我是 Resilience4j 和断路器模式的新手。
我为resilience4j 编写了一个示例。详情如下:
pom.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 https://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>2.3.2.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>ir.co.isc</groupId>
<artifactId>circuit-breaker</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>circuit-breaker</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>11</java.version>
<spring-cloud.version>Hoxton.SR6</spring-cloud.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!-- resilience4j dependency-->
<dependency>
<groupId>io.github.resilience4j</groupId>
<artifactId>resilience4j-spring-boot2</artifactId>
<version>1.5.0</version>
<type>pom</type>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-aop</artifactId>
<version>2.3.0.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
<version>2.3.2.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
<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>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
应用程序.yml:
resilience4j:
circuitbreaker:
configs:
default:
registerHealthIndicator: true
slidingWindowSize: 10
minimumNumberOfCalls: 5
permittedNumberOfCallsInHalfOpenState: 3
automaticTransitionFromOpenToHalfOpenEnabled: true
waitDurationInOpenState: 5s
failureRateThreshold: 20
eventConsumerBufferSize: 10
instances:
mainService:
baseConfig: default
控制器类:
package ir.co.isc.circuitbreaker;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class MainServiceController {
@Autowired
private MainService mainService;
@GetMapping("/getSleuthTest")
@ResponseStatus(HttpStatus.OK)
public ResponseEntity<String> getSleuthTest(){
String response = mainService.getResponse();
return new ResponseEntity<>(response, HttpStatus.OK);
}
}
服务等级:
package ir.co.isc.circuitbreaker;
import io.github.resilience4j.circuitbreaker.annotation.CircuitBreaker;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;
@Service
public class MainService {
private static final String MAIN_SERVICE = "mainService";
@Autowired
private RestTemplate restTemplate;
@Bean
public RestTemplate getRestTemplate() {
return new RestTemplate();
}
@CircuitBreaker(name = MAIN_SERVICE, fallbackMethod="testFallBack")
public String getResponse(){
return restTemplate.getForObject("http://localhost:8081/serviceOne", String.class);
}
private ResponseEntity<String> testFallBack(Exception e){
return new ResponseEntity<>("In fallback method", HttpStatus.INTERNAL_SERVER_ERROR);
}
}
SpringBootApplication 类:
package ir.co.isc.circuitbreaker;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class CircuitBreakerApplication {
public static void main(String[] args) {
SpringApplication.run(CircuitBreakerApplication.class, args);
}
}
我使用 postman runner 来调用我的 API。我将运行器迭代设置为 200。在 10 次成功的 API 调用后,我在此 url 中停止第三方:http://localhost:8081/serviceOne
据我了解,停止第三方API并记录成功调用的最小次数后,resilience4j开始计算故障率,当故障率大于failureRateThreshold时,调用回退方法(这里是服务类中的testFallBack),电路状态从关闭变为打开模式并返回在 testFallBack() 方法中描述的我想要的答案。
但这永远不会发生(从未调用过 testFallBack() 方法)。我的申请有什么问题?