SNS: Simple Notification Service

SNS is a fully managed messing service for both application to application (A2A) and application to person (A2P) communication.

• The event producer only sends a message to one SNS topic at a time
• Many event receivers can be created to listen to an SNS topic notification
• Limits:
  • 10,000,000 subscriptions per topic
  • 100,000 topics
• Subscriber types:
  • SQS
  • HTTP / HTTPS (with delivery retries)
  • Lambda
  • Emails
  • Mobile Notifications
  • SMS text messages

SNS integrates with most AWS Services

• AWS Services can send data directly to SNS for generating notifications:
  • CloudWatch (for alarms)
  • Auto Scaling Groups
  • S3 buckets (for events)
  • CloudFormation (for state changes)

How to publish a Topic

• Simple:
  • Create a topic
  • Create a subscription
  • Public to the topic
• Publish directly from an application
  • Create an endpoint in your application
  • Publish to the platform endpoint
  • This works with:
    • Google GCM
    • Apple APNS
    • Amazon ADM

Security

• Encryption:
  • In-flight encryption using HTTPS API
  • At-rest encryption using KMS keys
  • Client-side encryption if the client wants to perform encryption/decryption itself

• Access Controls: IAM policies to regulate access to the SNS API

• SNS Access Policies (similar to S3 Bucket policies)
  • Useful for multi-account access to SNS topics
  • Useful for allowing other services to write to an SNS topic