所以会选择用最流行的开源方案,就是用OpenResty
nginx+lua打包在一起,而且提供了包括redis客户端,mysql客户端,http客户端在内的大量的组件
1、部署第一个nginx,作为应用层nginx
(1)部署openresty
mkdir -p /usr/servers
cd /usr/servers/
yum install -y readline-devel pcre-devel openssl-devel gcc
wget http://openresty.org/download/ngx_openresty-1.7.7.2.tar.gz
tar -xzvf ngx_openresty-1.7.7.2.tar.gz
cd /usr/servers/ngx_openresty-1.7.7.2/
cd bundle/LuaJIT-2.1-20150120/
make clean && make && make install
ln -sf luajit-2.1.0-alpha /usr/local/bin/luajit
cd bundle
wget https://github.com/FRiCKLE/ngx_cache_purge/archive/2.3.tar.gz
tar -xvf 2.3.tar.gz
cd bundle
wget https://github.com/yaoweibin/nginx_upstream_check_module/archive/v0.3.0.tar.gz
tar -xvf v0.3.0.tar.gz
cd /usr/servers/ngx_openresty-1.7.7.2
./configure --prefix=/usr/servers --with-http_realip_module --with-pcre --with-luajit --add-module=./bundle/ngx_cache_purge-2.3/ --add-module=./bundle/nginx_upstream_check_module-0.3.0/ -j2
make && make install
cd /usr/servers/
ll
/usr/servers/luajit
/usr/servers/lualib
/usr/servers/nginx
/usr/servers/nginx/sbin/nginx -V
启动nginx: /usr/servers/nginx/sbin/nginx
(2)nginx+lua开发的hello world
vi /usr/servers/nginx/conf/nginx.conf
在http部分添加:
lua_package_path "/usr/servers/lualib/?.lua;;";
lua_package_cpath "/usr/servers/lualib/?.so;;";
/usr/servers/nginx/conf下,创建一个lua.conf
server {
listen 80;
server_name _;
}
在nginx.conf的http部分添加:
include lua.conf;
验证配置是否正确:
/usr/servers/nginx/sbin/nginx -t
在lua.conf的server部分添加:
location /lua {
default_type 'text/html';
content_by_lua 'ngx.say("hello world")';
}
/usr/servers/nginx/sbin/nginx -t
重新nginx加载配置
/usr/servers/nginx/sbin/nginx -s reload
访问http: http://192.168.31.187/lua
vi /usr/servers/nginx/conf/lua/test.lua
ngx.say("hello world");
修改lua.conf
location /lua {
default_type 'text/html';
content_by_lua_file conf/lua/test.lua;
}
查看异常日志
tail -f /usr/servers/nginx/logs/error.log
(3)工程化的nginx+lua项目结构
项目工程结构
hello
hello.conf
lua
hello.lua
lualib
*.lua
*.so
放在/usr/hello目录下
/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/hello/lualib/?.lua;;";
lua_package_cpath "/usr/hello/lualib/?.so;;";
include /usr/hello/hello.conf;
}
/usr/hello/hello.conf
server {
listen 80;
server_name _;
location /lua {
default_type 'text/html';
lua_code_cache off;
content_by_lua_file /usr/example/lua/test.lua;
}
}
用eshop-cache01和eshop-cache02作为应用层nginx服务器,用eshop-cache03作为分发层nginx
在eshop-cache03,也就是分发层nginx中,编写lua脚本,完成基于商品id的流量分发策略
步骤:
1、获取请求参数,比如productId
2、对productId进行hash
3、hash值对应用服务器数量取模,获取到一个应用服务器
4、利用http发送请求到应用层nginx
5、获取响应后返回
作为一个流量分发的nginx,会发送http请求到后端的应用nginx上面去,所以要先引入lua http lib包
cd /usr/hello/lualib/resty/
wget https://raw.githubusercontent.com/pintsized/lua-resty-http/master/lib/resty/http_headers.lua
wget https://raw.githubusercontent.com/pintsized/lua-resty-http/master/lib/resty/http.lua
代码:
local uri_args = ngx.req.get_uri_args()
local productId = uri_args["productId"]
local hosts = {"192.168.31.187", "192.168.31.19"}
local hash = ngx.crc32_long(productId)
local index = (hash % 2) + 1
backend = "http://"..hosts[index]
local requestPath = uri_args["requestPath"]
requestPath = "/"..requestPath.."?productId="..productId
local http = require("resty.http")
local httpc = http.new()
local resp, err = httpc:request_uri(backend,{
method = "GET",
path = requestPath
})
if not resp then
ngx.say("request error: ", err)
return
end
ngx.say(resp.body)
httpc:close()
分发层nginx,lua应用,会将商品id,商品店铺id,都转发到后端的应用nginx
位置:/usr/servers/nginx/sbin/nginx -s reload
1、应用nginx的lua脚本接收到请求
2、获取请求参数中的商品id,以及商品店铺id
3、根据商品id和商品店铺id,在nginx本地缓存中尝试获取数据
4、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
cd /usr/hello/lualib/resty/
wget https://raw.githubusercontent.com/pintsized/lua-resty-http/master/lib/resty/http_headers.lua
wget https://raw.githubusercontent.com/pintsized/lua-resty-http/master/lib/resty/http.lua
5、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
6、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
7、nginx最终利用获取到的数据,动态渲染网页模板
cd /usr/hello/lualib/resty/
wget https://raw.githubusercontent.com/bungle/lua-resty-template/master/lib/resty/template.lua
mkdir /usr/hello/lualib/resty/html
cd /usr/hello/lualib/resty/html
wget https://raw.githubusercontent.com/bungle/lua-resty-template/master/lib/resty/template/html.lua
在hello.conf的server中配置模板位置
set $template_location "/templates";
set $template_root "/usr/hello/templates";
mkdir /usr/hello/templates
vi product.html
product id: {* productId *}<br/>
product name: {* productName *}<br/>
product picture list: {* productPictureList *}<br/>
product specification: {* productSpecification *}<br/>
product service: {* productService *}<br/>
product color: {* productColor *}<br/>
product size: {* productSize *}<br/>
shop id: {* shopId *}<br/>
shop name: {* shopName *}<br/>
shop level: {* shopLevel *}<br/>
shop good cooment rate: {* shopGoodCommentRate *}<br/>
8、将渲染后的网页模板作为http响应,返回给分发层nginx
hello.conf中:
lua_shared_dict my_cache 128m;
lua脚本中:
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://192.168.31.179:8080",{
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://192.168.31.179:8080",{
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)
第一次访问的时候,其实在nginx本地缓存中是取不到的,所以会发送http请求到后端的缓存服务里去获取,会从redis中获取
拿到数据以后,会放到nginx本地缓存里面去,过期时间是10分钟
然后将所有数据渲染到模板中,返回模板
以后再来访问的时候,就会直接从nginx本地缓存区获取数据了
缓存数据生产 -> 有数据变更 -> 主动更新两级缓存(ehcache+redis)-> 缓存维度化拆分
分发层nginx + 应用层nginx -> 自定义流量分发策略提高缓存命中率
nginx shared dict缓存 -> 缓存服务 -> redis -> ehcache -> 渲染html模板 -> 返回页面
如果你的数据在nginx -> redis -> ehcache三级缓存都不在了,可能就是被LRU清理掉了
这个时候缓存服务会重新拉去数据,去更新到ehcache和redis中