SpringBoot集成Redis+Lua限流

[TOC] # 目录 ## Lua 初步认识 ### Lua 特点 - 短小精干 - 嵌套式开发、插件开发 - 完美继承Redis [Redis内置Lua解释器执行过程原子性脚本预编译] ### IDEA插件安装 - Lua - EmmyLua ### Lua基本用法 - Hello Lua - 一个简易脚本(Lua入门级语法) ### [安装Lua](windows下配置lua开发环境) 1. [下载 Windows x86](http://luadist.org/), 如果是MAC推荐使用brew工具直接install lua 1. 安装IDEA插件, 搜索lua, 然后就选择同名插件lua. idea restart. 1. 配置Lua SDK的位置： IDEA -> File -> Project Structure 选择添加Lua 或者 EmmyLua, 路径指向Lua SDK的bin文件夹. ### 脚本显示 #### Hello Lua 演示 <details> <summary>点击查看</summary> ```lua --- --- Generated by EmmyLua(https://github.com/EmmyLua) --- Created by Administrator. --- DateTime: 2020/12/24 9:06 --- print('Hello Lua') ``` </details> #### 限流脚本演示 <details> <summary>点击查看</summary> ```lua --- 模拟限流 --- Generated by EmmyLua(https://github.com/EmmyLua) --- Created by Administrator. --- DateTime: 2020/12/24 9:08 --- --- 用于限流的Key local key = 'My Key' --- 限流的最大阔值 =2 local limit = 2 --- 当前流量大小 local currentLimit = 0 --- 是否大于限流标准 if currentLimit + 1 > limit then print('reject') return false else print('accept') return true end ``` </details> #### Redis预加载Lua <details> <summary>点击查看</summary> - 在Redis中执行Lua脚本 - Lua脚本预导入Redis ```shell [root@8_100 ~]# docker exec -it redis sh /data # cd /usr/local/bin /usr/local/bin # ./redis-cli # Hello 打印 127.0.0.1:6379> eval "return 'hello redis+lua'" 0 "hello redis+lua" # 参数传递 127.0.0.1:6379> eval "return {KEYS[1],ARGV[1]}" 2 K1 K2 V1 V2 1) "K1" 2) "V1" 127.0.0.1:6379> eval "return {KEYS[2],ARGV[2]}" 2 K1 K2 V1 V2 1) "K2" 2) "V2" # 预加载 127.0.0.1:6379> script load "return 'hello redis+lua'" "53b2700be01e76aa1b060e09c828dae642520f2e" 127.0.0.1:6379> evalsha "53b2700be01e76aa1b060e09c828dae642520f2e" 0 "hello redis+lua" # 预加载 127.0.0.1:6379> script load "return 'hello lua '..KEYS[1]" "1689a78376800076aa8b094894d8e7f7ab78f710" # 根据ID查看脚本是否存在 127.0.0.1:6379> script exists "1689a78376800076aa8b094894d8e7f7ab78f710" 1) (integer) 1 # 运行预加载给出的ID获取值 127.0.0.1:6379> evalsha "1689a78376800076aa8b094894d8e7f7ab78f710" 1 key1 val1 "hello lua key1" # 清空所有脚本缓存 127.0.0.1:6379> script flush OK ``` </details> ## Redis + Lua 限流组件封装 (一) - 编写Lua限流脚本 - spring-data-redis组件继承Lua和Redis - DefaultRedisScript加载Lua脚本 - RedisTemplate配置（调用Redis） - 在Controller中添加测试方法验证限流效果 ### 基础版 #### 引用接口方式 <details> <summary>点击查看</summary> **新建 ratelimiter-annotation 项目, 作为限流功能引用** Maven ```xml <?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.4.0</version> <relativePath/>  </parent> <groupId>com.example</groupId> <artifactId>ratelimiter-annotation</artifactId> <version>1.0-SNAPSHOT</version> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-redis</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-aop</artifactId> </dependency> <dependency> <groupId>com.google.guava</groupId> <artifactId>guava</artifactId> <version>18.0</version> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <optional>true</optional> </dependency> </dependencies> </project> ``` src/main/resources/ratelimiter.lua ```lua --- --- Generated by EmmyLua(https://github.com/EmmyLua) --- Created by eddie.lee --- DateTime: 2020/12/24 15:49 --- -- 获取方法签名特征 local methodKey = KEYS[1] redis.log(redis.LOG_DEBUG, 'key is', methodKey) -- 调用脚本传入的限流大小 local limit = tonumber(ARGV[1]) -- 获取当前流量大小 local count = tonumber(redis.call('get', methodKey) or "0") -- 是否超出限流阈值 if count + 1 > limit then -- 拒绝服务访问 return false else -- 没有超过阈值 -- 设置当前访问的数量+1 redis.call("INCRBY", methodKey, 1) -- 设置过期时间 redis.call("EXPIRE", methodKey, 1) -- 放行 return true end ``` src/main/java/com/example/springcloud/RedisConfiguration.java ```java @Configuration public class RedisConfiguration { // 如果本地也配置了StringRedisTemplate，可能会产生冲突 // 可以指定@Primary，或者指定加载特定的@Qualifier @Bean public RedisTemplate<String, String> redisTemplate(RedisConnectionFactory factory) { return new StringRedisTemplate(factory); } @Bean public DefaultRedisScript loadRedisScript() { DefaultRedisScript redisScript = new DefaultRedisScript(); redisScript.setLocation(new ClassPathResource("ratelimiter.lua")); redisScript.setResultType(java.lang.Boolean.class); return redisScript; } } ``` src/main/java/com/example/springcloud/AccessLimiter.java ```java @Slf4j @Service public class AccessLimiter { @Autowired private StringRedisTemplate stringRedisTemplate; @Autowired private RedisScript<Boolean> rateLimitLua; public void limitAccess(String key, Integer limit) { // step 1 : request Lua script boolean acquired = stringRedisTemplate.execute( rateLimitLua, // Lua script的真身 Lists.newArrayList(key), // Lua脚本中的Key列表 limit.toString() // Lua脚本Value列表 ); if (!acquired) { log.info("您的访问被阻塞了! key=[{}]", key); throw new RuntimeException("您的访问被阻塞了!"); } } } ``` **新建 ratelimiter-test 项目, 作为限流调用方** 1. ratelimiter-annotation 项目打包 mvn clean package 1. IDEA File --> Project Structure --> Libranies + --> Java (ratelimiter-annotation-1.0-SNAPSHOT.jar) Maven依赖 ```xml <?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.4.0</version> <relativePath/>  </parent> <groupId>com.example</groupId> <artifactId>ratelimiter-test</artifactId> <version>1.0-SNAPSHOT</version> <packaging>jar</packaging> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <optional>true</optional> </dependency>  <dependency> <groupId>${project.groupId}</groupId> <artifactId>ratelimiter-annotation</artifactId> <version>${project.version}</version> </dependency> </dependencies> </project> ``` src/main/resources/application.yml ```yaml spring: application: name: ratelimiter-test redis: database: 0 host: 192.168.8.100 port: 6379 server: port: 10086 logging: file: path: log/${spring.application.name}.log ``` src/main/java/com/example/springcloud/Controller.java ```java @Slf4j @RestController public class Controller { @Autowired private AccessLimiter accessLimiter; @GetMapping("test") public String test() { accessLimiter.limitAccess("ratelimiter-test", 1); return "success"; } } ``` src/main/java/com/example/springcloud/Controller.java ```java @SpringBootApplication public class RatelimiterApplication { public static void main(String[] args) { new SpringApplicationBuilder(RatelimiterApplication.class) .web(WebApplicationType.SERVLET) .run(args); } } ``` 访问测试 ```xml 1. GET localhost:10086/test 2. 疯狂点击当超过Lua脚本的阈值就会出现错误： { "timestamp": "2020-12-25T05:44:30.665+00:00", "status": 500, "error": "Internal Server Error", "message": "", "path": "/test" } 后台也会打印： 2020-12-25 13:44:30.662 INFO 19044 --- [io-10086-exec-7] com.example.springcloud.AccessLimiter : 您的访问被阻塞了! key=[ratelimiter-test] java.lang.RuntimeException: 您的访问被阻塞了! ``` </details> ### 升级高大尚版 #### 自定义注解方式引用 - 基于Aspectj创建自定义注解AccessLimit - 配置限流规则的切面 - 为目标方法添加@AccessLimit注解, 验证效果 <details> <summary>点击查看</summary> ***继续使用上面的代码延伸*** ratelimiter-annotation com.example.springcloud.annotation.AccessLimiter ```java /** * @author eddie.lee * @ProjectName ratelimiter-annotation * @Package com.example.springcloud.annotation * @ClassName AccessLimiter * @description * @date created in 2020-12-25 11:26 * @modified by */ @Target({ElementType.METHOD}) @Retention(RetentionPolicy.RUNTIME) @Documented public @interface AccessLimiter { int limit(); String methodKey() default ""; } ``` com.example.springcloud.annotation.AccessLimiterAspect ```java /** * @author eddie.lee * @ProjectName ratelimiter-annotation * @Package com.example.springcloud * @ClassName AccessLimiterAspect * @description * @date created in 2020-12-25 11:25 * @modified by */ @Slf4j @Aspect @Component public class AccessLimiterAspect { @Autowired private StringRedisTemplate stringRedisTemplate; @Autowired private RedisScript<Boolean> rateLimitLua; @Pointcut("@annotation(com.example.springcloud.annotation.AccessLimiter)") public void cut() { log.info("cut"); } @Before("cut()") public void before(JoinPoint joinPoint) { // 1. 获得方法签名，作为method Key MethodSignature signature = (MethodSignature) joinPoint.getSignature(); Method method = signature.getMethod(); AccessLimiter annotation = method.getAnnotation(AccessLimiter.class); if (annotation == null) { return; } String key = annotation.methodKey(); Integer limit = annotation.limit(); // 如果没设置methodkey, 从调用方法签名生成自动一个key if (StringUtils.isEmpty(key)) { Class[] type = method.getParameterTypes(); key = method.getClass() + method.getName(); if (type != null) { String paramTypes = Arrays.stream(type) .map(Class::getName) .collect(Collectors.joining(",")); log.info("param types: " + paramTypes); key += "#" + paramTypes; } } // 2. 调用Redis boolean acquired = stringRedisTemplate.execute( rateLimitLua, // Lua script的真身 Lists.newArrayList(key), // Lua脚本中的Key列表 limit.toString() // Lua脚本Value列表 ); if (!acquired) { log.error("your access is blocked, key={}", key); throw new RuntimeException("Your access is blocked"); } } } ``` 重新打包 1. ratelimiter-annotation 项目打包 mvn clean package 1. IDEA File --> Project Structure --> Libranies + --> Java (ratelimiter-annotation-1.0-SNAPSHOT.jar) **ratelimiter-test** ```java /** * @author eddie.lee * @ProjectName ratelimiter-test * @Package com.example.springcloud * @ClassName Controller * @description * @date created in 2020-12-25 9:02 * @modified by */ @Slf4j @RestController public class Controller { @Autowired private AccessLimiter accessLimiter; @GetMapping("test") public String test() { accessLimiter.limitAccess("ratelimiter-test", 1); return "success"; } // 提醒！注意配置扫包 (com.example.springcloud路径不同) @GetMapping("test-annotation") @com.example.springcloud.annotation.AccessLimiter(limit = 1, methodKey = "ratelimiter-test") public String testAnnotation() { return "success"; } } ``` 测试效果和基础版一样 </details>

基于Nginx的分布式限流

分布式锁-进阶