Shulou(Shulou.com)06/01 Report--

This article mainly explains "how to get started with dubbo". Interested friends may wish to take a look. The method introduced in this paper is simple, fast and practical. Let's let the editor take you to learn how to get started with dubbo.

I. the basic principles of dubbo

The dubbo architecture diagram is as follows:

Description of invocation relationship:

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

1. Upon startup, the service provider registers the services it provides with the registry.

two。 Service consumers subscribe to the services they need from the registry when they start up.

3. The registry returns a list of service provider addresses to the consumer, and if there is a change, the registry will push the change data to the consumer based on the persistent connection.

4. The service consumer, from the provider address list, chooses one provider to call based on the soft load balancing algorithm, and then chooses another one if the call fails.

5. Service consumers and providers accumulate the number of calls and call time in memory and regularly send statistics to the monitoring center every minute.

Introduction to getting started with demo

The demo consists of three projects, namely:

Service provider project: provider

Service consumer project: consumer

Common Service Interface Project: api

The dependencies are shown in the figure:

The api project is a jar project that packages the generated jar into a maven repository and imports it as a dependency on provider and consumer projects.

Third, the concrete implementation of dubbo- remote call (RPC)

1. Download and configure zookeeper

Start the zookeeper before starting the service provider project, because we need to register the service provider with the zookeeper before it can be discovered and invoked by the service consumer.

Zookeeper will not be introduced in detail here, but a simple summary is the distributed service governance framework, which is used for service registration and discovery, remote invocation functions, and so on.

Zookeeper download

Http://zookeeper.apache.org/

Extract and modify the configuration

After the zookeeper download is completed, extract it to the appropriate directory, then go to the conf directory of zookeeper, find the zoo_sample.cfg file and rename it to zoo.cfg, then open the file, and modify the dataDir and dataLogDir as follows:

DataDir=E:\\ Soft\\ zookeeper-3.4.6\\ data

DataLogDir=E:\\ Soft\\ zookeeper-3.4.6\\ log

Change to the directory of your local hard drive

Start zookeeper

Go to the bin directory of zookeeper, double-click zkServer.cmd, and start zookeeper

2.dubbo Interface Service api Project

Create a new maven project api and pay attention to changing the packaging method in its pom.xml to jar

Then create a new DemoService interface under the com.dubbo.api.service package, as follows:

Public interface DemoService {

String sayHello (String name)

}

The project structure is shown in the figure:

Then package the project (just install it), find the jar in the E:\ temp\ api\ target\ directory, package it to the local maven warehouse, open the cmd command window, and enter the following command:

Mvn install:install-file-Dfile=E:\ temp\ api\ target\ api.jar-DgroupId=com.dubbo.api-DartifactId=api-Dversion=1.0.0-Dpackaging=jar-DgeneratePom=true-DcreateChecksum=true

Note: the jar path should be your own path

3.dubbo Service provider provider Project

Create a new maven project provider and add the following dependencies to pom.xml:

Com.dubbo.api

Api

1.0.0

Com.alibaba

Dubbo

2.5.3

Com.101tec

Zkclient

0.10

Org.springframework

Spring-context

4.0.5.RELEASE

The above generated api interface dependencies, dubbo dependencies, zookeeper client-side dependencies, and necessary dependencies for starting the project are introduced here

Then create a new DemoServiceImp under the com.dubbo.provider.service.impl package and implement the DemoService interface, as follows:

Public class DemoServiceImpl implements DemoService {

@ Override

Public String sayHello (String name) {

Return "Hello" >}

Then create a new provider.xml file under resources, and configure it as follows:

/ / Note that you need to introduce constraints into eclipse, and constrain the dubbo.xsd file after dubbo.2.5.3.jar decompression.

Then create a new Provider directly under java to start the project:

Public class Provider {

Public static void main (String [] args) throws IOException {

ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext ("provider.xml")

Context.start ()

System.out.println ("dubbo service provider started.")

System.in.read (); / / Press any key to exit

}

}

The provider project structure is shown in the figure:

Then run the main function directly-the dubbo service provider has started!

4.dubbo Service Consumer consumer Project

Create a new maven project consumer and add the following dependencies to pom.xml:

Com.dubbo.api

Api

1.0.0

Com.alibaba

Dubbo

2.5.3

Com.101tec

Zkclient

0.10

Org.springframework

Spring-context

4.0.5.RELEASE

The same dependencies are added by the provider project.

Then create a new comsumer.xml under resources and configure the service consumer as follows:

Then create a new Consumer.class under java to start the project, as follows:

Public class Consumer {

Public static void main (String [] args) throws IOException {

ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext ("consumer.xml")

Context.start ()

System.out.println ("dubbo service consumer has started...")

DemoService demoService = (DemoService) context.getBean ("demoService"); / / get remote service agent

String hello = demoService.sayHello ("world"); / / execute remote methods

System.out.println (hello); / / display the result of the call

System.in.read (); / / Press any key to exit

}

}

Start the project and display the result of the call, as shown in the figure:

At this point, the remote call to dubbo is completed. The following is about the dubbo-admin Management console

4. Dubbo-admin Management console

Dubbo services can be better managed through dubbo-admin.

First download the war package of dubbo-admin at:

When the download is complete, copy the dubbo-admin-2.6.0.war to the webapps directory of tomcat. Then start tomcat and visit

Http://localhost:8080/dubbo-admin-2.6.0/

You can also rename dubbo-admin-2.6.0 to access http://localhost:8080/dubbo-admin directly when you access dubbo-admin.

Both user name and password are root

After logging in, you can manage the dubbo service through the web page, as shown in the figure:

At this point, I believe you have a deeper understanding of "how to get started with dubbo". You might as well do it in practice. Here is the website, more related content can enter the relevant channels to inquire, follow us, continue to learn!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.