文章目录

  • 一、Redis服务
  • 二、Redis缓存预热
      • 1. 引入依赖
      • 2. handler类实现
  • 三、整合Redis缓存
  • 四、运行
  • 五、测试
      • 1. redis缓存预热
      • 2. redis缓存命中
  • 六、高可用集群

通过本文章，可以完成多级缓存架构中的Redis缓存。

一、Redis服务

在docker/docker-compose.yml中，添加redis服务块

redis:container_name: redisimage: redis:7.2volumes:- ./redis/redis.conf:/usr/local/etc/redis/redis.confports:- "6379:6379"command: ["redis-server", "/usr/local/etc/redis/redis.conf"]networks:multi-cache:ipv4_address: 172.30.3.21

二、Redis缓存预热

在spirngboot项目启动时，将固定的热点数据提前加载到redis中。

1. 引入依赖

pom.xml添加如下依赖

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId></dependency><dependency><groupId>io.lettuce</groupId><artifactId>lettuce-core</artifactId><version>6.1.4.RELEASE</version> </dependency><dependency><groupId>com.alibaba.fastjson2</groupId><artifactId>fastjson2</artifactId><version>2.0.41</version></dependency>

application.yml添加如下配置

spring:redis:host: 172.30.3.21

2. handler类实现

新建config.RedisHandler类，内容如下，主要是重写afterPropertiesSet，完成缓存预热逻辑，saveItem和deleteItemById函数给之后的章节使用。

@Componentpublic class RedisHandler implements InitializingBean {@Autowiredprivate StringRedisTemplate redisTemplate;@Autowiredprivate IItemService itemService;@Autowiredprivate IItemStockService stockService;@Overridepublic void afterPropertiesSet() throws Exception {List<Item> itemList = itemService.list();for (Item item : itemList) {String json = JSON.toJSONString(item);redisTemplate.opsForValue().set("item:id:"+item.getId(), json);}List<ItemStock> stockList = stockService.list();for (ItemStock stock : stockList) {String json = JSON.toJSONString(stock);redisTemplate.opsForValue().set("item:stock:id:"+stock.getId(), json);}}public void saveItem(Item item){String json = JSON.toJSONString(item);redisTemplate.opsForValue().set("item:id:"+item.getId(), json);}public void deleteItemById(Long id){redisTemplate.delete("item:id:"+id);}}

三、整合Redis缓存


改进openresty的docker/openresty1/lualib/common.lua，如下

local redis = require('resty.redis')local red = redis:new()red:set_timeouts(1000, 1000, 1000)-- 创建一个本地缓存对象item_cachelocal item_cache = ngx.shared.item_cache;-- 关闭redis连接的工具方法，其实是放入连接池local function close_redis(red)local pool_max_idle_time = 10000 -- 连接的空闲时间，单位是毫秒local pool_size = 100 --连接池大小local ok, err = red:set_keepalive(pool_max_idle_time, pool_size)if not ok thenngx.log(ngx.ERR, "放入redis连接池失败: ", err)endend-- 查询redis的方法 ip和port是redis地址，key是查询的keylocal function read_redis(ip, port, key)-- 获取一个连接local ok, err = red:connect(ip, port)if not ok thenngx.log(ngx.ERR, "连接redis失败 : ", err)return nilend-- 查询redislocal resp, err = red:get(key)-- 查询失败处理if not resp thenngx.log(ngx.ERR, "查询Redis失败: ", err, ", key = " , key)end--得到的数据为空处理if resp == ngx.null thenresp = nilngx.log(ngx.ERR, "查询Redis数据为空, key = ", key)endclose_redis(red)return respend-- 函数，向openresty本身发送类似/path/item/10001请求，根据conf配置，将被删除/path前缀并代理至tomcat程序local function read_get(path, params)local rsp = ngx.location.capture('/path'..path,{method = ngx.HTTP_GET,args = params,})if not rsp thenngx.log(ngx.ERR, "http not found, path: ", path, ", args: ", params);ngx.exit(404)endreturn rsp.bodyend-- 函数，如果本地有缓存，使用缓存，如果没有代理到tomcat然后将数据存入缓存local function read_data(key, expire, path, params)-- query local cachelocal rsp = item_cache:get(key)-- query redisif not rsp thenngx.log(ngx.ERR, "local cache miss, try redis, key: ", key)rsp = read_redis("172.30.3.21", 6379, key)if not rsp thenngx.log(ngx.ERR, "redis cache miss, try tomcat, key: ", key)rsp = read_get(path, params)endend-- write into local cacheitem_cache:set(key, rsp, expire)return rspendlocal _M = {read_get = read_get,read_redis = read_redis,read_data = read_data}return _M

item.lua不需要用改动。

四、运行

到此为止，docker-compose.yml内容应该如下

version: '3.8'networks:multi-cache:driver: bridgeipam:driver: defaultconfig:- subnet: 172.30.3.0/24services:mysql:container_name: mysqlimage: mysql:8volumes:- ./mysql/conf/my.cnf:/etc/mysql/conf.d/my.cnf- ./mysql/data:/var/lib/mysql- ./mysql/logs:/logsports:- "3306:3306"environment:- MYSQL_ROOT_PASSWORD=1009networks:multi-cache:ipv4_address: 172.30.3.2nginx:container_name: nginximage: nginx:stablevolumes:- ./nginx/conf/nginx.conf:/etc/nginx/nginx.conf- ./nginx/conf/conf.d/default.conf:/etc/nginx/conf.d/default.conf- ./nginx/dist:/usr/share/nginx/distports:- "8080:8080"networks:multi-cache:ipv4_address: 172.30.3.3openresty1:container_name: openresty1image: openresty/openresty:1.21.4.3-3-jammy-amd64volumes:- ./openresty1/conf/nginx.conf:/usr/local/openresty/nginx/conf/nginx.conf- ./openresty1/conf/conf.d/default.conf:/etc/nginx/conf.d/default.conf- ./openresty1/lua:/usr/local/openresty/nginx/lua- ./openresty1/lualib/common.lua:/usr/local/openresty/lualib/common.luanetworks:multi-cache:ipv4_address: 172.30.3.11redis:container_name: redisimage: redis:7.2volumes:- ./redis/redis.conf:/usr/local/etc/redis/redis.confports:- "6379:6379"command: [ "redis-server", "/usr/local/etc/redis/redis.conf" ]networks:multi-cache:ipv4_address: 172.30.3.21

删除原来的multiCache，重新启动各项服务。

docker-compose -p multi-cache up -d

启动springboot程序。

五、测试

1. redis缓存预热

springboot程序启动后，出现查询日志，查看redis数据库发现自动存入了数据。

2. redis缓存命中

清空openresty容器日志，访问http://localhost:8080/item.html" />2024-01-12 16:06:18 2024/01/12 08:06:18 [error] 7#7: *1 [lua] common.lua:59: read_data(): local cache miss, try redis, key: item:id:10001, client: 172.30.3.3, server: localhost, request: "GET /api/item/10001 HTTP/1.0", host: "nginx-cluster", referrer: "http://localhost:8080/item.html?id=10001"2024-01-12 16:06:18 2024/01/12 08:06:18 [error] 7#7: *1 [lua] common.lua:59: read_data(): local cache miss, try redis, key: item:stock:id:10001, client: 172.30.3.3, server: localhost, request: "GET /api/item/10001 HTTP/1.0", host: "nginx-cluster", referrer: "http://localhost:8080/item.html?id=10001"2024-01-12 16:06:18 172.30.3.3 - - [12/Jan/2024:08:06:18 +0000] "GET /api/item/10001 HTTP/1.0" 200 466 "http://localhost:8080/item.html?id=10001" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Safari/537.36 Edg/121.0.0.0"

查看springboot程序日志，也没有查询记录，说明redis缓存命中成功。

六、高可用集群


对于redis高可用集群，可以参考以下专栏文章。
https://blog.csdn.net/m0_51390969/category_12546314.html?spm=1001.2014.3001.5482