SNS & SQS - Fan Out Pattern

• SNS allows applications to send time-critical messages to multiple subscribers.

• SQS is a message queue service used by distributed applications to exchange messages through a polling model.

• Using SNS and SQS together, messages can be delivered to applications that require immediate notification of an event, and also persisted in an SQS queue for other applications to process at a later time.

• SNS TOPICS CANNOT SEND MESSAGES TO SQS FIFO QUEUES!

S3 Events to Multiple Queues

• The S3 notification feature enables you to receive notifications when certain events happen in your bucket.

• To enable notifications, you must first add a notification configuration that identifies the events you want Amazon S3 to publish and the destinations where you want Amazon S3 to send the notifications.

• If you want to send the same S3 event to multiple queues, use SQS + SNS Fanout.