Configure Amazon SNS Notifications with Amazon SQS

Purpose of This Lesson

This hands-on lesson demonstrates how to publish a message to an Amazon Simple Notification Service (Amazon SNS) standard topic and deliver that message to an Amazon Simple Queue Service (Amazon SQS) standard queue. It also illustrates how SNS-to-SQS fan-out can distribute the same notification to multiple queues for independent processing.

Key Concepts

• Amazon SNS topic: The publisher-facing destination that receives messages and forwards them to subscribed endpoints.
• Publisher: The application, service, or operator that sends a message to an SNS topic.
• Subscriber: An endpoint that receives messages published to the topic. The lesson uses an SQS queue as the subscriber and notes that email is another possible endpoint.
• Amazon SQS queue: A durable consumer endpoint that stores messages so they can be polled and processed later.
• Standard topic and standard queue: The lab uses both standard SNS and standard SQS resources.
• Confirmed subscription: The SNS-to-SQS relationship must exist and be confirmed before messages can be delivered to the queue.
• Fan-out: One SNS message can be delivered to multiple subscribed SQS queues. Each queue can then be processed independently, potentially by different processors, functions, or instances.
• Resource-based policies: The SNS topic and SQS queue configuration screens expose access-policy settings. These policies are part of the permission model for resource access.

SNS-to-SQS Configuration and Verification

1. Create the SNS topic

1. Open the Amazon SNS console and select Topics.
2. Create a new topic.
3. Choose the Standard topic type.
4. Provide a topic name, such as my-sqs-test.
5. Leave the other settings at their defaults for this lab, including the access policy and encryption settings.
6. Create the topic.

An SNS topic by itself does not provide a destination for delivered messages. It requires one or more subscriptions.

2. Create the SQS queue

1. Open the Amazon SQS console.
2. Create a new queue.
3. Choose a Standard queue.
4. Provide a queue name, such as my-queue.
5. Leave the remaining settings at their defaults for this exercise.
6. Create the queue.

3. Subscribe the queue to the topic

The lesson demonstrates subscribing from the SQS side:

1. Open the SQS subscription option.
2. Select the existing SNS topic as the resource.
3. Choose the topic created for the lab, such as my-sqs-test.
4. Save the subscription.
5. Refresh the SNS topic view and confirm that the subscription is shown as Confirmed.

The console also provides an SNS-side subscription wizard. The important result is the same: the SQS queue must be associated with the SNS topic and show a confirmed subscription.

4. Publish and retrieve a test message

1. Open the SNS topic and choose the option to publish a message.
2. Enter a subject such as send message to SQS.
3. Enter a message body such as hello from SNS.
4. Publish the message.
5. Open the SQS queue and choose Send and receive messages.
6. Poll for messages.
7. Open the received message and verify that both the subject and message body are present.

This test confirms the complete path: SNS publication, subscription delivery, SQS queue storage, and queue polling.

Exam- or Assessment-Relevant Takeaways

• SNS is a publisher/subscriber service; publishing to a topic does not deliver anything unless the topic has a subscriber.
• Use an SQS subscription when a message should be queued for later polling and processing rather than delivered directly to an endpoint such as email.
• A confirmed SNS subscription is an important verification point when troubleshooting delivery.
• The SNS-to-SQS pattern supports fan-out: one SNS publication can be delivered to multiple SQS queues.
• Multiple queues allow independent consumers to process the same notification differently, such as using separate processors, functions, or instances.
• The lab uses a standard SNS topic and a standard SQS queue; do not infer FIFO ordering or deduplication behavior from this exercise.
• Console validation should include both publishing a test message and polling the queue to verify receipt.

Tool / Feature Decision Guide

Requirement	Appropriate choice in this lesson	Reason
Send a notification to a simple endpoint	SNS with an email subscription	Email is presented as a straightforward SNS subscriber option, subject to endpoint confirmation.
Queue a notification for later processing	SNS with an SQS subscription	SQS stores the delivered message for consumers to poll and process.
Send the same notification to separate processing pipelines	One SNS topic with multiple SQS subscriptions	SNS fan-out delivers the message to each subscribed queue.
Validate an SNS-to-SQS integration	Publish a test message, then poll the queue	This verifies both delivery and queue-side visibility.
Investigate a missing delivery	Check that the queue subscription exists and is confirmed	An SNS topic without a valid subscriber has no configured destination for delivery.

Common Traps / Misconceptions

• Creating a topic is not enough: A topic needs one or more subscriptions before published information has a destination.
• Confusing SNS and SQS roles: SNS receives and distributes published messages; SQS queues and exposes messages for consumers to poll.
• Skipping subscription verification: Always confirm that the SNS-to-SQS subscription appears as confirmed before testing delivery.
• Assuming one queue limits delivery to one consumer workflow: Multiple queues can subscribe to the same SNS topic, enabling fan-out to independent processing paths.
• Treating a standard queue as an ordered or exactly-once system: The lab only establishes standard SNS and standard SQS usage and does not demonstrate FIFO guarantees.
• Failing to poll the queue: Publishing successfully to SNS does not by itself prove that the SQS subscription and delivery path work.
• Overlooking access policies: Both SNS and SQS expose resource-based policy settings. Leaving defaults unchanged is suitable for this lab, but production integrations still require appropriate permissions.

Real-World Engineer / Analyst Notes

• Design the SNS topic as the distribution point and the SQS queues as independently controlled consumer pipelines.
• Use separate queues when different processors need to receive the same event but handle it with different logic, workloads, or ownership boundaries.
• Test integrations end to end instead of validating only that the SNS topic exists. A successful test includes publication, queue delivery, polling, and inspection of the message contents.
• Treat the subscription state as a first troubleshooting checkpoint. A topic can accept publications even when the intended downstream subscription is missing or not confirmed.
• The lab leaves encryption and access-policy settings at their defaults; real deployments should evaluate these settings against the required security and access model.

Quick Reference Summary

• Create a standard SNS topic.
• Create a standard SQS queue.
• Subscribe the queue to the SNS topic.
• Verify that the subscription is Confirmed.
• Publish a test message containing a subject and body.
• Poll the SQS queue and inspect the received message.
• Use multiple SQS subscriptions for SNS fan-out to independent consumers.

Flashcards

Q: A team publishes notifications to an SNS topic, but no downstream system receives them. What is the first architectural issue to check?
A: Check whether the topic has a valid, confirmed subscription. An SNS topic requires subscribers before it has configured delivery destinations.

Q: When should you use an SNS-to-SQS subscription instead of an email subscription?
A: Use SNS-to-SQS when a consumer needs messages queued for later polling and processing. Email is better suited to direct notification delivery to an email endpoint.

Q: What does SNS do and what does SQS do in the lab’s message path?
A: SNS accepts the published message and distributes it to subscribers. SQS stores the delivered message in a queue so a consumer can poll and process it.

Q: You need the same SNS notification handled by two independent processing systems. Which topology should you choose?
A: Subscribe two separate SQS queues to the SNS topic. SNS fan-out delivers the message to both queues, allowing independent processing.

Q: What console state confirms that the SNS topic and SQS queue are connected for delivery?
A: The SNS-to-SQS subscription should appear as Confirmed.

Q: How do you verify end-to-end delivery from SNS to SQS?
A: Publish a test message to the SNS topic, open the SQS queue, poll for messages, and inspect the received subject and message body.

Q: What is the difference between publishing to an SNS topic and polling an SQS queue?
A: Publishing places a message into the SNS distribution workflow. Polling retrieves messages that have been delivered into an SQS queue.

Q: What is the main benefit of SNS fan-out to multiple SQS queues?
A: Each queue can support a separate consumer workflow, such as different processors, functions, instances, or customer-specific handling.

Q: Which resource types are used in this lab?
A: The lab uses an SNS standard topic and an SQS standard queue.

Q: A message is visible in SNS publication history or appears to publish successfully, but the queue is empty. What should you verify?
A: Verify that the intended SQS queue is subscribed to the correct SNS topic and that the subscription is confirmed. Then poll the queue again.

Q: What message fields are inspected during the lab’s SQS verification step?
A: The received message is checked for the SNS publication’s subject and message body.

Q: Why might an organization create multiple SQS queues for one SNS topic?
A: Different queues can route the same notification to different processing logic, operational teams, functions, instances, or customer workflows.

Q: What configuration areas are exposed when creating the SNS topic and SQS queue?
A: The consoles expose settings including resource-based access policies and encryption options, although the lab leaves them at their defaults.

Practice Questions

Question 1

An operations team wants one alert publication to be processed by two independent consumers. Consumer A transforms the data, while Consumer B stores it for a different workflow. Which design best matches the lab’s pattern?

A. Publish directly to only Consumer A and have it forward the message to Consumer B
B. Create one SNS topic with an SQS subscription for each consumer
C. Create two SNS topics and publish to only one of them
D. Place the message directly into one SQS queue and have both consumers poll it

Correct answer: B

Explanation: Multiple SQS subscriptions to one SNS topic provide fan-out, allowing each consumer workflow to receive and process its own queue copy independently.

Question 2

A newly created SNS topic accepts a test publication, but no SQS message appears. The SQS queue exists and can be polled. Which check is most directly relevant first?

A. Whether the topic has a confirmed subscription to that queue
B. Whether the queue was created as a FIFO queue
C. Whether an email endpoint confirmed the message
D. Whether the SNS topic has more than one publisher

Correct answer: A

Explanation: The delivery path requires a valid SNS-to-SQS subscription, and the lesson specifically verifies that the subscription is confirmed.

Question 3

An engineer needs a message endpoint that can retain notifications until a consumer polls and processes them. Which service should be used as the SNS subscriber?

A. Amazon SQS
B. Amazon SNS only, without a subscription
C. An additional SNS topic with no endpoint
D. An email address, because it provides queue polling

Correct answer: A

Explanation: SQS provides the queueing endpoint in this architecture, while SNS performs publication and distribution.

Question 4

During validation, a message is published to the SNS topic. What sequence best confirms that the SNS-to-SQS integration worked?

A. Create another topic and wait for automatic replication
B. Open the queue, poll for messages, and inspect the subject and body
C. Delete and recreate the queue without polling
D. Check only that the SNS topic exists

Correct answer: B

Explanation: Polling the queue and inspecting the received message verifies delivery and confirms that the expected publication content reached SQS.

WordPress Metadata

Suggested Slug:
configure-sns-notifications-with-sqs

Meta Description:
Learn how to connect an Amazon SNS standard topic to an Amazon SQS standard queue, publish messages, verify delivery, and use fan-out processing patterns.

Tags:
AWS, Amazon SNS, Amazon SQS, CloudWatch Monitoring, Messaging, Pub/Sub, Fan-Out Architecture, Standard Topics, Standard Queues, Cloud Operations