RabbitMQ Configuration

Overview

Argos Mesh uses RabbitMQ as the message broker for asynchronous communication between microservices. The system implements a topic-based exchange pattern for flexible routing of events.

Connection Configuration

Basic Connection Settings

spring.rabbitmq.host

string

required

RabbitMQ server hostnameDefault: message_broker (Docker service name)Production: Use FQDN or IP address

spring.rabbitmq.port

number

required

AMQP protocol portDefault: 5672

spring.rabbitmq.username

string

required

Authentication usernameDefault: admin

spring.rabbitmq.password

string

required

Authentication passwordDefault: admin123

Change default credentials in production!

spring.rabbitmq.listener.simple.prefetch

number

Number of messages to prefetch per consumerDefault: 1Purpose: Fair dispatch - each consumer processes one message at a time

Application Properties Example

spring.rabbitmq.host=message_broker
spring.rabbitmq.port=5672
spring.rabbitmq.username=admin
spring.rabbitmq.password=admin123
spring.rabbitmq.listener.simple.prefetch=1

Queue and Exchange Architecture

Orders Service Queues

The Orders service publishes events related to sales and product management.

argos.sales.queue

Queue

Queue Name: argos.sales.queueDurability: true (survives broker restart)Purpose: Receives sales transaction eventsExchange: shop.exchangeRouting Key: shop.event.sold

argos.products.mgmt.queue

Queue

Queue Name: argos.products.mgmt.queueDurability: truePurpose: Receives product lifecycle events (created, updated, deleted)Exchange: shop.exchangeRouting Key: shop.event.product.# (wildcard)

Configuration Code

orders/config/RabbitMQConfig.java

@Configuration
public class RabbitMQConfig {

    public static final String QUEUE_SALE = "argos.sales.queue";
    public static final String QUEUE_PRODUCTS = "argos.products.mgmt.queue";
    
    public static final String EXCHANGE_NAME = "shop.exchange";
    public static final String RK_SALES = "shop.event.sold";
    public static final String RK_PRODUCTS = "shop.event.product.#";

    @Bean
    public Queue salesQueue() {
        return new Queue(QUEUE_SALE, true);
    }

    @Bean
    public Queue productsQueue() {
        return new Queue(QUEUE_PRODUCTS, true);
    }

    @Bean
    public TopicExchange exchange() {
        return new TopicExchange(EXCHANGE_NAME);
    }

    @Bean
    public Binding bindingSales(Queue salesQueue, TopicExchange exchange) {
        return BindingBuilder.bind(salesQueue).to(exchange).with(RK_SALES);
    }

    @Bean
    public Binding bindingProducts(Queue productsQueue, TopicExchange exchange) {
        return BindingBuilder.bind(productsQueue).to(exchange).with(RK_PRODUCTS);
    }
}

Sentinel Service Queues

The Sentinel service consumes events for monitoring and alert generation.

argos.sales.queue

Queue

Queue Name: argos.sales.queueDurability: truePurpose: Monitors sales for rate limiting analysisExchange: shop.exchangeRouting Key: shop.event.sold

argos.alert.queue

Queue

Queue Name: argos.alert.queueDurability: truePurpose: Publishes security alerts when suspicious activity is detectedExchange: alert.exchangeRouting Key: argos.alert.# (wildcard)

Configuration Code

sentinel/config/RabbitMQConfig.java

@Configuration
public class RabbitMQConfig {
    public static final String QUEUE_ALERT = "argos.alert.queue";
    public static final String ALERT_EXCHANGE = "alert.exchange";
    public static final String RK_ALERT = "argos.alert.#";

    public static final String QUEUE_SALE = "argos.sales.queue";    
    public static final String EXCHANGE_SOLD = "shop.exchange";
    public static final String RK_SALES = "shop.event.sold";

    // Notifications queue
    @Bean
    public Queue alertQueue() {
        return new Queue(QUEUE_ALERT, true);
    }

    @Bean
    public TopicExchange exchange() {
        return new TopicExchange(ALERT_EXCHANGE);
    }

    @Bean
    public Binding binding(Queue alertQueue, TopicExchange exchange) {
        return BindingBuilder.bind(alertQueue).to(exchange).with(RK_ALERT);
    }

    // Sales queue
    @Bean
    public Queue salesQueue() {
        return new Queue(QUEUE_SALE, true);
    }

    @Bean
    public TopicExchange exchangeSold() {
        return new TopicExchange(EXCHANGE_SOLD);
    }

    @Bean
    public Binding bindingSales(Queue salesQueue, TopicExchange exchange) {
        return BindingBuilder.bind(salesQueue).to(exchange).with(RK_SALES);
    }
}

Notify Service Queues

The Notify service consumes alert events for notification delivery.

argos.alert.queue

Queue

Queue Name: argos.alert.queueDurability: truePurpose: Consumes alerts and sends notificationsExchange: alert.exchangeRouting Key: argos.alert.# (wildcard)

Configuration Code

notify/config/RabbitMQConfig.java

@Configuration
public class RabbitMQConfig {

    public static final String QUEUE_ALERT = "argos.alert.queue";
    public static final String ALERT_EXCHANGE = "alert.exchange";
    public static final String RK_ALERT = "argos.alert.#";

    @Bean
    public Queue alertQueue() {
        return new Queue(QUEUE_ALERT, true);
    }

    @Bean
    public TopicExchange exchange() {
        return new TopicExchange(ALERT_EXCHANGE);
    }

    @Bean
    public Binding binding(Queue alertQueue, TopicExchange exchange) {
        return BindingBuilder.bind(alertQueue).to(exchange).with(RK_ALERT);
    }
}

Message Serialization

All services use Jackson JSON for message serialization with custom configuration:

RabbitMQConfig.java

@Bean
public ObjectMapper objectMapper() {
    ObjectMapper mapper = new ObjectMapper();
    mapper.registerModule(new JavaTimeModule());
    mapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
    return mapper;
}

@Bean
public MessageConverter jsonMessageConverter(ObjectMapper objectMapper) {
    return new Jackson2JsonMessageConverter(objectMapper);
}

The JavaTimeModule enables proper serialization of Java 8+ date/time types (LocalDateTime, Instant, etc.) without timestamps.

Routing Patterns

Topic Exchange Routing

Argos Mesh uses Topic Exchanges for flexible message routing:

Routing Key	Pattern	Queue	Purpose
`shop.event.sold`	Exact match	`argos.sales.queue`	Sales transactions
`shop.event.product.#`	Wildcard	`argos.products.mgmt.queue`	Product events
`argos.alert.#`	Wildcard	`argos.alert.queue`	Security alerts

Wildcard Routing Explained

Hash (#) Wildcard: Matches zero or more wordsExamples:

shop.event.product.# matches:
- shop.event.product.created
- shop.event.product.updated
- shop.event.product.deleted

Star (*) Wildcard: Matches exactly one wordExample:

shop.event.* matches:
- shop.event.sold
- shop.event.created
But NOT shop.event.product.created

Queue Durability

All queues are marked as durable (true), which means:

Queues survive RabbitMQ broker restarts
Messages are not lost on broker failure (when marked as persistent)
Suitable for production environments

Non-durable queues are deleted when the broker restarts.

Prefetch Count

Setting prefetch=1 ensures fair dispatch:

RabbitMQ won’t give more than one message to a worker at a time
Prevents fast workers from being idle while slow workers are overloaded
Messages are distributed evenly across consumers

This is critical for the Sentinel service which performs intensive analysis.

Docker Configuration

RabbitMQ runs as a Docker container with the management plugin enabled:

docker-compose.yml

rabbitmq:
  image: rabbitmq:3-management-alpine
  container_name: message_broker
  ports:
    - "5672:5672"   # AMQP protocol
    - "15672:15672" # Management UI
  environment:
    - RABBITMQ_DEFAULT_USER=admin
    - RABBITMQ_DEFAULT_PASS=admin123
  healthcheck:
    test: ["CMD", "rabbitmq-diagnostics", "-q", "ping"]
    interval: 10s
    timeout: 5s
    retries: 3
  networks:
    - argos-network

Management UI

Access the RabbitMQ Management UI at http://localhost:15672 Default Credentials:

Username: admin
Password: admin123

Change these credentials for production deployments!

Monitoring and Management

View Queues

Monitor queue depth, consumer count, and message rates in the Management UI

Check Bindings

Verify exchange-to-queue bindings and routing key patterns

Message Tracing

Enable tracing to debug message routing issues

Performance Metrics

Track message publish/delivery rates and memory usage

Troubleshooting

Connection Refused

Symptoms: Services fail to start with connection errorsSolutions:

Verify RabbitMQ container is running: docker ps
Check health status: docker logs message_broker
Ensure port 5672 is accessible
Verify network connectivity between containers

Messages Not Being Consumed

Symptoms: Messages accumulate in queuesSolutions:

Check consumer count in Management UI
Verify listeners are registered: check application logs
Ensure @RabbitListener annotations are present
Check for exceptions in consumer methods

Routing Issues

Symptoms: Messages sent but not receivedSolutions:

Verify routing key matches binding pattern
Check exchange type (Topic vs Direct)
Use Management UI to trace message flow
Verify queue bindings are correct

Getting Started

Configuration

RabbitMQ Configuration

Overview

Connection Configuration

Basic Connection Settings

Application Properties Example

Queue and Exchange Architecture

Orders Service Queues

Configuration Code

Sentinel Service Queues

Configuration Code

Notify Service Queues

Configuration Code

Message Serialization

Routing Patterns

Topic Exchange Routing

Docker Configuration

Management UI

Monitoring and Management

View Queues

Check Bindings

Message Tracing

Performance Metrics

Troubleshooting

Build docs developers (and LLMs) love

Getting Started

Configuration

​Overview

​Connection Configuration

​Basic Connection Settings

​Application Properties Example

​Queue and Exchange Architecture

​Orders Service Queues

​Configuration Code

​Sentinel Service Queues

​Configuration Code

​Notify Service Queues

​Configuration Code

​Message Serialization

​Routing Patterns

​Topic Exchange Routing

​Docker Configuration

​Management UI

​Monitoring and Management

View Queues

Check Bindings

Message Tracing

Performance Metrics

​Troubleshooting

Build docs developers (and LLMs) love

Overview

Connection Configuration

Basic Connection Settings

Application Properties Example

Queue and Exchange Architecture

Orders Service Queues

Configuration Code

Sentinel Service Queues

Configuration Code

Notify Service Queues

Configuration Code

Message Serialization

Routing Patterns

Topic Exchange Routing

Docker Configuration

Management UI

Monitoring and Management

Troubleshooting