Dubbo + Zookeeper Example Project

This is a quick start for Apache Dubbo RPC Framework using Zookeeper as Service Registry Center. We are building a Dubbo provider, which has multiple instances. We are also building a Dubbo consumers which communicates with the Dubbo provider instances.

We use Zookeeper in our Distributed System to insure high availability and performance.

Important: This tutorial focus on Dubbo with Zookeeper. If you just want to learn setting up Dubbo with Spring Boot without Zookeeper and Docker then check out my other repository: https://github.com/dcnis/dubbo-spring-boot-example

Run application with a single command

docker compose up

This will spin up

• zookeeper
• dubbo-admin
• dubbo-provider-1 (3x instances)
• dubbo-consumer-1 (1x instance)

Usage

Use a browser to connect to the dubbo consumer via http://localhost:8090/hello and we will get a response from one of our three dubbo-provider-1 instances.

Documentation

docker-compose-yml

version: "3.8"
services:
  zookeeper:
    container_name: zookeeper
    image: zookeeper:3.4.9
    ports:
      - "2181:2181"
    restart: always
    networks:
      - dubbo-net

  dubbo-provider-1-0:
    container_name: dubbo-provider-1-0
    depends_on:
      - zookeeper
    image: dubbo-provider-1-image
    #restart: always
    ports:
      - "8080:8080"
      - "28880:28880"
    networks:
      - dubbo-net
    environment:
      - dubbo.registry.address=zookeeper://zookeeper:2181

  dubbo-provider-1-1:
    container_name: dubbo-provider-1-1
    depends_on:
      - zookeeper
    image: dubbo-provider-1-image
    #restart: always
    ports:
      - "8081:8080"
      - "28881:28880"
    networks:
      - dubbo-net
    environment:
      - dubbo.registry.address=zookeeper://zookeeper:2181

  dubbo-provider-1-2:
    container_name: dubbo-provider-1-2
    depends_on:
      - zookeeper
    image: dubbo-provider-1-image
    #restart: always
    ports:
      - "8082:8080"
      - "28882:28880"
    networks:
      - dubbo-net
    environment:
      - dubbo.registry.address=zookeeper://zookeeper:2181

  dubbo-consumer-1-0:
    container_name: dubbo-consumer-1-0
    depends_on:
      - zookeeper
      - dubbo-provider-1-0
    image: dubbo-consumer-1-image
    #restart: always
    ports:
      - "8090:8080"
      - "28883:28880"
    networks:
      - dubbo-net

  dubbo-admin:
    image: apache/dubbo-admin
    container_name: dubbo-admin
    ports:
      - "8091:8080"
    networks:
      - dubbo-net
    environment:
      - admin.registry.address=zookeeper://zookeeper:2181
      - admin.config-center=zookeeper://zookeeper:2181
      - admin.metadata-report.address=zookeeper://zookeeper:2181
      - dubbo.admin.root.password=root
    depends_on:
      - zookeeper

networks:
  dubbo-net:
    name: dubbo-net
    driver: bridge

application.properties of dubbo provider

Following configuration will connect the dubbo provider with the zookeeper registry center.

dubbo.application.name=dubbo-provider-1

# in docker-compose.yml our zookeeper docker container is called 'zookeeper'
zookeeper.docker.container.name=zookeeper

dubbo.registry.address=zookeeper://${zookeeper.docker.container.name}:2181

dubbo.registry.client=curator
dubbo.protocol.name=dubbo
dubbo.protocol.port=20880
dubbo.scan.base-packages=de.dcnis.dubbo

application.properties of dubbo consumer

Following configuration will connect the dubbo consumer with the zookeeper registry center.

zookeeper.docker.container.name=zookeeper
dubbo.application.name=dubbo-consumer-1
dubbo.registry.address=zookeeper://${zookeeper.docker.container.name}:2181
dubbo.consumer.timeout=3000

Additional manual instructions

Following commands will help to build docker images, run docker instances from those images and spin up zookeeper gui without docker compose.

Build docker image from Dockerfile for dubbo provider

docker build --no-cache -f dubbo-provider-1.Dockerfile -t dubbo-provider-1-image .

Build docker image from Dockerfile for dubbo consumer

docker build --no-cache -f dubbo-consumer-1.Dockerfile -t dubbo-consumer-1-image .

Spin up dubbo provider instance

Here we spin up an instance of dubbo-provider-1

docker run --name dubbo-provider-1-0 -d -p 8080:8080 -p 28880:28880 --link zkserver:zkserver dubbo-provider-1-image

Spin up dubbo consumer instance

Here we spin up an instance of dubbo-consumer-1

docker run --name dubbo-consumer-1-0 -d -p 8090:8080 -p 28880:28880 --link zkserver:zkserver dubbo-consumer-1-image

Spin up zookeeper as Service Registry Center

docker run --name zookeeper --restart always -d zookeeper:3.4.9

Zookeeper GUI

ZK_DEFAULT_NODE is the IP-address of the zookeeper docker container. How to get the IP-address of a docker container, will be explained below.

docker run -d \
  -p 8086:8080 \
  -e ZK_DEFAULT_NODE=172.17.0.2:2181/ \
  --name zookeeper-gui \
  -t tobilg/zookeeper-webui

How to get IP-address of docker container

docker inspect -f '{{range.NetworkSettings.Networks}}{{.IPAddress}}{{end}}' container_name_or_id

Setting up Load-Balancing with Dubbo Admin

Connect to Dubbo-Admin

http://localhost:8091/

Go to Service Governance -> Load Balance . Here you can create a new Load Balancing rule e.q. Round Robin, Randon or Least Active.