Dubbo Details: Dubbo Introduction and SpringBook Integration Dubbo+ZooKeeper

Introduction to Dubbo

1. What is Dubbo?

Dubbo is an open source Java-based high-performance RPC (a remote invocation) distributed service framework (SOA) for Alibaba, dedicated to providing high-performance and transparent RPC remote service invocation solutions, as well as SOA service governance solutions.

2. Dubbo Architecture

Node role description

node	Role Description
Provider	Exposure service provider
Consumer	Service consumers invoking remote services
Registry	Registry of Service Registration and Discovery
Monitor	Monitoring Center for Statistics of Service Call Number and Time
Container	Service Running Container

Call Relation Description

0. The service container is responsible for starting, loading and running the service provider.

1. The service provider registers its services with the registry at startup

2. Service consumers subscribe to the registry for services they need at startup

3. The registry returns the list of service provider addresses to consumers. If there is a change, the registry will push the change data to consumers based on long connections.

4. Service consumers, from the list of provider addresses, select one provider for invocation based on the soft load balancing algorithm, and if the invocation fails, choose another one for invocation.

5. Service consumers and providers, accumulating call times and call times in memory, sending statistic data to monitoring center at regular intervals every minute.

2. SpringBook Integration Dubbo+ZooKeeper Case

ZooKeeper address configuration: IP:Port1,IP:Port2, need to be modified according to the actual situation

1. Ways of using annotations

The project catalogue is structured as follows:

user-api: API Universal Interface

public interface UserService {
    String sayHello();
}

2) user-service: service provider

pom.xml:

<?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>dubbo</artifactId>
        <groupId>com.hand</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>user-service</artifactId>

    <properties>
        <spring-boot.version>2.1.1.RELEASE</spring-boot.version>
        <dubbo.version>2.7.3</dubbo.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <!-- Spring Boot -->
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring-boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

            <!-- Aapche Dubbo  -->
            <dependency>
                <groupId>org.apache.dubbo</groupId>
                <artifactId>dubbo-dependencies-bom</artifactId>
                <version>${dubbo.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

            <dependency>
                <groupId>org.apache.dubbo</groupId>
                <artifactId>dubbo</artifactId>
                <version>${dubbo.version}</version>
                <exclusions>
                    <exclusion>
                        <groupId>org.springframework</groupId>
                        <artifactId>spring</artifactId>
                    </exclusion>
                    <exclusion>
                        <groupId>javax.servlet</groupId>
                        <artifactId>servlet-api</artifactId>
                    </exclusion>
                    <exclusion>
                        <groupId>log4j</groupId>
                        <artifactId>log4j</artifactId>
                    </exclusion>
                </exclusions>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>com.hand</groupId>
            <artifactId>user-api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <!-- Dubbo Spring Boot Starter -->
        <dependency>
            <groupId>org.apache.dubbo</groupId>
            <artifactId>dubbo-spring-boot-starter</artifactId>
            <version>${dubbo.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.dubbo</groupId>
            <artifactId>dubbo</artifactId>
        </dependency>

        <!-- Zookeeper dependencies -->
        <dependency>
            <groupId>org.apache.dubbo</groupId>
            <artifactId>dubbo-dependencies-zookeeper</artifactId>
            <version>${dubbo.version}</version>
            <type>pom</type>
            <exclusions>
                <exclusion>
                    <groupId>org.slf4j</groupId>
                    <artifactId>slf4j-log4j12</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>
</project>

application.properties:

#The default value of dubbo.application.name is spring.application.name
spring.application.name=dubbo-auto-configuration-provider-demo
#To scan the basic package of dubbo components
dubbo.scan.base-packages=com.hand.service.impl
#dubbo protocol configuration
dubbo.protocol.name=dubbo
dubbo.protocol.port=8081
#dubbo Registry Address
dubbo.registry.address=zookeeper://IP:Port1,IP:Port2

Main startup class:

package com.hand.service;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;

@EnableAutoConfiguration
public class ServiceApplication {

    public static void main(String[] args) {
        SpringApplication.run(ServiceApplication.class);
    }

}

Interface implementation class:

package com.hand.service.impl;

import com.hand.user.service.UserService;
import org.apache.dubbo.config.annotation.Service;

@Service(version = "1.0.0")
public class UserServiceImpl implements UserService {
    public String sayHello() {
        return "hello world";
    }
}

3), user-web: service caller

pom.xml:

<?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>dubbo</artifactId>
        <groupId>com.hand</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>user-web</artifactId>

    <properties>
        <spring-boot.version>2.1.1.RELEASE</spring-boot.version>
        <dubbo.version>2.7.3</dubbo.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <!-- Spring Boot -->
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring-boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!-- Aapche Dubbo  -->
            <dependency>
                <groupId>org.apache.dubbo</groupId>
                <artifactId>dubbo-dependencies-bom</artifactId>
                <version>${dubbo.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>org.apache.dubbo</groupId>
                <artifactId>dubbo</artifactId>
                <version>${dubbo.version}</version>
                <exclusions>
                    <exclusion>
                        <groupId>org.springframework</groupId>
                        <artifactId>spring</artifactId>
                    </exclusion>
                    <exclusion>
                        <groupId>javax.servlet</groupId>
                        <artifactId>servlet-api</artifactId>
                    </exclusion>
                    <exclusion>
                        <groupId>log4j</groupId>
                        <artifactId>log4j</artifactId>
                    </exclusion>
                </exclusions>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <dependencies>
        <dependency>
            <groupId>com.hand</groupId>
            <artifactId>user-api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <!-- Dubbo Spring Boot Starter -->
        <dependency>
            <groupId>org.apache.dubbo</groupId>
            <artifactId>dubbo-spring-boot-starter</artifactId>
            <version>${dubbo.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.dubbo</groupId>
            <artifactId>dubbo</artifactId>
            <version>${dubbo.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- Zookeeper dependencies -->
        <dependency>
            <groupId>org.apache.dubbo</groupId>
            <artifactId>dubbo-dependencies-zookeeper</artifactId>
            <version>${dubbo.version}</version>
            <type>pom</type>
            <exclusions>
                <exclusion>
                    <groupId>org.slf4j</groupId>
                    <artifactId>slf4j-log4j12</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>
</project>

application.properties:

#The default value of dubbo.application.name is spring.application.name
spring.application.name=dubbo-auto-configure-consumer-demo
#dubbo Registry Address
dubbo.registry.address=zookeeper://IP:Port1,IP:Port2

Main startup class:

package com.hand.user;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

Caller:

package com.hand.user.web;

import com.hand.user.service.UserService;
import org.apache.dubbo.config.annotation.Reference;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class UserController {
    @Reference(version = "1.0.0")
    private UserService userService;

    @RequestMapping("/sayHello")
    public String sayHello() {
        return userService.sayHello();
    }
}

GitHub address: https://github.com/hxt970311/dubbo-spring boot-annotation-demo

2. Configuration using xml

1), user-service: service provider

Add a new provider.xml to configure the corresponding information of the service provider

<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:dubbo="http://dubbo.apache.org/schema/dubbo"
       xmlns="http://www.springframework.org/schema/beans"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
       http://dubbo.apache.org/schema/dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd">
    <dubbo:application name="dubbo-auto-configure-consumer-demo"/>
    <dubbo:registry address="zookeeper://IP:Port1,IP:Port2"/>
    <dubbo:reference id="userService" check="false" interface="com.hand.user.service.UserService"/>
</beans>

Remove the @Service annotation from the specific service implementation class

package com.hand.service.impl;

import com.hand.user.service.UserService;

public class UserServiceImpl implements UserService {
    public String sayHello() {
        return "hello world";
    }
}

Add the @ImportResource annotation to the startup class

package com.hand.service;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.ImportResource;

@ImportResource("provider.xml")
@EnableAutoConfiguration
public class ServiceApplication {

    public static void main(String[] args) {
        SpringApplication.run(ServiceApplication.class);
    }

}

2) user-web: service consumers

New consumer.xml

<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:dubbo="http://dubbo.apache.org/schema/dubbo"
       xmlns="http://www.springframework.org/schema/beans"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
       http://dubbo.apache.org/schema/dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd">
    <dubbo:application name="dubbo-auto-configuration-provider-demo"/>
    <dubbo:registry address="zookeeper://IP:Port1,IP:Port2"/>
    <dubbo:protocol name="dubbo" port="8081"/>
    <bean id="userService" class="com.hand.service.impl.UserServiceImpl"/>
    <dubbo:service interface="com.hand.user.service.UserService" ref="userService"/>
</beans>

Add the @ImportResource annotation to the startup class

package com.hand.user;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ImportResource;

@ImportResource("consumer.xml")
@SpringBootApplication
public class WebApplication {
    public static void main(String[] args) {
        SpringApplication.run(WebApplication.class);
    }
}

Replace @Reference with Spring's @Autowire annotation

package com.hand.user.web;

import com.hand.user.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class UserController {
    @Autowired
    private UserService userService;

    @RequestMapping("/sayHello")
    public String sayHello() {
        return userService.sayHello();
    }
}

GitHub address: https://github.com/hxt970311/dubbo-spring boot-xml-demo

Keywords: Dubbo Spring Apache Zookeeper

Added by Nightseer on Fri, 23 Aug 2019 11:10:10 +0300

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