📦 Day 26 of #90DaysOfCloud: Exploring SNS, SQS, and CloudWatch in AWS

On Day 26, we dive into three essential services for communication, automation, and monitoring in the AWS ecosystem:

• SNS (Simple Notification Service) – Push-based messaging

• SQS (Simple Queue Service) – Queue-based messaging

• CloudWatch – Monitoring, metrics, logs, and alarms

These tools are key for event-driven architectures, microservices, and automated cloud operations.

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🌐 1. What is Amazon SNS?

Amazon SNS is a fully managed pub/sub messaging service. It enables applications, services, or users to send messages to multiple subscribers via topics.

🔎 Use Cases:

• Sending email/SMS notifications

• Alerting on system health

• Broadcasting messages to multiple endpoints (Lambda, SQS, HTTP, etc.)

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🛠️ Setting up SNS

✅ Step 1: Create an SNS Topic

1. Go to Amazon SNS → Topics → Create topic

2. Choose Standard type

3. Name your topic, e.g., SystemAlerts

4. Click Create topic

✅ Step 2: Add a Subscription

1. Open your topic > Click Create subscription

2. Choose protocol:

   • Email for testing

   • SQS, Lambda, or HTTP for integrations

3. Enter your email address (if email) and create

✅ You’ll receive a confirmation email — click the link to confirm the subscription.

✅ Step 3: Publish a Message

1. Open the topic > Publish message

2. Enter a subject and message body

3. Click Publish

Check your email inbox for the message!

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📩 2. What is Amazon SQS?

Amazon SQS is a fully managed message queue service that enables decoupling and asynchronous communication between microservices.

🔎 Types of Queues:

• Standard Queue: Best-effort ordering, high throughput

• FIFO Queue: Exactly-once processing, ordered delivery

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🛠️ Setting up SQS

✅ Step 1: Create a Queue

1. Go to Amazon SQS → Create Queue

2. Choose Standard or FIFO

3. Name the queue (e.g., MyQueue)

4. Click Create Queue

✅ Step 2: Send a Message

1. Open your queue > Send and receive messages

2. Type a message (e.g., Hello from Day 26)

3. Click Send message

✅ Step 3: Receive and Delete Message

1. In same section, click Poll for messages

2. Click on the message > View > Delete

📝 You can also integrate SQS with SNS to fan out messages.

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📊 3. What is Amazon CloudWatch?

CloudWatch helps you monitor AWS resources like EC2, RDS, Lambda, etc. It collects logs, tracks metrics, sets alarms, and triggers actions automatically.

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🛠️ CloudWatch Hands-on Guide

✅ Step 1: View EC2 Metrics

1. Go to CloudWatch > Metrics

2. Choose EC2 > Per-Instance Metrics

3. Monitor CPUUtilization, NetworkIn/Out, etc.

✅ Step 2: Set Up an Alarm

1. Go to Alarms → Create Alarm

2. Select metric (e.g., EC2 > CPUUtilization)

3. Set threshold (e.g., > 60% for 2 datapoints)

4. Choose action → Send notification via SNS

5. Name and Create alarm

Now when CPU exceeds threshold, you’ll get a notification.

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✅ Step 3: Enable CloudWatch Logs (Optional)

For EC2 (Amazon Linux):

sudo yum install -y awslogs
sudo systemctl start awslogsd
sudo systemctl enable awslogsd.service

Edit the AWS Logs config at:

sudo vim /etc/awslogs/awslogs.conf

Add log group, log stream, and restart the agent.

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💡 Key Differences (SNS vs SQS)

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🧠 Summary

📅 What’s Next?

Tomorrow is Day 27 → We’ll dive into AWS RDS (Relational Database Service):

• Creating and managing RDS instances

• Connecting RDS to EC2

• Backups, snapshots, and failover

• Understanding storage types and pricing

Stay tuned to learn how AWS handles fully managed databases at scale!