Microservices Communication with Apache ActiveMQ

Microservice design involves breaking down an application into smaller tasks that can participate. These tasks often need to interact with each other to meet business needs. Apache ActiveMQ is a popular open-source message broker that facilitates asynchronous communication between microservices. Using message queues, ActiveMQ can ensure that messages are reliably exchanged between services, allowing fragmented and scalable microservice communication

Apache ActiveMQ is a messaging-centric middleware that allows receiving applications to communicate with each other by sending messages via queues and topics In a microservice environment, ActiveMQ can enable services to exchange and view messages asynchronously found that loose coupling and scalability.

Components

• Producer: The service that sends the messages to a message broker.
• Consumer: The service that receives the message from the message broker.
• Message Broker (Apache ActiveMQ): The server that can manage the message queues and topics and ensure reliable message delivery.

Working of Microservices Communication with Apache ActiveMQ

Message Production

• The producer service can creates the message and sends it to the specific queue or topic on the ActiveMQ broker.
• The producer does not need to know the details of the consumer services and it can only needs to the know queue or topic name.

Message Queuing

• ActiveMQ can stores the message in the designated queue or topic.
• If consumer service is not available then the ActiveMQ can holds the message until the consumer is ready to receive it and ensuring no message is lost.

Message Consumption

• The Consumer service can listens to the queue or topic.
• when the message arrives and the consumer retrieves and processes it.
• It can allows the consumer to the handle messages at its the own place and improving the system resilience.

Implementation of Microservices Communication with Apache ActiveMQ

Below is the implementation of microservices communication with Apache ActiveMQ.

Step 1: Setup the Apache ActiveMQ

We can download the ActiveMQ from official website and follow the installation process instructions.

Start ActiveMQ:

Write the below command in cmd and start ActiveMQ.

cd apache-activemq-5.3.2/bin
./activemq start

Image reference:

👁 activemqrun-compressed

ActiveMQ Dashboard:

Below is the ActiveMQ Dashboard.

👁 ActiveMQ Dashboard

Create the producer-service

Step 1: Create a new Spring Boot project using Spring Initializr, and add the following dependencies:

• Spring Web
• Apache ActiveMQ
• Spring DevTools
• Lombok

Once the project is created, the folder structure will be like below.

👁 Folder Structure

Step 2: Open the application.properties file and add the ActiveMQ connection properties to the project.

spring.application.name=producer-service

spring.activemq.broker-url=tcp://localhost:61616
spring.activemq.user=admin
spring.activemq.password=admin

Step 3: Create the ActiveMQConfig Configuration class

We will create the configuration class to configure ActiveMQ.

Go to src > org.example.produceservice> config > ActiveMQConfig and put the below code.

Step 4: Create the MessageService class

Go to src > org.example.produceservice> service > MessageService and put the below code.

Step 5: Create the MessageController class

Go to src > org.example.produceservice> controller > MessageController and put the below code.

Step 6: Open the Main Class and write the following code.

Go to src > org.example.produceservice > ProduceServiceApplication and put the below code.

pom.xml:

Step 7: Run the application

Once we run the application, then the project will run at port 8081.

👁 Application Runs

Create the consumer service

Step 1: Create a new Spring Boot project using Spring Initializr, and include the following dependencies:

• Spring Web
• Apache ActiveMQ
• Spring DevTools
• Lombok

Once the project is created, the file structure will be like below.

👁 Project Structure

Step 2: Open the application.properties file and add the ActiveMQ connection properties to the project.

spring.application.name=consumer-service

server.port=8081
spring.activemq.broker-url=tcp://localhost:61616
spring.activemq.user=admin
spring.activemq.password=admin

Step 3: Create the ActiveMQConfig Configuration class

We will create the configuration class to configure ActiveMQ.

Go to src > org.example.consumerservice> config > ActiveMQConfig and put the below code.

Step 4: Create the MessageListener class

We will create the configuration class to listen the ActiveMQ message broker of the application.

Go to src > org.example.consumerservice> listener > MessageListener and put the below code.

Step 5: Open the Main Class and write the following code.

Go to src > org.example.consumerservice > ConsumerServiceApplication and put the below code.

pom.xml:

Step 6: Run the application

Once we run the application, then the project will run at port 8081.

👁 Application Runs

Producer-service endpoint:

POST http:localhost:8080/send?message=HelloActiveMQ

Output:

👁 ActiveMQ testing in Postman

ActiveMQ Queues Dashboard

Below is the ActiveMQ queues dashboard.

👁 ActiveMQ Queues Dashboard

Consumer-service Application log

Below is the image of Consumer-service Application log.

👁 Consumer-service Application log

This project demonstrates the how to microservices communication with the Apache ActiveMQ of the Spring Boot application. The microservice producer-service and consumer-service can establish the communication using the ActiveMQ message broker of the spring application.

Conclusion

In this article, we have covered the main concepts of the microservices communication with Apache ActiveMQ. It includes the roles of the producers, consumers and the message broker. We also demonstrated the practical example to how to set up and use the ActiveMQ for the inter-service communication.

By adapting Apache ActiveMQ for the microservice architecture, we can build the more resilient, scalable and efficient systems, capable of the handling complex communication patterns and high loads.