✨ 负载均衡使用

2025-05-26 13:32:07 +08:00 · 2025-05-26 13:32:07 +08:00 · f12f1a6ed3
parent 3e61995bc6
commit f12f1a6ed3
6 changed files with 137 additions and 48 deletions
--- a/cloud-demo/ReadMe.md
+++ b/cloud-demo/ReadMe.md
@ -28,12 +28,12 @@ sudo systemctl daemon-reload && sudo systemctl restart docker

 #### MySQL配置问题

-| **特性**     | `**my.cnf**`                 | `**conf.d**` **目录**      |
-| ------------ | ---------------------------- | -------------------------- |
-| **文件类型** | 单个文件                     | 目录，包含多个 `.cnf` 文件 |
-| **配置方式** | 集中式配置                   | 分布式配置                 |
-| **优先级**   | 高（覆盖 `conf.d` 中的配置） | 低（被 `my.cnf` 覆盖）     |
-| **适用场景** | 全局配置，核心配置           | 模块化配置，便于扩展和维护 |
+| **特性**   | `**my.cnf**`        | `**conf.d**` **目录** |
+|----------|:--------------------|:-------------------:|
+| **文件类型** | 单个文件                |  目录，包含多个 `.cnf` 文件  |
+| **配置方式** | 集中式配置               |        分布式配置        |
+| **优先级**  | 高（覆盖 `conf.d` 中的配置） |  低（被 `my.cnf` 覆盖）   |
+| **适用场景** | 全局配置，核心配置           |    模块化配置，便于扩展和维护    |

 #### MongoDB配置

@ -95,16 +95,16 @@ db.createUser({ user: 'admin', pwd: '02120212', roles: [ { role: "root", db: "ad

 如果休要所有的微服务环境，可以直接复制下面的内容，看清楚目录是否和自己需要的一样。

-| 功能                 | 旧版 (docker-compose)   | 新版 (docker  compose)  |
-| -------------------- | ----------------------- | ----------------------- |
-| **启动服务**         | docker-compose  up -d   | docker  compose up -d   |
-| **停止服务**         | docker-compose  down    | docker  compose down    |
-| **查看日志**         | docker-compose  logs -f | docker  compose logs -f |
-| **列出容器**         | docker-compose  ps      | docker  compose ps      |
-| **停止不删除容器**   | docker-compose  stop    | docker  compose stop    |
+| 功能           | 旧版 (docker-compose)     | 新版 (docker  compose)    |
+|--------------|-------------------------|-------------------------|
+| **启动服务**     | docker-compose  up -d   | docker  compose up -d   |
+| **停止服务**     | docker-compose  down    | docker  compose down    |
+| **查看日志**     | docker-compose  logs -f | docker  compose logs -f |
+| **列出容器**     | docker-compose  ps      | docker  compose ps      |
+| **停止不删除容器**  | docker-compose  stop    | docker  compose stop    |
 | **启动已停止的容器** | docker-compose  start   | docker  compose start   |
-| **重启服务**         | docker-compose  restart | docker  compose restart |
-| **构建镜像**         | docker-compose  build   | docker  compose build   |
+| **重启服务**     | docker-compose  restart | docker  compose restart |
+| **构建镜像**     | docker-compose  build   | docker  compose build   |

 ```yaml
 name: cloud-services
@ -131,8 +131,8 @@ services:
    restart: always
    privileged: true
    networks:
-      - cloud  
- 
+      - cloud
+
  redis:
    container_name: redis_master
    image: redis:7.0.10
@ -149,8 +149,8 @@ services:
      - "--tcp-keepalive 300"
    restart: always
    networks:
-      - cloud  
- 
+      - cloud
+
  minio:
    image: minio/minio
    container_name: minio_master
@ -165,7 +165,7 @@ services:
    command: "server /data --console-address :9090"
    restart: always
    networks:
-      - cloud  
+      - cloud

  mongodb:
    image: mongo:latest
@ -180,8 +180,8 @@ services:
      - ~/docker/docker_data/mongo/logs:/data/log
    command: "mongod --config /data/configdb/mongod.conf"
    networks:
-      - cloud  
-  
+      - cloud
+
  rabbitmq:
    image: rabbitmq:management
    container_name: rabbitmq
@ -199,7 +199,7 @@ services:
      - RABBITMQ_DEFAULT_VHOST=/
    networks:
      - cloud
-      
+
  nacos:
    image: nacos/nacos-server:v2.4.3
    container_name: nacos
@ -210,8 +210,8 @@ services:
      - MODE=standalone
    restart: always
    networks:
-      - cloud  
- 
+      - cloud
+
  sentinel:
    image: bladex/sentinel-dashboard:1.8.8
    container_name: sentinel
@ -220,7 +220,7 @@ services:
    privileged: true
    restart: always
    networks:
-      - cloud  
+      - cloud

  seata-server:
    image: apache/seata-server:2.3.0.jdk21
@ -229,7 +229,7 @@ services:
      - "8091:8091"
    restart: always
    networks:
-      - cloud  
+      - cloud

 networks: # 定义网络
  cloud: # 定义名为 auth 的网络
@ -244,24 +244,81 @@ networks: # 定义网络
 发现服务信息。

 ```java
-for (String service : discoveryClient.getServices()) {
-    System.out.println(service);
+@SpringBootTest()
+public class DiscoveryTest {

-    for (ServiceInstance instance : discoveryClient.getInstances(service)) {
-        System.out.println("IP地址：" + instance.getHost());
-        System.out.println("端口号" + instance.getPort());
-    }
-}
+    @Autowired
+    private DiscoveryClient discoveryClient;

-System.out.println("----------------------------------------------");
+    @Autowired
+    private NacosDiscoveryClient nacosDiscoveryClient;

-// 两个方式一样，DiscoveryClient 是 Spring自带的 NacosDiscoveryClient是 Nacos
-for (String service : nacosDiscoveryClient.getServices()) {
-    System.out.println(service);
+    @Test
+    void discoveryClientTest() {
+        for (String service : discoveryClient.getServices()) {
+            System.out.println(service);

-    for (ServiceInstance instance : nacosDiscoveryClient.getInstances(service)) {
-        System.out.println("IP地址：" + instance.getHost());
-        System.out.println("端口号" + instance.getPort());
+            for (ServiceInstance instance : discoveryClient.getInstances(service)) {
+                System.out.println("IP地址：" + instance.getHost());
+                System.out.println("端口号" + instance.getPort());
+            }
+        }
+
+        System.out.println("----------------------------------------------");
+
+        // 两个方式一样，DiscoveryClient 是 Spring自带的 NacosDiscoveryClient是 Nacos
+        for (String service : nacosDiscoveryClient.getServices()) {
+            System.out.println(service);
+
+            for (ServiceInstance instance : nacosDiscoveryClient.getInstances(service)) {
+                System.out.println("IP地址：" + instance.getHost());
+                System.out.println("端口号" + instance.getPort());
+            }
+        }
    }
 }
 ```
+
+### 远程调用
+
+订单模块调用远程商品模块，使用了nacos，可以使用`RestTemplate`，其中`RestTemplate`是线程安全的，只要注册一次全局都是可以使用。
+
+**RestTemplate源码**
+
+继承了`InterceptingHttpAccessor`，在`InterceptingHttpAccessor`中，使用了单例模式。
+
+```java
+public ClientHttpRequestFactory getRequestFactory() {
+    List<ClientHttpRequestInterceptor> interceptors = this.getInterceptors();
+    if (!CollectionUtils.isEmpty(interceptors)) {
+        ClientHttpRequestFactory factory = this.interceptingRequestFactory;
+        if (factory == null) {
+            factory = new InterceptingClientHttpRequestFactory(super.getRequestFactory(), interceptors);
+            this.interceptingRequestFactory = factory;
+        }
+
+        return factory;
+    } else {
+        return super.getRequestFactory();
+    }
+}
+```
+
+**实现远程调用**
+
+如果我们的服务启动了多个，在下面代码中即使一个服务宕机也可以做到远程调用。
+
+```java
+private Product getProductFromRemote(Long productId) {
+    // 获取商品服务所有及其的 IP+port
+    List<ServiceInstance> instances = discoveryClient.getInstances("service-product");
+    ServiceInstance instance = instances.get(0);
+
+    // 远程URL
+    String url = "http://" + instance.getHost() + ":" + instance.getPort() + "/api/product/" + productId;
+
+    // 2. 远程发送请求
+    log.info("远程调用：{}", url);
+    return restTemplate.getForObject(url, Product.class);
+}
+```
--- a/cloud-demo/services/pom.xml
+++ b/cloud-demo/services/pom.xml
@ -68,6 +68,10 @@
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
+        <dependency>
+            <groupId>org.springframework.cloud</groupId>
+            <artifactId>spring-cloud-starter-loadbalancer</artifactId>
+        </dependency>

        <!-- knife4j -->
        <dependency>
--- a/cloud-demo/services/service-order/src/main/java/cn/bunny/service/service/impl/OrderServiceImpl.java
+++ b/cloud-demo/services/service-order/src/main/java/cn/bunny/service/service/impl/OrderServiceImpl.java
@ -7,6 +7,7 @@ import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.cloud.client.ServiceInstance;
 import org.springframework.cloud.client.discovery.DiscoveryClient;
+import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
 import org.springframework.stereotype.Service;
 import org.springframework.web.client.RestTemplate;

@ -20,6 +21,7 @@ public class OrderServiceImpl implements OrderService {

    private final DiscoveryClient discoveryClient;
    private final RestTemplate restTemplate;
+    private final LoadBalancerClient loadBalancerClient;

    /**
     * 创建订单信息
@ -30,7 +32,7 @@ public class OrderServiceImpl implements OrderService {
     */
    @Override
    public Order createOrder(Long productId, Long userId) {
-        Product product = getProductFromRemote(productId);
+        Product product = getProductFromRemoteWithLoadBalancer(productId);

        Order order = new Order();
        order.setId(1L);
@ -40,13 +42,19 @@ public class OrderServiceImpl implements OrderService {
        order.setNickName("在资质");
        order.setAddress("地址地址。。。");

-        // TODO 远程查询
+        // 远程查询
        order.setProductList(List.of(product));
        return order;
    }

+    /**
+     * 远程调用商品模块 --- 自己实现
+     *
+     * @param productId 商品id
+     * @return 商品对象
+     */
    private Product getProductFromRemote(Long productId) {
-        // 获取商品服务所有及其的 IP+port
+        // 1. 获取商品服务所有及其的 IP+port
        List<ServiceInstance> instances = discoveryClient.getInstances("service-product");
        ServiceInstance instance = instances.get(0);

@ -57,4 +65,22 @@ public class OrderServiceImpl implements OrderService {
        log.info("远程调用：{}", url);
        return restTemplate.getForObject(url, Product.class);
    }
+
+    /**
+     * 远程调用商品模块 --- 负载均衡
+     *
+     * @param productId 商品id
+     * @return 商品对象
+     */
+    private Product getProductFromRemoteWithLoadBalancer(Long productId) {
+        // 1. 获取商品服务所有及其的 IP+port
+        ServiceInstance instance = loadBalancerClient.choose("service-product");
+
+        // 远程URL
+        String url = "http://" + instance.getHost() + ":" + instance.getPort() + "/api/product/" + productId;
+
+        // 2. 远程发送请求
+        log.info("负载均衡远程调用：{}", url);
+        return restTemplate.getForObject(url, Product.class);
+    }
 }
--- a/cloud-demo/services/service-order/src/main/resources/templates/index.html
+++ b/cloud-demo/services/service-order/src/main/resources/templates/index.html
@ -3,7 +3,7 @@
 <head>
    <meta charset="UTF-8">
    <meta content="width=device-width, initial-scale=1.0" name="viewport">
-    <title>SpringCloud微服务复习教程</title>
+    <title>SpringCloud微服务复习教程-Order模块</title>
    <link href="https://fonts.googleapis.com/css2?family=Roboto:wght@300;400;500;700&family=Noto+Sans+SC:wght@300;400;500;700&display=swap"
          rel="stylesheet">
    <style>
@ -252,7 +252,7 @@
 <body>
 <header>
    <div class="container">
-        <h1>SpringCloud微服务复习教程</h1>
+        <h1>SpringCloud微服务复习教程-Order模块</h1>
        <p>掌握微服务架构的核心概念与实践，从服务注册发现到分布式配置，全面复习SpringCloud生态系统的关键组件</p>
    </div>
 </header>
--- a/cloud-demo/services/service-product/src/main/resources/templates/index.html
+++ b/cloud-demo/services/service-product/src/main/resources/templates/index.html
@ -3,7 +3,7 @@
 <head>
    <meta charset="UTF-8">
    <meta content="width=device-width, initial-scale=1.0" name="viewport">
-    <title>SpringCloud微服务复习教程</title>
+    <title>SpringCloud微服务复习教程-Product模块</title>
    <link href="https://fonts.googleapis.com/css2?family=Roboto:wght@300;400;500;700&family=Noto+Sans+SC:wght@300;400;500;700&display=swap"
          rel="stylesheet">
    <style>
@ -252,7 +252,7 @@
 <body>
 <header>
    <div class="container">
-        <h1>SpringCloud微服务复习教程</h1>
+        <h1>SpringCloud微服务复习教程-Product模块</h1>
        <p>掌握微服务架构的核心概念与实践，从服务注册发现到分布式配置，全面复习SpringCloud生态系统的关键组件</p>
    </div>
 </header>
--- a/mq-demo/ReadMe.md
+++ b/mq-demo/ReadMe.md
@ -103,6 +103,7 @@ rabbitmq:

 > [!NOTE]  
 > **@PostConstruct 注解**  
+>
 > **作用**：在Bean依赖注入完成后执行初始化方法（构造器之后，`afterPropertiesSet()`之前）。  
 >
 > **特点**：  
@ -116,6 +117,7 @@ rabbitmq:
 > - 避免耗时操作，推荐轻量级初始化  
 >
 > **替代方案**：  
+>
 > `InitializingBean`接口 或 `@Bean(initMethod="xxx")`  

 RabbitMQ配置