Resilience4j_服务端限流、并发控制_RateLimiter

小鱼儿 2021-10-15 00:17 504阅读 0赞

## 一、背景描述 ##

由于Hystrix官方已经停止更新，Spring 官网推荐使用Resilience4j作为服务的熔断保护中间件，可见Resilience4j的重要性。  
为了探究Resilience4j实现服务熔断功能， 我们选用了 consul 作为注册中心，启动了一个服务端（waiter）,验证其服务端限流、并发控制熔断。我们在极端的时间内访问较多次数指定接口，观察接口是否会进行熔断处理。 consul 启动及运行状态监控，不在这里描述， 我们默认 consul 已经正常运行。  
本地安装运行consul 参考：[https://jingyan.baidu.com/article/ca41422f732f961eaf99ed5f.html][https_jingyan.baidu.com_article_ca41422f732f961eaf99ed5f.html]  
在RateLimiter中有两种使用方式：基于注解，或熔断对象注入两种方式，下面会分别进行演示。

## 二、代码演示 ##

**2.1 pom主要依赖**

<properties>
    		<java.version>1.8</java.version>
    		<spring-cloud.version>Greenwich.SR1</spring-cloud.version>
    </properties>
    	
    <dependencyManagement>
    		<dependencies>
    			<dependency>
    				<groupId>org.springframework.cloud</groupId>
    				<artifactId>spring-cloud-dependencies</artifactId>
    				<version>${spring-cloud.version}</version>
    				<type>pom</type>
    				<scope>import</scope>
    			</dependency>
    		</dependencies>
    </dependencyManagement>
    
        	<dependency>
     			<groupId>org.springframework.boot</groupId>
    			<artifactId>spring-boot-starter-web</artifactId>
    		</dependency>
    		<dependency>
    			<groupId>org.springframework.boot</groupId>
    			<artifactId>spring-boot-starter-actuator</artifactId>
    		</dependency>
    		
    		<dependency>
    			<groupId>org.springframework.cloud</groupId>
    			<artifactId>spring-cloud-starter-consul-discovery</artifactId>
    		</dependency>
    		
    		<dependency>
    			<groupId>io.github.resilience4j</groupId>
    			<artifactId>resilience4j-spring-boot2</artifactId>
    			<version>0.14.1</version>
    		</dependency>

**2.2 配置文件**

application.properties

#0表示服务器随机端口
    server.port=0
    #consul  地址
    spring.cloud.consul.host=localhost
    #consul  端口
    spring.cloud.consul.port=8500
    spring.cloud.consul.discovery.prefer-ip-address=true
    #限流熔断组annotation策略设置如下：
    #限制连续请求5次
    resilience4j.ratelimiter.limiters.annotation.limit-for-period=5
    #30s刷新统计值
    resilience4j.ratelimiter.limiters.annotation.limit-refresh-period-in-millis=30000
    #5s超时
    resilience4j.ratelimiter.limiters.annotation.timeout-in-millis=5000
    #actuator 订阅endpoint
    resilience4j.ratelimiter.limiters.annotation.subscribe-for-events=true
    #Metrics endpoint监控指标
    resilience4j.ratelimiter.limiters.annotation.register-health-indicator=true
    
    #限流熔断组registry策略设置如下：
    #限制连续请求3次
    resilience4j.ratelimiter.limiters.registry.limit-for-period=3
    #30s刷新统计值
    resilience4j.ratelimiter.limiters.registry.limit-refresh-period-in-millis=30000
    #5s超时
    resilience4j.ratelimiter.limiters.registry.timeout-in-millis=1000
    #actuator 订阅endpoint
    resilience4j.ratelimiter.limiters.registry.subscribe-for-events=true
    #Metrics endpoint监控指标
    resilience4j.ratelimiter.limiters.registry.register-health-indicator=true

bootstrap.properties

#服务名称
    spring.application.name=waiter-service

**2.3 代码**  
1）AnnotationController 基于注解实现

@RestController
    @RequestMapping("/annotation")
    @Slf4j
    @RateLimiter(name = "annotation")
    public class AnnotationController {
    
        @PostMapping("/value")
        public  Object  gotoValue(){
            String result = "hello ! this is return annotation ratelimiter";
            return  result ;
        }

2）RegistryController 基于注入类方式实现

@RestController
    @RequestMapping("registry")
    @Slf4j
    public class RegistryController {
        private RateLimiter rateLimiter;
    
        public RegistryController(RateLimiterRegistry rateLimiterRegistry) {
            rateLimiter = rateLimiterRegistry.rateLimiter("registry");
        }
    
        @RequestMapping("/resut")
        public  Object  gotoRegistry(HttpServletRequest request){
            String resut = null;
            try {
                resut = rateLimiter.executeSupplier(() -> "hello ! this is return registry ratelimiter ! haha! ");
            } catch(RequestNotPermitted e) {
                log.warn("Request Not Permitted! {}", e.getMessage());
            }
            return resut;
        }
    }

## 三、熔断结果演示 ##

1.  基于注解熔断情况  
    接口：[http://localhost:8080/annotation/value][http_localhost_8080_annotation_value]  
    步骤：连续请接口5次

正常返回  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2OTE4MTQ5_size_16_color_FFFFFF_t_70]  
返回报错  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2OTE4MTQ5_size_16_color_FFFFFF_t_70 1]  
后端报错  
![在这里插入图片描述][20190815000317144.png]

1.  基于注册熔断器方式熔断情况  
    接口：[http://localhost:8080/registry/resut][http_localhost_8080_registry_resut]  
    步骤：连续请接口3次  
    正常返回  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2OTE4MTQ5_size_16_color_FFFFFF_t_70 2]  
    返回报错（空）  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2OTE4MTQ5_size_16_color_FFFFFF_t_70 3]  
    后端报错  
    ![在这里插入图片描述][20190815000712407.png]
2.  熔断监控  
    可以通过actuator 查看当前服务熔断情况  
    请求熔断情况： [http://localhost:8080/actuator/ratelimiters][http_localhost_8080_actuator_ratelimiters]  
    有哪些熔断器策略：[http://localhost:8080/actuator/ratelimiters][http_localhost_8080_actuator_ratelimiters]

[https_jingyan.baidu.com_article_ca41422f732f961eaf99ed5f.html]: https://jingyan.baidu.com/article/ca41422f732f961eaf99ed5f.html
[http_localhost_8080_annotation_value]: http://localhost:8080/annotation/value
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2OTE4MTQ5_size_16_color_FFFFFF_t_70]: /images/20211015/ee580354cf1f4a3e9d5e81261089783f.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2OTE4MTQ5_size_16_color_FFFFFF_t_70 1]: /images/20211015/9ee63a869fe745b6ba8287a26c5ad1c6.png
[20190815000317144.png]: /images/20211015/c5bd3486efe0451cadab2a00e0a30b2c.png
[http_localhost_8080_registry_resut]: http://localhost:8080/registry/resut
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2OTE4MTQ5_size_16_color_FFFFFF_t_70 2]: /images/20211015/142064e783be4170afc4756c75a46dfd.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2OTE4MTQ5_size_16_color_FFFFFF_t_70 3]: /images/20211015/496422f4428847799ed046fb0fc35878.png
[20190815000712407.png]: /images/20211015/9119f37ab7644ef3a364bdd7a6a5702b.png
[http_localhost_8080_actuator_ratelimiters]: http://localhost:8080/actuator/ratelimiters