resilience4j + CircuitBreaker

Author: YunaiV

lab-59/lab-59-resilience4j-demo01/pom.xml

@@ -0,0 +1,60 @@
+<?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">
+    <parent>
+        <artifactId>lab-59</artifactId>
+        <groupId>cn.iocoder.springboot.labs</groupId>
+        <version>1.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>lab-59-resilience4j-demo01</artifactId>
+
+    <properties>
+        <maven.compiler.target>1.8</maven.compiler.target>
+        <maven.compiler.source>1.8</maven.compiler.source>
+        <spring.boot.version>2.2.4.RELEASE</spring.boot.version>
+    </properties>
+
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-starter-parent</artifactId>
+                <version>${spring.boot.version}</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+
+    <dependencies>
+        <!-- 引入 SpringMVC 相关依赖，并实现对其的自动配置 -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+
+        <!-- 引入 Resilience4j Starter 相关依赖，并实现对其的自动配置 -->
+        <dependency>
+            <groupId>io.github.resilience4j</groupId>
+            <artifactId>resilience4j-spring-boot2</artifactId>
+            <version>1.4.0</version>
+        </dependency>
+
+        <!-- 引入 Aspectj 依赖，支持 AOP 相关注解、表达式等等 -->
+        <dependency>
+            <groupId>org.aspectj</groupId>
+            <artifactId>aspectjrt</artifactId>
+            <version>1.9.5</version>
+        </dependency>
+        <dependency>
+            <groupId>org.aspectj</groupId>
+            <artifactId>aspectjweaver</artifactId>
+            <version>1.9.5</version>
+        </dependency>
+
+    </dependencies>
+
+</project>

lab-59/lab-59-resilience4j-demo01/src/main/java/cn/iocoder/springboot/lab59/resillience4jdemo/DemoApplication.java

@@ -0,0 +1,20 @@
+package cn.iocoder.springboot.lab59.resillience4jdemo;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+import org.springframework.web.client.RestTemplate;
+
+@SpringBootApplication
+public class DemoApplication {
+
+    @Bean
+    public RestTemplate restTemplate() {
+        return new RestTemplate();
+    }
+
+    public static void main(String[] args) {
+        SpringApplication.run(DemoApplication.class, args);
+    }
+
+}

lab-59/lab-59-resilience4j-demo01/src/main/java/cn/iocoder/springboot/lab59/resillience4jdemo/controller/DemoController.java

@@ -0,0 +1,34 @@
+package cn.iocoder.springboot.lab59.resillience4jdemo.controller;
+
+import io.github.resilience4j.circuitbreaker.annotation.CircuitBreaker;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.client.RestTemplate;
+
+@RestController
+@RequestMapping("/demo")
+public class DemoController {
+
+    private Logger logger = LoggerFactory.getLogger(getClass());
+
+    @Autowired
+    private RestTemplate restTemplate;
+
+    @GetMapping("/get_user")
+    @CircuitBreaker(name = "backendA", fallbackMethod = "getUserFallback")
+    public String getUser(@RequestParam("id") Integer id) {
+        logger.info("[getUser][准备调用 user-service 获取用户({})详情]", id);
+        return restTemplate.getForEntity("http://127.0.0.1:18080/user/get?id=" + id, String.class).getBody();
+    }
+
+    public String getUserFallback(Integer id, Throwable throwable) {
+        logger.info("[getUserFallback][id({}) exception({})]", id, throwable.getClass().getSimpleName());
+        return "mock:User:" + id;
+    }
+
+}

lab-59/lab-59-resilience4j-demo01/src/main/resources/application.yml

@@ -0,0 +1,11 @@
+resilience4j:
+  # Resilience4j 的断路器配置项，对应 CircuitBreakerProperties 属性类
+  circuitbreaker:
+    instances:
+      backendA:
+        ring-buffer-size-in-closed-state: 5 # 熔断器关闭状态的缓冲区大小，不会限制线程的并发量，在熔断器发生状态转换前所有请求都会调用后端服务。
+        ring-buffer-size-in-half-open-state: 5 # 熔断器半开状态的缓冲区大小，会限制线程的并发量。例如，缓冲区为 10 则每次只会允许 10 个请求调用后端服务。
+        wait-duration-in-open-state : 5000 # 熔断器从打开状态转变为半开状态等待的时间，单位：毫秒
+        failure-rate-threshold: 50 # 熔断器关闭状态和半开状态使用的同一个失败率阈值，单位：百分比
+
+        register-health-indicator: true # 是否注册到健康监测

lab-59/pom.xml

@@ -14,6 +14,7 @@
 
     <modules>
         <module>lab-59-user-service</module>
+        <module>lab-59-resilience4j-demo01</module>
     </modules>
 
 </project>