What is a SNS?

- Amazon Simple Notification Service (SNS) is a web service that makes it easy to setup, operate, and send notifications from the cloud.
- It provides developers with a highly scalable, flexible, and cost-effective capability to publish messages from an application and immediately deliver them to subscribers or other applications.
- Allow Push notifications to Apple, Google, Fire OS, and Windows devices, as well as Android devices in China with Baidu Cloud Push.
- Besides pushing cloud notifications directly to mobile devices, Amazon SNS can also deliver notifications by SMS text messages or email to Amazon SQS queues, or to any HTTP endpoint.
- SNS allows you to group multiple recipients using topics.
- A topic is an 'access point' for allowing recipients to dynamically subscribe for identical copies of the same notification.
- One topic can support deliveries to multiple endpoint types - for example, you can group together iOS, Android and SMS recipients.
- When you publish once to a topic, SNS delivers appropriately formatted copies of your message to each subscriber.
- To prevent messages from being lost, all messages published to Amazon SNS are stored redundantly across multiple AZ.

SNS Benefits

- Instantaneous, push-based delivery (no polling).
- Simple APIs and easy integration with applications.
- Flexible message delivery over multiple transport protocols.
- Inexpensive, pay-as-you-go model with no up-front costs.
- Web-based AWS Management Console offers the simplicity of a point-and-click interface.