一、Eureka自我保护机制
1、产生原因
为了防止EurekaClient可以正常运行,但是与EurekaServer网络不通的情况下,EurekaServer不会将EurekaClient剔除。
ALLEN-MEMBER服务有两个,但是8110服务已经宕机,访问ALLEN-ORDER服务,仍会调用8110服务,报错
2、原理
3、开启环境
- 在本地环境禁止自我保护机制
- 在生产环境开启自我保护机制
(1)eureka-server
eureka:
server:
# 测试时关闭自我保护机制
enable-self-preservation: false
# 多少毫秒剔除服务
eviction-interval-timer-in-ms: 2000
(2)eureka-client
eureka:
instance:
# Eureka客户端向服务端发送心跳的时间间隔,单位是秒
lease-renewal-interval-in-seconds: 1
# Eureka服务端在收到最后一次心跳后等待的时间上限,单位是秒,超过则剔除
lease-expiration-duration-in-seconds: 2
注意:注册中心会有30s的缓存,服务剔除后,30s后才不会报错
二、Zookeeper注册中心
1、注册中心
zookeeper节点类型: 临时节点
(1)pom.xml
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-zookeeper-discovery</artifactId>
</dependency>
(2)yml
server:
port: 9000
spring:
application:
#服务别名
name: zk-member
cloud:
zookeeper:
#注册连接
connect-string: 127.0.0.1:2181
(3)Controller
@RestController
public class MemberController {
@RequestMapping("/getMember")
public String getMember() {
return "获取会员信息";
}
}
(4)启动类
备注:经测试@EnableDiscoveryClient注解不添加,同样实现效果
@SpringBootApplication
@EnableDiscoveryClient
public class ZkApplication {
public static void main(String[] args) {
SpringApplication.run(ZkApplication.class, args);
}
}
(5)结果查看
工具类:ZooInspector.zip
解压后 执行java -jar …\ZooInspector\build\zookeeper-dev-ZooInspector.jar
2、整合Ribbon
(1)pom.xml 同上
(2)application.yml 同上
(3)controller
@RestController
public class OrderController {
@Autowired
private RestTemplate restTemplate;
@RequestMapping("/getOrder")
public String getOrder() {
String url = "http://zk-member/getMember";
String result = restTemplate.getForObject(url, String.class);
System.err.println("订单请求:" + result);
return result;
}
}
(4)启动类
@SpringBootApplication
public class OrderApplication {
public static void main(String[] args) {
SpringApplication.run(OrderApplication.class, args);
}
@Bean
@LoadBalanced
public RestTemplate restTemplate() {
return new RestTemplate();
}
}
三、consul注册中心
1、consul注册中心
到官网 https://www.consul.io/downloads 进行下载
启动: consul agent -dev -ui -node=cy
访问http://localhost:8500
2、整合
(1)pom.xml
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-consul-discovery</artifactId>
</dependency>
(2)application.yml
server:
port: 8510
spring:
application:
name: consul-member
cloud:
consul:
host: localhost
port: 8500
discovery:
hostname: 192.168.1.1
# 心跳开启,否则服务检测会爆红
heartbeat:
enabled: true
(3)controller 同上
(4)启动类 同上
四、DiscoveryClient
作用:获取到注册中心服务上的列表信息
@Autowired
private DiscoveryClient discoveryClient;
@RequestMapping("/getMemberDiscovery")
public List<ServiceInstance> getMemberDiscovery(){
List<ServiceInstance> list = discoveryClient.getInstances("zk-member");
for (ServiceInstance instance: list) {
URI uri = instance.getUri();
System.err.println(uri);
}
return list;
}