Active MQ

📨 What is Amazon MQ?

Amazon MQ is a managed message broker service for Apache ActiveMQ and RabbitMQ that makes it easy to set up and operate messaging systems in the cloud without managing infrastructure.

✅ Use it when migrating existing message-based applications that rely on standard protocols like AMQP, MQTT, STOMP, OpenWire, JMS, or WebSocket.

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🧠 Key Concepts

Concept	Description
Message Broker	Software that enables apps to communicate via queues and topics asynchronously
Amazon MQ Broker	A fully managed ActiveMQ or RabbitMQ instance
Queue / Topic	Destination type where messages are delivered (point-to-point or publish-subscribe)
Persistent Storage	Messages are stored until consumed
Security Groups	Control access to the broker endpoint

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🚀 Supported Engines

Engine	Description
ActiveMQ	Ideal for traditional JMS apps, supports durable queues/topics, transactions
RabbitMQ	More lightweight, plugin-friendly, widely used in microservices

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🛠️ Common Use Cases

Use Case	Why Amazon MQ?
🧳 Legacy enterprise migration	Lift-and-shift existing JMS/RabbitMQ apps
🔄 Application decoupling	Queues and topics help microservices communicate
🔁 Publish-subscribe workflows	Topics with multiple subscribers
🛂 Reliable inter-service comms	Persistent, ordered, guaranteed delivery

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🧰 Amazon MQ vs Alternatives

Feature	Amazon MQ	SQS	Kinesis
Protocol Support	AMQP, MQTT, JMS, STOMP, etc.	AWS SDK only	AWS SDK only
Message Size	Up to 100 MB	256 KB max	1 MB
Ordering	FIFO	FIFO queue available	Per partition key
Retention	Until acknowledged	Configurable (up to 14 days)	24h–7d
Best for	Legacy MQ apps	Event queueing, background jobs	Stream processing

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🔐 Security Features

Feature	Support
IAM for API	✅ Create/delete brokers
VPC	✅ Deployed within your private subnets
TLS Encryption	✅ TLS enforced endpoints
Authentication	✅ Basic Auth (user/password)
Logging	✅ CloudWatch logs for broker events
KMS Encryption	✅ Optional for message storage

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🔧 Terraform Example – Amazon MQ with ActiveMQ

1. Create a Security Group for the Broker

resource "aws_security_group" "mq_sg" {
  name        = "amazon-mq-sg"
  description = "Allow access to MQ"
  vpc_id      = "vpc-xxxxxxxx"  # replace with your VPC ID

  ingress {
    protocol    = "tcp"
    from_port   = 61617
    to_port     = 61617
    cidr_blocks = ["10.0.0.0/16"]  # limit to app subnets
  }

  egress {
    from_port   = 0
    to_port     = 0
    protocol    = "-1"
    cidr_blocks = ["0.0.0.0/0"]
  }
}

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2. Create the Amazon MQ Broker (ActiveMQ)

resource "aws_mq_broker" "mq" {
  broker_name = "my-activemq-broker"
  engine_type = "ActiveMQ"
  engine_version = "5.17.6"  # or latest
  deployment_mode = "SINGLE_INSTANCE"
  host_instance_type = "mq.t3.micro"

  publicly_accessible = false
  security_groups     = [aws_security_group.mq_sg.id]
  subnet_ids          = ["subnet-xxxxxx"]  # Replace with your private subnet

  user {
    username = "admin"
    password = "YourStrongPassword123!"  # Store securely with TF vars
  }

  logs {
    general = true
  }

  maintenance_window_start_time {
    day_of_week = "Monday"
    time_of_day = "02:00"
    time_zone   = "UTC"
  }
}

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📊 Monitoring with CloudWatch

Metric	Description
CurrentConnections	Active client connections
QueueSize	Messages in a queue
StorePercentUsage	Broker disk utilization
MemoryPercentUsage	Heap usage (especially for ActiveMQ)
EnqueueCount	Number of messages added to queue/topic

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🧪 Message Flow Example

1. Producer (e.g., Spring Boot app with JMS) connects to ActiveMQ via TCP.

2. Sends a message to a queue/topic.

3. Amazon MQ stores the message reliably.

4. Consumer retrieves and processes the message.

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🔧 Connecting App to Amazon MQ (Java Example)

ActiveMQConnectionFactory factory = new ActiveMQConnectionFactory(
    "ssl://b-xxx.mq.us-east-1.amazonaws.com:61617"
);
factory.setUserName("admin");
factory.setPassword("YourStrongPassword123!");
Connection connection = factory.createConnection();

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💰 Pricing (as of 2024)

Resource	Cost
Broker Instance (t3.micro)	~~$0.04/hour (~~$30/month)
Storage	$0.10/GB/month
Data Transfer	Free inbound, standard outbound rates apply
No charge for idle	❌ Charges apply even if no messages

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✅ TL;DR Summary

Feature	Amazon MQ
Managed Message Broker	✅ Supports ActiveMQ and RabbitMQ
Use case	Legacy JMS apps, enterprise queuing, pub-sub
Protocols	AMQP, STOMP, MQTT, JMS, OpenWire, WebSocket
Message Durability	✅ Persistent + durable
Autoscaling	❌ Manual sizing (via instance type)
Terraform Support	✅ aws_mq_broker, aws_security_group

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