What is Consul? Consul is a service mesh solution providing a full featured control plane with service discovery, configuration, and segmentation functionality. Each of these features can be used individually as needed, or they can be used together to build a full service mesh. Consul requires a data plane and supports both a proxy and native integration model. Consul ships with a simple built-in proxy so that everything works out of the box, but also supports 3rd party proxy integrations such as Envoy. link Consul是一个服务网格解决方案,它提供了一个功能齐全的控制平面,具有服务发现、配置和分段功能。这些特性中的每一个都可以根据需要单独使用,也可以一起用于构建全服务网格。Consul需要一个数据平面,并支持代理和本机集成模型。Consul船与一个简单的内置代理,使一切工作的开箱即用,但也支持第三方代理集成,如Envoy。
consul 英 [ˈkɒnsl] 美 [ˈkɑːnsl] n. 领事
Consul是一套开源的分布式服务发现和配置管理系统,由HashiCorp 公司用Go语言开发。
提供了微服务系统中的服务治理、配置中心、控制总线等功能。这些功能中的每一个都可以根据需要单独使用,也可以一起使用以构建全方位的服务网格,总之Consul提供了一种完整的服务网格解决方案。
它具有很多优点。包括:基于raft协议,比较简洁;支持健康检查,同时支持HTTP和DNS协议支持跨数据中心的WAN集群提供图形界面跨平台,支持Linux、Mac、Windows。
The key features of Consul are:
能干嘛?
windows版解压缩后,得consul.exe,打开cmd
consul -v:DELL@FRXcomputer MINGW64 /d/DevelopTools/Consul/consul_1.13.1_windows_amd64
$ ./consul.exe --version
Consul v1.13.1
Revision c6d0f9ec
Build Date 2022-08-11T19:07:00Z
Protocol 2 spoken by default, understands 2 to 3 (agent will automatically use protocol >2 when speaking to compatible agents)consul agent -dev:浏览器输入 - http://localhost:8500/ - 打开Consul控制页。

<?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>cloud2020</artifactId>
<groupId>com.frx01.springcloud</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>cloud-providerconsul-payment8006</artifactId>
<dependencies>
<!-- 引入自己定义的api通用包,可以使用Payment支付Entity -->
<dependency>
<groupId>com.frx01.springcloud</groupId>
<artifactId>cloud-api-commons</artifactId>
<version>${project.version}</version>
</dependency>
<!--SpringCloud consul-server -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-consul-discovery</artifactId>
</dependency>
<!-- SpringBoot整合Web组件 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<!--日常通用jar包配置-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>cn.hutool</groupId>
<artifactId>hutool-all</artifactId>
<version>RELEASE</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>cn.hutool</groupId>
<artifactId>hutool-all</artifactId>
<version>RELEASE</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>###consul服务端口号
server:
port: 8006
spring:
application:
name: consul-provider-payment
####consul注册中心地址
cloud:
consul:
host: localhost
port: 8500
discovery:
#hostname: 127.0.0.1
service-name: ${spring.application.name}@SpringBootApplication
@EnableDiscoveryClient
public class PaymentMain8006 {
public static void main(String[] args) {
SpringApplication.run(PaymentMain8006.class,args);
}
}@RestController
@Slf4j
public class PaymentController {
@Value("${server.port}")
private String serverPort;
@RequestMapping(value = "/payment/consul")
public String paymentConsul(){
return "springcloud with consul:"+serverPort+"\t"+ UUID.randomUUID().toString();
}
}6.验证测试


<?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>cloud2020</artifactId>
<groupId>com.frx01.springcloud</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>cloud-consumerconsul-order80</artifactId>
<dependencies>
<!--SpringCloud consul-server -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-consul-discovery</artifactId>
</dependency>
<!-- SpringBoot整合Web组件 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<!--日常通用jar包配置-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
</project>###consul服务端口号
server:
port: 81
spring:
application:
name: cloud-consumer-payment
####consul注册中心地址
cloud:
consul:
host: localhost
port: 8500
discovery:
#hostname: 127.0.0.1
service-name: ${spring.application.name}80端口被占用了 ,我换为了81
@SpringBootApplication
@EnableDiscoveryClient
public class OrderConsulMain80 {
public static void main(String[] args) {
SpringApplication.run(OrderConsulMain80.class,args);
}
}@Configuration
public class ApplicationContextConfig {
@Bean
@LoadBalanced
public RestTemplate restTemplate(){
return new RestTemplate();
}
}@RestController
public class OrderConsulController {
public static final String INVOKE_URL = "http://consul-provider-payment";
@Resource
private RestTemplate restTemplate;
@GetMapping(value = "/consumer/payment/consul")
public String paymentInfo(){
String result = restTemplate.getForObject(INVOKE_URL+"/payment/consul",String.class);
return result;
}
}

组件名 | 语言CAP | 服务健康检查 | 对外暴露接口 | Spring Cloud集成 |
|---|---|---|---|---|
Eureka | Java | AP | 可配支持 | HTTP |
Consul | Go | CP | 支持 | HTTP/DNS |
Zookeeper | Java | CP | 支持客户端 | 已集成 |
CAP:

最多只能同时较好的满足两个。
CAP理论的核心是:一个分布式系统不可能同时很好的满足一致性,可用性和分区容错性这三个需求。
因此,根据CAP原理将NoSQL数据库分成了满足CA原则、满足CP原则和满足AP原则三大类:
AP架构(Eureka)
当网络分区出现后,为了保证可用性,系统B可以返回旧值,保证系统的可用性。
结论:违背了一致性C的要求,只满足可用性和分区容错,即AP

CP架构(ZooKeeper/Consul)
当网络分区出现后,为了保证一致性,就必须拒接请求,否则无法保证一致性。
结论:违背了可用性A的要求,只满足一致性和分区容错,即CP。

CP 与 AP 对立同一的矛盾关系。