Consul service registration and discovery

Stand-alone version

1.Consul brief introduction

Consul Official website

Consul It is a set of open source distributed services Current and configuration management system , from HashiCorp Company use Go Language development .

It provides service governance in microservice system . Configure central control bus and other functions . Each of these functions can be used separately as needed , It can also be a Use to form a comprehensive service network , All in all Consul Provides a complete service grid solution .

It has many advantages . Include : be based on raft agreement , Simple comparison ; Support health checks Support at the same time HTTP and DNS The protocol supports cross data center WAN Clusters provide graphical interfaces across platforms , Support Linux、Mac、 Windows.

1.1 What can I do? ？

1.2 Consul Download address
1.3 How do you play? ？
Chinese version of the course

2. Install and run Consul

2.1 Official website installation instructions
Official website installation instructions
mac System installation Consul see
mac install brew and Consul

3. Service providers

3.1 newly build Module Payment services provider8006
cloud-providerconsul-payment8006
3.2 modify pom.xml

<dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-consul-discovery</artifactId>
        </dependency>

        <dependency>
            <groupId>com.zhang.springcloud</groupId>
            <artifactId>cloud-api-commons</artifactId>
            <version>${project.version}</version>
        </dependency>

        <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>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
    </dependencies>

3.3 establish application.yml

#####consul Service port number 
server:
  port: 8006

spring:
  application:
    name: consul-provider-payment
####consul Address of Registration Center 
  cloud:
    consul:
      host: localhost
      discovery:
        #hostname: 127.0.0.1
        service-name: ${spring.application.name}

3.4 Main startup class

@SpringBootApplication
@EnableDiscoveryClient
public class PaymentMain8006 {
    public static void main(String[] args) {
        SpringApplication.run(PaymentMain8006.class,args);
    }
}

3.5 controller class

@RestController
@Slf4j
public class PaymentController {
    @Value("${server.port}")
    private String serverPort;

    @RequestMapping("/payment/consul")
    public String paymentConsul(){
        return "springcloud with consul: "+serverPort+"\t"+ UUID.randomUUID().toString();
    }
}

4. Serving consumers

4.1 newly build Module Consumer service order8006
cloud-consumerconsul-order80
4.2 modify pom.xml

<dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-consul-discovery</artifactId>
        </dependency>
        <dependency>
            <groupId>com.zhang.springcloud</groupId>
            <artifactId>cloud-api-commons</artifactId>
            <version>${project.version}</version>
        </dependency>
        <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>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
    </dependencies>

4.3 establish application.yml file

###consul Service port number 
server:
  port: 80

spring:
  application:
    name: cloud-consumer-order
###consul Registry Center 
  cloud:
    consul:
      host: localhost
      port: 8500
      discovery:
        #hostname:127.0.0.1
        service-name: ${spring.application.name}

4.4 Main startup class

@SpringBootApplication
@EnableDiscoveryClient
public class OrderConsulMain80 {
    public static void main(String[] args) {
        SpringApplication.run(OrderConsulMain80.class,args);
    }
}

4.5 To configure Bean

@Configuration
public class ApplicationContextConfig {

    @Bean
    @LoadBalanced
    public RestTemplate getRestTemplate(){
        return new RestTemplate();
    }
}

4.6 controller

@RestController
@Slf4j
public class OrderConsulController {
    public static final String INVOKE_URL = "http://consul-provider-payment";

    @Resource
    private RestTemplate restTemplate;

    @GetMapping("/consumer/payment/consul")
    public String paymentInfo(){
        return restTemplate.getForObject(INVOKE_URL+"/payment/consul",String.class);
    }
}

Be careful ：

Eureka 、 Zookeeper 、 Consul The similarities and differences between the three registries ：

What is the CAP?

At most, two can be satisfied at the same time .

CAP The core of the theory is : A distributed system can't satisfy the consistency well at the same time , Availability and partition fault tolerance are three requirements , therefore , according to CAP The principle will NoSQL The database is divided into satisfying CA principle 、 Satisfy CP Principles and satisfaction AP Three categories of principles :

CA- Single point cluster , Meet consistency , Availability system , Usually not very strong in scalability .

CP Meet consistency , Partition tolerates the necessary system ,. Usually the performance is not very high .

**AP ** Meet availability , Partition tolerant system , Generally, there may be lower requirements for consistency .

AP framework

When network partition appears , To ensure availability , System B You can return the old value , Ensure the availability of the system . Conclusion : Violate one Sexual nature C The requirements of , Only for availability and partition fault tolerance , namely AP

CP framework

When network partition appears , To ensure consistency , You have to reject the request , Otherwise, the consequent conclusion cannot be guaranteed : Violation of availability A The requirements of , Only satisfied - Consistency and partition fault tolerance , namely CP