Dubbo-Serivcecomb | 中文

Dubbo-Serivcecomb provide extensions for Apache Dubbo to using Cloud Service Engine, so that Dubbo users can use service center, config center and governance features.

Dubbo's versions before 2.7.x interface based discovery is used. After 2.7.x, users can also use service based discovery, which is widely used in Spring Cloud, ServiceComb and Istio.

Dubbo-ServiceComb provides service based discovery for all Dubbo's versions includes versions before 2.7.x. So that different versions of Dubbo applications can be managed by Cloud Service Engine.

Supported versions

Before reading the next contents, check the supported versions in different branch.

Dubbo Microservice Concepts vs Dubbo-ServiceComb Concepts

• Dubbo Microservice Concepts

  • application: microservice.
  • service：java interface。

• Dubbo-ServiceComb Concepts

  • microservice: microservice.
  • application: A group of microservices fulfils user applications.
  • schema: java interface.

In the following chapters we use Dubbo-ServiceComb Concepts.

Dubbo Governance vs Dubbo-ServiceComb Governance

When Dubbo application starts up, it registers all governance properties to register center. Users change governance properties from Dubbo Admin, and Dubbo Admin will push changes to application. The internal governance feature will read the change and follow the instructions.

Dubbo-ServiceComb registers governance properties to config center. Users change configurations throw config center, and config center will push all change to the application.

Benefits and Drawbacks

• Benefits

  • Add Service Based Discovery, so that different version can be manged together. And can inter-operate with other microservice framework.
  • Much less microservice instances. Each microservice has only one instance, while Dubbo instances is compared to interfaces.
  • Same governance procedure with Spring Cloud, ServiceComb. So that we can deploy different services together and managed with the same rule.

• Drawbacks

  • Dubbo allows one interface has many implementations in different microservices, this is very useful for microservice split and combination.
  • Dubbo uses Dubbo Admin to change governance properties, while Dubbo ServiceComb cannot.

Quick Start

This quick start can be found in dubbo-servicecomb-sample.

• Download Local CSE, run start.bat. After start up, using http://localhost:30106/ to open the console.

• Config POM in project

    ```
    <dependency>
      <groupId>com.huaweicloud.dubbo-servicecomb</groupId>
      <artifactId>dubbo-servicecomb-service-center</artifactId>
    </dependency>
    <dependency>
      <groupId>com.huaweicloud.dubbo-servicecomb</groupId>
      <artifactId>dubbo-servicecomb-config-center</artifactId>
    </dependency>
    ```
  

• Start Up using Spring

  In Spring Component scan, add classpath*:spring/dubbo-servicecomb.xml.

    ```
    public class PriceApplication {
      public static void main(String[] args) throws Exception {
        try {
          ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(
              "classpath*:spring/dubbo-provider.xml", "classpath*:spring/dubbo-servicecomb.xml");
          context.start();
          System.in.read();
        } catch (Throwable e) {
          e.printStackTrace();
        }
      }
    }
    ```
  

• Start Up using Spring Boot

In Spring Boot Component scan, add classpath*:spring/dubbo-servicecomb.xml.

    ```
    @SpringBootApplication
    @ImportResource({"classpath*:spring/dubbo-provider.xml", "classpath*:spring/dubbo-servicecomb.xml"})
    public class PriceApplication {
      public static void main(String[] args) throws Exception {
        try {
          SpringApplication.run(PriceApplication.class);
        } catch (Throwable e) {
          e.printStackTrace();
        }
      }
    }
    ``` 

In POM, add

    ```
    <dependency>
      <groupId>com.huaweicloud.dubbo-servicecomb</groupId>
      <artifactId>dubbo-servicecomb-spring-boot</artifactId>
    </dependency>
    ```

• using service center

  In Spring configuration files, change zookeeper to service center.

    ```xml
    <dubbo:registry address="sc://127.0.0.1:30100"/>
    ```
  

  The address is ignored and configured in dubbo.properties.

• In dubbo.properties configurations

  The configurations include microservice name, version and address of service center, config center.

    ```properties        
    dubbo.servicecomb.service.application=discovery
    dubbo.servicecomb.service.name=price-provider
    dubbo.servicecomb.service.version=1.0.0
    dubbo.servicecomb.service.environment=production
    #### END
    
    dubbo.servicecomb.registry.address=http://127.0.0.1:30100
    
    dubbo.servicecomb.config.address=http://127.0.0.1:30113
    ```
  

• add governance configurations

dubbo.servicecomb.governance: {"providerInfos":[{"serviceName":"price-provider","schemaInfos":[{"schemaId":"com.huaweicloud.it.price.PriceService","parameters":{"timeout":5000}}]}]}

Using Cloud Service Engine

Change address to Cloud Service Engine address and configure HTTPS, AK/SK.

#### service center address ####
dubbo.servicecomb.registry.address=https://cse.cn-north-1.myhuaweicloud.com

#### config center address ####
dubbo.servicecomb.config.address=https://cse.cn-north-1.myhuaweicloud.com

#### enabled SSL  ####
dubbo.servicecomb.ssl.enabled=true

#### Configure AK/SK  ####
dubbo.servicecomb.credentials.enabled=true
dubbo.servicecomb.credentials.accessKey= Your access key
dubbo.servicecomb.credentials.secretKey= Your secret key
dubbo.servicecomb.credentials.project=cn-north-1

Configurations Reference

#### Microservices ####
# Application
dubbo.servicecomb.service.application=discovery
# Microservice Name
dubbo.servicecomb.service.name=price-provider
# Version, default is 1.0.0.0
dubbo.servicecomb.service.version=1.0.0
# Environment, default is Empty.  Options: development, testing, acceptance, production
# dubbo.servicecomb.service.environment=production
# Project 
# dubbo.servicecomb.service.project=
#### END

#### Microservice Instance ####
# Initial status. Options: UP, DOWN, STARTING, OUTOFSERVICE
# dubbo.servicecomb.instance.initialStatus=UP
#### END

#### service center address ####
dubbo.servicecomb.registry.address=http://127.0.0.1:30100

#### config center address ####
dubbo.servicecomb.config.address=http://127.0.0.1:30113

#### SSL options  ####
#dubbo.servicecomb.ssl.enabled=true
# ssl engine. Options JDK or OPENSSL
#dubbo.servicecomb.ssl.engine=
# ssl protocols, default to TLSv1.2
#dubbo.servicecomb.ssl.protocols=
# ssl ciphers, default to TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
#dubbo.servicecomb.ssl.ciphers=
#dubbo.servicecomb.ssl.authPeer=false
#dubbo.servicecomb.ssl.trustStore=
#dubbo.servicecomb.ssl.trustStoreType=
#dubbo.servicecomb.ssl.trustStoreValue=
#dubbo.servicecomb.ssl.keyStore=
#dubbo.servicecomb.ssl.keyStoreType=
#dubbo.servicecomb.ssl.keyStoreValue=
#dubbo.servicecomb.ssl.crl=
#dubbo.servicecomb.ssl.sslCustomClass=

#### AK/SK Options  ####
#dubbo.servicecomb.credentials.enabled=true
#dubbo.servicecomb.credentials.accessKey=
#dubbo.servicecomb.credentials.secretKey=
#dubbo.servicecomb.credentials.cipher=
#dubbo.servicecomb.credentials.project=cn-south-1