Sentinel4服务熔断

1.Sentinel服务熔断Ribbon环境预说

sentinel整合ribbon+openFeign+fallback
Ribbon系列

  • 启动nacos和sentinel
  • 提供者9003/9004
  • 消费者84

提供者9003/9004
新建cloudalibaba-provider-payment9003/9004，两个一样的做法
POM

  1.  <dependencies>
  2.         <!--SpringCloud ailibaba nacos -->
  3.         <dependency>
  4.             <groupId>com.alibaba.cloud</groupId>
  5.             <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
  6.         </dependency>
  8.         <!-- SpringBoot整合Web组件 -->
  9.         <dependency>
  10.             <groupId>org.springframework.boot</groupId>
  11.             <artifactId>spring-boot-starter-web</artifactId>
  12.         </dependency>
  13.         <dependency>
  14.             <groupId>org.springframework.boot</groupId>
  15.             <artifactId>spring-boot-starter-actuator</artifactId>
  16.         </dependency>
  17.         <!--日常通用jar包配置-->
  18.         <dependency>
  19.             <groupId>org.springframework.boot</groupId>
  20.             <artifactId>spring-boot-devtools</artifactId>
  21.             <scope>runtime</scope>
  22.             <optional>true</optional>
  23.         </dependency>
  24.         <dependency>
  25.             <groupId>org.projectlombok</groupId>
  26.             <artifactId>lombok</artifactId>
  27.             <optional>true</optional>
  28.         </dependency>
  29.         <dependency>
  30.             <groupId>org.springframework.boot</groupId>
  31.             <artifactId>spring-boot-starter-test</artifactId>
  32.             <scope>test</scope>
  33.         </dependency>
  34.     </dependencies>

YML 

  1. server:
  2.   port: 9003
  4. spring:
  5.   application:
  6.     name: zds-egg-provider-payment9003
  7.   cloud:
  8.     nacos:
  9.       discovery:
  10.         server-addr: 127.0.0.1:8848 #配置Nacos地址
  12. management:
  13.   endpoints:
  14.     web:
  15.       exposure:
  16.         include: '*'

主启动 

  1. import org.springframework.boot.SpringApplication;
  2. import org.springframework.boot.autoconfigure.SpringBootApplication;
  3. import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
  5. @SpringBootApplication
  6. @EnableDiscoveryClient
  7. public class PaymentMain9003 {
  8.     public static void main(String[] args) {
  9.         SpringApplication.run(PaymentMain9003.class, args);
  10.     }
  11. }

业务类 

  1. @RestController
  2. public class PaymentController {
  3.     @Value("${server.port}")
  4.     private String serverPort;
  6.     @GetMapping(value = "/paymentSQL/{id}")
  7.     public SingleResult paymentSQL(@PathVariable("id") Long id){
  8.         SingleResult singleResult = new SingleResult();
  9.         singleResult.success("","from mysql,serverPort:  "+serverPort);
  10.         return singleResult;
  11.     }
  13. }

测试地址 - http://localhost:9003/paymentSQL/1

消费者84
新建zds-egg-consumer-order84
pom

  1. <dependencies>
  2.         <!--SpringCloud openfeign -->
  3.       <!--  <dependency>
  4.             <groupId>org.springframework.cloud</groupId>
  5.             <artifactId>spring-cloud-starter-openfeign</artifactId>
  6.         </dependency>-->
  7.         <!--SpringCloud ailibaba nacos -->
  8.         <dependency>
  9.             <groupId>com.alibaba.cloud</groupId>
  10.             <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
  11.         </dependency>
  12.         <!--SpringCloud ailibaba sentinel -->
  13.         <dependency>
  14.             <groupId>com.alibaba.cloud</groupId>
  15.             <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
  16.         </dependency>
  17.         <!-- SpringBoot整合Web组件 -->
  18.         <dependency>
  19.             <groupId>org.springframework.boot</groupId>
  20.             <artifactId>spring-boot-starter-web</artifactId>
  21.         </dependency>
  22.         <dependency>
  23.             <groupId>org.springframework.boot</groupId>
  24.             <artifactId>spring-boot-starter-actuator</artifactId>
  25.         </dependency>
  26.         <!--日常通用jar包配置-->
  27.         <dependency>
  28.             <groupId>org.springframework.boot</groupId>
  29.             <artifactId>spring-boot-devtools</artifactId>
  30.             <scope>runtime</scope>
  31.             <optional>true</optional>
  32.         </dependency>
  33.         <dependency>
  34.             <groupId>org.projectlombok</groupId>
  35.             <artifactId>lombok</artifactId>
  36.             <optional>true</optional>
  37.         </dependency>
  38.         <dependency>
  39.             <groupId>org.springframework.boot</groupId>
  40.             <artifactId>spring-boot-starter-test</artifactId>
  41.             <scope>test</scope>
  42.         </dependency>
  43.         <dependency>
  44.             <groupId>org.springframework.cloud</groupId>
  45.             <artifactId>spring-cloud-openfeign-core</artifactId>
  46.         </dependency>
  47.     </dependencies>

YML 

  1. server:
  2.   port: 84
  4. spring:
  5.   application:
  6.     name: nacos-order-consumer
  7.   cloud:
  8.     nacos:
  9.       discovery:
  10.         server-addr: localhost:8848
  11.     sentinel:
  12.       transport:
  13.         #配置Sentinel dashboard地址
  14.         dashboard: localhost:8080
  15.         #默认8719端口，假如被占用会自动从8719开始依次+1扫描,直至找到未被占用的端口
  16.         port: 8719
  18. #消费者将要去访问的微服务名称(注册成功进nacos的微服务提供者)
  19. service-url:
  20.   nacos-user-service: http://zds-egg-provider-payment
  22. # 激活Sentinel对Feign的支持
  23. feign:
  24.   sentinel:
  25.     enabled: false

主启动

  1. @EnableDiscoveryClient
  2. @SpringBootApplication
  3. @EnableFeignClients
  4. public class OrderNacosMain84 {
  5.     public static void main(String[] args) {
  6.         SpringApplication.run(OrderNacosMain84.class, args);
  7.     }
  8. }

ApplicationContextConfig

  1. @Configuration
  2. public class ApplicationContextConfig {
  4.     @Bean
  5.     @LoadBalanced
  6.     public RestTemplate getRestTemplate() {
  7.         return new RestTemplate();
  8.     }
  9. }

CircleBreakerController

  1. @RestController
  2. @Slf4j
  3. public class CircleBreakerController {
  4.     public static final String SERVICE_URL = "http://zds-egg-provider-payment";
  6.     @Resource
  7.     private RestTemplate restTemplate;
  9.     @RequestMapping("/consumer/fallback/{id}")
  10.     @SentinelResource(value = "fallback")//没有配置
  11.     public SingleResult fallback(@PathVariable Long id) {
  12.         SingleResult result = restTemplate.getForObject(SERVICE_URL + "/paymentSQL/" + id, SingleResult.class, id);
  14.         if (id == 4) {
  15.             throw new IllegalArgumentException("IllegalArgumentException,非法参数异常....");
  16.         } else if (result.getData() == null) {
  17.             throw new NullPointerException("NullPointerException,该ID没有对应记录,空指针异常");
  18.         }
  20.         return result;
  21.     }
  22. }

测试地址 - http://localhost:84/consumer/fallback/1

2.Sentinel服务熔断无配置

3.Sentinel服务熔断只配置fallback

4.Sentinel服务熔断只配置blockHandler

5. Sentinel服务熔断fallback和blockHandler都配置

6.Sentinel服务熔断exceptionsToIgnore

7.Sentinel服务熔断OpenFeign

修改84模块

  • 84消费者调用提供者9003
  • Feign组件一般是消费侧

pom

  1. <!--SpringCloud openfeign -->
  3. <dependency>
  4.     <groupId>org.springframework.cloud</groupId>
  5.     <artifactId>spring-cloud-starter-openfeign</artifactId>
  6. </dependency>

yml

  1. # 激活Sentinel对Feign的支持
  2. feign:
  3.   sentinel:
  4.     enabled: true

业务类
带@Feignclient注解的业务接口，fallback = PaymentFallbackService.class

  1. @FeignClient(value = "zds-egg-provider-payment",fallback = PaymentFallbackService.class)
  2. public interface PaymentService {
  4.     @GetMapping(value = "/paymentSQL/{id}")
  5.     public SingleResult paymentSQL(@PathVariable("id") Long id);
  8. }
  1. @Component
  2. public class PaymentFallbackService implements PaymentService{
  4.     @Override
  5.     public SingleResult paymentSQL(Long id) {
  6.         return new SingleResult().except(44444,"服务降级返回,---PaymentFallbackService","","");
  7.     }
  9. }

Controller

  1.     //==================OpenFeign
  2.     @Resource
  3.     private PaymentService paymentService;
  5.     @GetMapping(value = "/consumer/paymentSQL/{id}")
  6.     public SingleResult paymentSQL(@PathVariable("id") Long id) {
  7.         return paymentService.paymentSQL(id);
  8.     }

启动类

  1. @EnableDiscoveryClient
  2. @SpringBootApplication
  3. @EnableFeignClients//<--------------
  4. public class OrderNacosMain84 {
  5.     public static void main(String[] args) {
  6.         SpringApplication.run(OrderNacosMain84.class, args);
  7.     }
  8. }

测试 - http://localhost:84/consumer/paymentSQL/1
测试84调用9003，此时故意关闭9003微服务提供者，84消费侧自动降级，不会被耗死。
熔断框架比较

| - | Sentinel | Hystrix | resilience4j | | —- | —- | —- | —- |

| 隔离策略 | 信号量隔离（并发线程数限流） | 线程池隔商/信号量隔离 | 信号量隔离 |

| 熔断降级策略 | 基于响应时间、异常比率、异常数 | 基于异常比率 | 基于异常比率、响应时间 |

| 实时统计实现 | 滑动窗口（LeapArray） | 滑动窗口（基于RxJava） | Ring Bit Buffer |

| 动态规则配置 | 支持多种数据源 | 支持多种数据源 | 有限支持 |

| 扩展性 | 多个扩展点 | 插件的形式 | 接口的形式 |

| 基于注解的支持 | 支持 | 支持 | 支持 |

| 限流 | 基于QPS，支持基于调用关系的限流 | 有限的支持 | Rate Limiter |

| 流量整形 | 支持预热模式匀速器模式、预热排队模式 | 不支持 | 简单的Rate Limiter模式 |

| 系统自适应保护 | 支持 | 不支持 | 不支持 |

| 控制台 | 提供开箱即用的控制台，可配置规则、查看秒级监控，机器发观等 | 简单的监控查看 | 不提供控制台，可对接其它监控系统 |

8.Sentinel持久化规则

是什么
一旦我们重启应用，sentinel规则将消失，生产环境需要将配置规则进行持久化。
怎么玩
将限流配置规则持久化进Nacos保存，只要刷新8401某个rest地址，sentinel控制台的流控规则就能看到，只要Nacos里面的配置不删除，针对8401上sentinel上的流控规则持续有效。
步骤
修改zds-egg-sentinel8401
POM 

  1. <!--SpringCloud ailibaba sentinel-datasource-nacos 后续做持久化用到-->
  2. <dependency>
  3.     <groupId>com.alibaba.csp</groupId>
  4.     <artifactId>sentinel-datasource-nacos</artifactId>
  5. </dependency>

YML

  2. server:
  3.   port: 8401
  5. spring:
  6.   application:
  7.     name: zds-egg-sentinel-service
  8.   cloud:
  9.     nacos:
  10.       discovery:
  11.         namespace: bcba2f23-08ae-45e7-9ef0-f659cdf60ceb
  12.         group: DEFAULT_GROUP
  13.         server-addr: 127.0.0.1:8848 #Nacos服务注册中心地址
  14.     sentinel:
  15.       transport:
  16.         dashboard: 127.0.0.1:8080 #配置Sentinel dashboard地址
  17.         port: 8719
  18.       # Sentinel默认会将Controller方法做context整合，导致链路模式的流控失效
  19. #      web-context-unify: false
  20.       datasource: #<---------------------------关注点，添加Nacos数据源配置
  21.         ds1: # 这里的flow名字随便取   流控规则
  22.           nacos:
  23.             namespace: bcba2f23-08ae-45e7-9ef0-f659cdf60ceb
  24.             server-addr: 127.0.0.1:8848
  25.             dataId: zds-egg-sentinel-service
  26.             groupId: SENTINEL_GROUP
  27.             data-type: json
  28.             rule-type: flow
  29. #暴露自己的端点
  30. management:
  31.   endpoints:
  32.     web:
  33.       exposure:
  34.         include: '*'
  36. feign:
  37.   sentinel:
  38.     enabled: true # 激活Sentinel对Feign的支持

添加Nacos业务规则配置

配置内容解析

  1. [{
  2.     "resource": "/rateLimit/byUrl",
  3.     "IimitApp": "default",
  4.     "grade": 1,
  5.     "count": 1, 
  6.     "strategy": 0,
  7.     "controlBehavior": 0,
  8.     "clusterMode": false
  9. }]
  • resource：资源名称；
  • limitApp：来源应用；
  • grade：阈值类型，0表示线程数, 1表示QPS；
  • count：单机阈值；
  • strategy：流控模式，0表示直接，1表示关联，2表示链路；
  • controlBehavior：流控效果，0表示快速失败，1表示Warm Up，2表示排队等待；
  • clusterMode：是否集群。

启动8401后刷新sentinel发现业务规则有了

快速访问测试接口 - http://localhost:8401/rateLimit/byUrl - 页面返回Blocked by Sentinel (flow limiting)
停止8401再看sentinel - 停机后发现流控规则没有了
新启动8401再看sentinel