一、原始服务的调用

通过网页的请求，这个网页请求到另一个网页，利用nginx做负载均衡。

消费者

1
2
3
4
5
6
7
8
9
10
@RestController
public class IndexController {
    @Autowired
    RestTemplate restTemplate;
    @RequestMapping("/indexClient.do")
    public String index() {
        ResponseEntity responseEntity = restTemplate.getForEntity("http://127.0.0.1/index.do",String.class);
        return responseEntity.getBody();
    }
}

RestTemplate：

是Spring用于同步client端的核心类，简化了与http服务的通信，并满足RestFul原则，程序代码可以给它提供URL，并提取结果。默认情况下，RestTemplate默认依赖jdk的HTTP连接工具。当然你也可以 通过setRequestFactory属性切换到不同的HTTP源，比如Apache HttpComponents、Netty和OkHttp。

生产者：1111

1
2
3
4
5
6
7
8
9
10
11
@RestController
public class IndexController {
    @RequestMapping("/index.do")
    public List> index() {
        List> list= new ArrayList();
        Map map = new HashMap<>();
        map.put("key","port:1111");
        list.add(map);
        return list;
    }
}

生产者：1121

1
2
3
4
5
6
7
8
9
10
11
@RestController
public class IndexController {
    @RequestMapping("/index.do")
    public List> index() {
        List> list= new ArrayList();
        Map map = new HashMap<>();
        map.put("key","port:1121");
        list.add(map);
        return list;
    }
}

nginx负载均衡

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
upstream backser {
	server 127.0.0.1:1111;
	server 127.0.0.1:1121;
}

   server {
       listen       80;
       server_name  localhost;

       #charset koi8-r;

       #access_log  logs/host.access.log  main;

       location / {
           root   html;
           index  index.html index.htm;
		proxy_pass http://backser;
       }
   }

二、 服务注册中心eureka

Eureka 是 Netflix 开发的，一个基于 REST 服务的，服务注册与发现的组件

它主要包括两个组件：Eureka Server 和 Eureka Client

  • Eureka Client：一个Java客户端，用于简化与 Eureka Server 的交互（通常就是微服务中的客户端和服务端）
  • Eureka Server：提供服务注册和发现的能力（通常就是微服务中的注册中心）

Eureka Server依赖包

1
2
3
4
<dependency>
    <groupId>org.springframework.cloudgroupId>
    <artifactId>spring-cloud-starter-netflix-eureka-serverartifactId>
dependency>

Eureka Client依赖包

1
2
3
4
<dependency>
	<groupId>org.springframework.cloudgroupId>
	<artifactId>spring-cloud-starter-netflix-eureka-clientartifactId>
dependency>

依赖管理

1
2
3
4
5
6
7
8
9
10
11
<dependencyManagement>
  <dependencies>
    <dependency>
      <groupId>org.springframework.cloudgroupId>
      <artifactId>spring-cloud-dependenciesartifactId>
      <version>${spring-cloud.version}version>
      <type>pomtype>
      <scope>importscope>
    dependency>
  dependencies>
dependencyManagement>

Server application.yml

1
2
3
4
5
6
7
8
9
10
11
12
server:
  port: 9000
eureka:
  server:
    enable-self-preservation: false
  instance:
    hostname: localhost
  client:
    register-with-eureka: false
    fetch-registry: false
    service-url:
      default-zone: http://${eureka.instance.hostname}:${server.port}/eureka

ServerApplication

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

client application.yml

1
2
3
4
5
6
7
8
9
server:
  port: 1111
eureka:
  client:
    service-url:
      defaultZone: http://127.0.0.1:9000/eureka
spring:
  application:
    name: shadow-order-service-1111

ClientApplication

1
2
3
4
5
6
7
@SpringBootApplication
@EnableDiscoveryClient
public class OrderApplication1111 {
    public static void main(String[] args) {
        SpringApplication.run(OrderApplication1111.class, args);
    }
}

三、dubbo zookeeper

zookeeper服务器启动的逻辑：

1、初始化配置

2、监听端口

3、初始化DataTree

4、领导者选举