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What is Dubbo? How to use Dubbo? These problems may be encountered in our daily work. Through these questions, I hope you can gain more. Here are the details of uncovering these problems.

Introduction to Dubbox

Dubbox is a distributed service framework, its predecessor is Alibaba open source project Dubbo, used by domestic e-commerce and Internet projects, later Alibaba stopped the maintenance of the project, Dangdang will be optimized on the basis of Dubbo, and continue to maintain, in order to distinguish with the original Dubbo, so named Dubbox.

Dubbox is committed to providing high-performance and transparent RPC remote service invocation solutions, as well as SOA service governance solutions. To put it simply, dubbox is a service framework. If there is no distributed requirement, it does not need to be used. It is only when it is distributed that there is a requirement for a distributed service framework like dubbox, and it is essentially a service invocation thing. To put it bluntly, it is a distributed framework for remote service invocation.

Node role description:

Provider: the provider of the exposed service. Consumer: the service consumer that invokes the remote service. Registry: the registry for service registration and discovery. Monitor: the monitoring center that calculates the call time and call time of the service. Container: the service running container.

Description of invocation relationship:

The service container is responsible for starting, loading, and running the service provider. Upon startup, the service provider registers the services it provides with the registry. Service consumers subscribe to the services they need from the registry when they start up. The registry returns the list of service provider addresses to the consumer. If there is any change, the registry will push based on the long connection.

Send change data to consumers. The service consumer, from the provider address list, chooses a provider to call based on the soft load balancing algorithm.

If the call fails, choose another call. Service consumers and providers accumulate the number and time of calls in memory and regularly send statistics every minute

Data to the monitoring center. Zookeeper introduction

It is officially recommended to use the zookeeper registry. The registry is responsible for the registration and search of the service address, which is equivalent to the directory service. Service providers and consumers only interact with the registry at startup, and the registry does not forward requests, so there is less pressure.

Zookeeper, a sub-project of Apacahe Hadoop, is a tree directory service that supports change push and is suitable to be used as a registry for Dubbox services. It has high industrial intensity and can be used in production environment.

Installation of Zookeeper in Linux system

Installation steps:

Step 1: install jdk

Step 2: upload the compressed package of zookeeper to the linux system.

Note: Alt+P enters SFTP, enter put d:\ zookeeper-3.4.6.tar.gz to upload

Step 3: decompress the package

Tar-zxvf zookeeper-3.4.6.tar.gz

Step 4: go to the zookeeper-3.4.6 directory and create a data folder.

Mkdir data

Step 5: enter the conf directory and rename zoo_sample.cfg to zoo.cfg

Cd confmv zoo_sample.cfg zoo.cfg

Step 6: open zoo.cfg and modify the data attribute: dataDir=/root/zookeeper-3.4.6/data

Zookeeper service startup

Enter the bin directory, start the service and enter the command

. / zkServer.sh start

The following output indicates that the startup is successful

Turn off service input command

. / zkServer.sh stop

Output the following prompt information

View status:

. / zkServer.sh status

If the startup status, prompt

If the status is not started, prompt:

Dubbo native JAR package deployment and installation

The jar package of Dubbo is not deployed to the central warehouse of Maven. You can find the final version of Dubbo in the central warehouse of Maven is 2.5.3. After Alibaba disbanded the Dubbo team, Dangdang continued to maintain the project and renamed it Dubbox. The coordinates remained unchanged and the version changed, but it was not submitted to the central warehouse.

We now need to manually install the jar package for Dubbox into my local repository.

First put the dubbo-2.8.4.jar package to d:\ setup, and then enter the command

Mvn install:install-file-Dfile=d:\ setup\ dubbo-2.8.4.jar-DgroupId=com.alibaba-DartifactId=dubbo-Dversion=2.8.4-Dpackaging=jar

Download URL: https://github.com/dangdangdotcom/dubbox/tree/dubbox-2.8.4

After downloading, decompress it directly. After decompression, cd directly enters dubbo to package maven, and then generates dubbox-2.8.4.jar package in target directory.

Getting started to create Maven Project (WAR) dubboxdemo-service Introduce dependency 4.0.0cn.itcast.dubboxdemodubboxdemo-service0.0.1-SNAPSHOTwar 4.2.4.RELEASE org.springframework spring-context ${spring.version} org.springframework spring-beans ${spring.version} in pom.xml Org.springframework spring-webmvc ${spring.version} org.springframework spring-jdbc ${spring.version} org.springframework spring-aspects ${spring.version} org.springframework Spring-jms ${spring.version} org.springframework spring-context-support ${spring.version} com.alibaba dubbo 2.8.4 org.apache.zookeeper Zookeeper 3.4.6 com.github.sgroschupf zkclient 0.1 javassist javassist 3.11.0.GA org.apache.maven.plugins maven-compiler-plugin 2.3.2 1. 7 1.7 org.apache.tomcat.maven tomcat7-maven-plugin 8081 / create a WEB-INF folder under the webapps of the project Create web.xml contextConfigLocation classpath:applicationContext*.xml org.springframework.web.context.ContextLoaderListener create business interface, create package cn.ldc.org.dubbodemo.service, which is used to store business interface, create interface package cn.ldc.org.dubbodemo.service / * Business Interface * @ author Administrator * * / publicinterface UserService {public String getName ();} create a business implementation class

Create a package cn.ldc.org.dubbodemo.service.impl to hold the business implementation class. Create business implementation class: package cn.ldc.org.dubbodemo.service.impl;import com.alibaba.dubbo.config.annotation.Service;import cn.itcast.dubbodemo.service.UserService;@Servicepublicclass UserServiceImpl implements UserService {public String getName () {return "itcast";}}

Note: Service annotations are different from the original and need to be introduced under the com.alibaba package

Write a configuration file

Create an applicationContext-service.xml under src/main/resources, as follows:

Note: dubbo:annotation is used to scan the @ Service annotation.

Test run tomcat7:run service consumer development

Development steps:

(1) create a Maven project (WAR) dubboxdemo-web, and introduce dependencies into pom.xml, which is the same as the "dubboxdemo-service" project. The difference is to change the running port of the tomcat plug-in to 8082.

(2) create a WEB-INF directory under the webapps directory and create a web.xml

CharacterEncodingFilter org.springframework.web.filter.CharacterEncodingFilter encoding utf-8 forceEncodingtrue CharacterEncodingFilter / * springmvc org.springframework.web.servlet.DispatcherServlet contextConfigLocation classpath:applicationContext-web.xml springmvc *

(3) copy service interface

Copy the cn.ldc.org.dubboxdemo.service package of the "dubboxdemo-service" project and the interface below to the project.

(4) write Controller

Package cn.ldc.org.dubboxdemo.controller;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.ResponseBody;import cn.itcast.dubbodemo.service.UserService;@Controller@RequestMapping ("/ user") publicclass UserController {@ Reference private UserService userService; @ RequestMapping ("/ showName") @ ResponseBody public String showName () {returnuserService.getName () }}

(5) write spring configuration file

Create applicationContext-web.xml under src/main/resources

Test run

Tomcat7:run

After reading the above, do you have any further understanding of Dubbo? If you want to learn more skills or want to know more about it, you are welcome to follow the industry information channel. Thank you for reading.

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