# Send Fanout Event Notifications
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| **Cost to Complete** | Free Tier |
| **Services Used** | [Amazon SNS](https://aws.amazon.com/sns/) [Amazon SQS](https://aws.amazon.com/sqs/) |
| Sending Fanout Event Notifications on AWS Requires an Account | AWS Free Tier includes 1,000,000 publishes for Amazon Simple Notification Service and 1,000,000 requests of Amazon Simple Queue Service. [View AWS Free Tier Details »](https://aws.amazon.com/free/?e=gs21&src=introduction_freetier) [Create a Free Account in Minutes](https://portal.aws.amazon.com/gp/aws/developer/registration/index.html?e=gs21&src=introduction_signup) |
## Overview
In this tutorial, you will implement a fanout messaging scenario using [Amazon Simple Notification Service (SNS)](https://aws.amazon.com/sns/) and [Amazon Simple Queue Service (SQS)](https://aws.amazon.com/sqs/). In this scenario, messages are "pushed" to multiple subscribers, which eliminates the need to periodically check or poll for updates and enables parallel asynchronous processing of the message by the subscribers.
To illustrate this, we will assume that you are developing a cloud-native application that sends an Amazon SNS message to a topic whenever an order is placed on an online store. The Amazon SQS queues that are subscribed to that topic will each receive identical notifications for the new order.
The AWS services you use in this tutorial are within the [AWS Free Tier](https://aws.amazon.com/free/).
## Implementation
### Step 1: Open the Amazon SNS console
1. Launch the AWS Management Console
When you [click here](https://console.aws.amazon.com/console/home), the AWS Management Console will open in a new browser window, so you can keep this step-by-step guide open. When the screen loads, enter your user name and password to get started. Then type **notification** in the search bar and select **Simple Notification Service** to open the service console.
![\[The AWS Management Console.\]](http://docs.aws.amazon.com/hands-on/latest/send-fanout-event-notifications/images/resource-creation-interface.png)
1. Start the Amazon SNS Console
If the SNS console landing page appears, click **Next step**.
![\[The Amazon SNS console.\]](http://docs.aws.amazon.com/hands-on/latest/send-fanout-event-notifications/images/resource-creation-interface-1.png)
### Step 2: Create an Amazon SNS Topic
In this step, you will create an Amazon SNS topic. A topic is a communication channel to send messages and subscribe to notifications. In this example, a sample ecommerce application will push a message to an Amazon SNS topic whenever a new order is placed on the online store.
1. Create an SNS topic
In the Create topic page, type **New-Orders**, in the topic name box, then click **Create topic**.
![\[The resource creation interface.\]](http://docs.aws.amazon.com/hands-on/latest/send-fanout-event-notifications/images/resource-creation-interface-2.png)
1. Verify topic creation
The Topic details page confirms the topic is successfully created.
![\[Amazon SNS dashboard showing details of the "New-Orders" topic with no subscriptions listed and options to create a subscription.\]](http://docs.aws.amazon.com/hands-on/latest/send-fanout-event-notifications/images/dashboard-details-new-orders-topic.png)
### Step 3: Create the Amazon SQS Queues
Now that you have created the topic with Amazon SNS, you will create Amazon SQS queues that will subscribe to the topic.
When you subscribe multiple queues to a topic, each queue receives identical notifications every time a message is pushed to the topic. Services attached to those queues can then process the orders asynchronously and in parallel.
For example, an Amazon EC2 server instance attached to one of the queues could handle the processing or fulfillment of the order, while the other server instance could be attached to a data warehouse for analysis of all orders received.
To keep things simple, we won't actually attach EC2 instances to the queues in this tutorial.
1. Open the Amazon SQS console
[Click here](https://console.aws.amazon.com/sqs) to open the Amazon SQS console in a new browser window. If the SQS landing page appears, click **Get Started Now**. Otherwise, proceed to the next step.
![\[The navigation menu interface for the Amazon SQS console.\]](http://docs.aws.amazon.com/hands-on/latest/send-fanout-event-notifications/images/navigation-menu-interface-console.png)
1. Create Orders-for-Inventory queue
Our first queue will store orders for a fictional Inventory Service that keeps track of products, adding and deleting them as needed from inventory with each order.
On the **Create New Queue** page, enter **Orders-for-Inventory** in the **Queue Name** field. Leave **Standard Queue** selected and click **Quick-Create Queue**.
![\[The resource creation interface.\]](http://docs.aws.amazon.com/hands-on/latest/send-fanout-event-notifications/images/resource-creation-interface-3.png)
1. Create Orders-for-Analytics queue
Your new queue is created and selected in the queue list. Next, you’ll create a second queue to handle order analytics.
Click **Create New Queue **to create another queue to store orders for the Analytics Service.
![\[The resource creation interface.\]](http://docs.aws.amazon.com/hands-on/latest/send-fanout-event-notifications/images/resource-creation-interface-4.png)
1. Enter queue name
Enter **Orders-for-Analytics** in the **Queue Name** field, and click **Quick-Create Queue**.
![\[AWS SQS queue creation interface showing options for "Standard Queue" and "FIFO Queue" with descriptions and examples, and a red arrow pointing to the "Quick-Create Queue" button.\]](http://docs.aws.amazon.com/hands-on/latest/send-fanout-event-notifications/images/queue-creation-interface-options-standard.png)
1. Verify queue creation
The new queue now appears in the queue list.
![\[The interface controls and buttons.\]](http://docs.aws.amazon.com/hands-on/latest/send-fanout-event-notifications/images/interface-controls-buttons.png)
### Step 4: Subscribe the Queues to the Topic
Now that you have created your two Amazon SQS queues, you need to subscribe them to the Amazon SNS topic that broadcasts notifications of new orders.
1. Subscribe the queues
From the list of queues, select the **Orders-for-Inventory** and **Orders-for-Analytics** queues. From **Queue Actions**, select **Subscribe Queues to SNS Topic**.
![\[The resource creation interface.\]](http://docs.aws.amazon.com/hands-on/latest/send-fanout-event-notifications/images/resource-creation-interface-5.png)
1. Select topic
The **Subscribe to a Topic** dialog box is displayed. From the **Choose a Topic** drop-down list, select your **New-Orders** Amazon SNS topic.
Your SNS topic appears in the list because you created it from the same account that you used to create your Amazon SQS queues. If the SNS topic was made by another account, you could subscribe to it by using the Topic ARN. For more details, see the [Amazon SNS documentation](https://docs.aws.amazon.com/sns/latest/dg/SubscribeTopic.html).
Leave the **Topic Region** unchanged, and click **Subscribe**.
![\[The selection interface.\]](http://docs.aws.amazon.com/hands-on/latest/send-fanout-event-notifications/images/selection-interface.png)
1. Confirm subscription
The **Topic Subscription Result** dialog box is displayed. Click **OK**.
![\[Interface element requiring manual review.\]](http://docs.aws.amazon.com/hands-on/latest/send-fanout-event-notifications/images/interface.png)
### Step 5: Publish a Message to the Topic
Your queues are now subscribed to the topic. In this step, you will simulate a new order by having the fictional ecommerce application push a message to the topic with the order details.
1. Open the publish page
In the Amazon SNS console **New Orders** topic details page, click **Publish message**.
![\[The navigation interface.\]](http://docs.aws.amazon.com/hands-on/latest/send-fanout-event-notifications/images/navigation-interface.png)
1. Send the order message
**Publish Message to topic** page appears. In the Subject box, type Order 123-4567890-1234567. In the **Message** field, enter the following text to represent a sample order:
**1 x Widget @ \$129.99 USD 2 x Widget Cables @ \$14.99**
Click **Publish Message**. A confirmation dialog box will appear.
![\[Interface element requiring manual review.\]](http://docs.aws.amazon.com/hands-on/latest/send-fanout-event-notifications/images/interface-1.png)
### Step 6: Verify the Subscription
Once a new message is published, Amazon SNS will deliver that message to every endpoint that is subscribed to the topic. In a fanout scenario like this one, the Amazon SQS queues are the endpoints.
In this step, you will confirm that the queues received the new order notification by viewing the message that the topic sent to the queues.
1. Open queue messages
In the Amazon SQS console, check the box for the **Orders-for-Inventory** queue from the queue list. From the **Queue Action** drop-down, select **View/Delete Messages**.
![\[The navigation interface.\]](http://docs.aws.amazon.com/hands-on/latest/send-fanout-event-notifications/images/navigation-interface-1.png)
1. Start message polling
Click **Start Polling for Messages**.
![\[Interface element requiring manual review.\]](http://docs.aws.amazon.com/hands-on/latest/send-fanout-event-notifications/images/interface-3.png)
1. View message panel
The **View/Delete Messages in Orders-for-Inventory** dialog box appears.
![\[Interface element requiring manual review.\]](http://docs.aws.amazon.com/hands-on/latest/send-fanout-event-notifications/images/send-fanout-event-notifications-caf.png)
1. Check message content
In the Body column, click **More Details**. The **Message Details** box contains a JSON document that contains the subject and message that you published to the topic.
You have confirmed that the **Orders-for-Inventory** queue received the notification of the new order from the **New-Orders** topic.
Click **Close**.
![\[Interface element requiring manual review.\]](http://docs.aws.amazon.com/hands-on/latest/send-fanout-event-notifications/images/qxlacwt-send-fanout-event-notifications.png)
1. Delete message
We'll assume that our fictional Inventory Service has finished processing this message, and that we can now safely delete the message from the queue.
Click **Delete 1 Message**. To confirm, click **Yes, Delete Checked Messages**. Then click **Close**.
1. Verify Orders-for-Analytics queue received notification
Repeat steps 1 through 5 to confirm that the **Orders-for-Analytics** queue also received the notification of the new order.
![\[Interface element requiring manual review.\]](http://docs.aws.amazon.com/hands-on/latest/send-fanout-event-notifications/images/interface-3.png)
### Clean Up Resources
In this step, you will delete the resources you have created for this tutorial, which include the Topic Subscriptions, Topics, and Queues. It is a best practice to delete resources you are no longer using so you don’t incur charges.
1. Delete the topics
Open the Amazon SNS console and click **Topics** in the left navigation pane.
Select the **New-Orders** topic.
Click **Delete** to delete topics.
![\[The navigation menu interface.\]](http://docs.aws.amazon.com/hands-on/latest/send-fanout-event-notifications/images/navigation-menu-interface.png)
1. Confirm deletion
The **Delete** confirmation dialog box appears. Type **delete me** in the dialog box and click **Delete**. The topic, and its subscriptions, are deleted. You can now close the SNS browser window (but don't sign out, as you still need to delete the queues in the SQS console).
![\[Interface element requiring manual review.\]](http://docs.aws.amazon.com/hands-on/latest/send-fanout-event-notifications/images/lvyibin-bfa-interface.png)
1. Delete the queues
In the Amazon SQS console, select the **Orders-for-Inventory** and **Orders-for-Analytics** queues. From **Queue Actions**, select **Delete Queues**.
![\[AWS SQS management console showing two queues selected, with the "Queue Actions" dropdown open and the "Delete Queues" option highlighted.\]](http://docs.aws.amazon.com/hands-on/latest/send-fanout-event-notifications/images/management-console-two-queues-selected.png)
1. Confirm deletion
The **Delete Queues** dialog box is displayed. Click **Yes, Delete 2 Queues**. The queues are deleted.
You can now sign out of the Amazon SQS console.
![\[Confirmation dialog in AWS asking to delete two SQS queues, one containing a message and the other empty, with a highlighted "Yes, Delete 2 Queues" button.\]](http://docs.aws.amazon.com/hands-on/latest/send-fanout-event-notifications/images/confirmation-dialog-asking-delete-two.png)
## Congratulations\$1
You have implemented a fanout scenario using Amazon SNS and Amazon SQS. You are now ready to use Amazon SNS and Amazon SQS together to deliver messages to applications that require immediate notification of an event, or to buffer messages in Amazon SQS queues for other applications to process later.