Lab Goal

You will build this flow:

SNS Topic (publisher) → SQS Queue (subscriber) → receive message

Why this matters:

• SNS = “broadcast / publish” messages
• SQS = “store messages safely until processed”
• Together = decoupled microservices (production pattern)

Step-by-step Lab (Console)

Step 0: Open AWS Console

1. Login to AWS Console
2. Make sure you are in a region (example: us-east-2 Ohio)

• Top-right corner → choose region

Part A — Create SNS Topic

Step 1: Open SNS

1. In AWS Console search bar, type: SNS
2. Click Simple Notification Service

Step 2: Create a Topic

1. Left menu → click Topics
2. Click Create topic

Step 3: Configure Topic

1. Type: select Standard
2. Name: devops-sns-topic
3. Scroll down (leave defaults)
4. Click Create topic

Step 4: Copy the Topic ARN

1. After creation, you will be inside the topic page
2. Find ARN (looks like arn:aws:sns:...)
3. Copy it and save it in notes:

• SNS_TOPIC_ARN = ...

Part B — Create SQS Queue

Step 5: Open SQS

1. In AWS Console search bar, type: SQS
2. Click Simple Queue Service

Step 6: Create Queue

1. Click Create queue

Step 7: Configure Queue

1. Type: select Standard
2. Name: devops-sqs-queue
3. Leave the defaults for beginner lab
4. Scroll down → click Create queue

Step 8: Copy Queue ARN + Queue URL

1. Open your queue: click devops-sqs-queue
2. Copy and save:

• ARN (save as SQS_QUEUE_ARN = ...)
• URL (save as SQS_QUEUE_URL = ...)

Part C — Subscribe SQS to SNS

Step 9: Go back to SNS Topic

1. Search SNS again (or open from services)
2. Click Topics
3. Click devops-sns-topic

Step 10: Create Subscription

1. Scroll to Subscriptions
2. Click Create subscription

Step 11: Subscription settings

1. Topic ARN should already be filled
2. Protocol: choose Amazon SQS
3. Endpoint: paste your SQS queue ARN

• paste SQS_QUEUE_ARN
  1. Click Create subscription

Part D — Allow SNS to send messages into SQS (VERY IMPORTANT)

If you skip this, messages often won’t arrive.

Step 12: Open SQS queue permissions

1. Go to SQS
2. Click Queues
3. Click devops-sqs-queue

Step 13: Edit Access Policy

1. Go to Access policy (or “Permissions” tab)
2. Click Edit
3. You will see a policy JSON box

Step 14: Paste policy (and replace values)

Paste this policy:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "Allow-SNS-SendMessage",
      "Effect": "Allow",
      "Principal": { "Service": "sns.amazonaws.com" },
      "Action": "sqs:SendMessage",
      "Resource": "SQS_QUEUE_ARN",
      "Condition": {
        "ArnEquals": {
          "aws:SourceArn": "SNS_TOPIC_ARN"
        }
      }
    }
  ]
}

Now replace:

• SQS_QUEUE_ARN → your real queue ARN
• SNS_TOPIC_ARN → your real topic ARN

Click Save changes

Part E — Publish a message to SNS

Step 15: Go to SNS Topic again

1. Open SNS
2. Topics → click devops-sns-topic

Step 16: Publish message

1. Click Publish message
2. Subject (optional): test-message
3. Message body:

   Hello students!
   SNS published this message.
   SQS will store it until consumer reads it.

1. Click Publish message

Part F — Receive the message from SQS

Step 17: Open queue to read messages

1. Open SQS
2. Click devops-sqs-queue

Step 18: Poll for messages

1. Click Send and receive messages
2. Click Poll for messages
3. You should see the message appear

Step 19: View message body

1. Click the message
2. Expand details
3. You will see SNS wrapped the message (normal behavior)

Step 20: Delete message

1. Select the message checkbox
2. Click Delete
3. Confirm delete

What should learn

SNS (Topic)

• “I send 1 message”
• “Many systems can receive it”
• Like: announcements to many subscribers

SQS (Queue)

• “I store messages safely”
• “Consumer reads later”
• Prevents loss if consumer is down

Together

• Producer and consumer do not depend on each other
• More reliable and scalable systems

Common mistakes (quick troubleshooting)

1) No messages arrive in SQS

Check:

• Did you add SQS access policy allowing SNS?
• Did you paste the correct topic ARN in the policy?
• Are SNS + SQS in the same AWS region?

2) Subscription looks fine but still nothing

• Re-open subscription → confirm it’s using correct queue ARN
• Re-publish message

Cleanup (optional but good practice)

• Delete subscription (SNS topic → Subscriptions → delete)
• Delete SNS topic
• Delete SQS queue