Introduction

Serverless offers the benefit of -

• No Infrastructure Management

• Auto Scaling

• Pay only for the amount one uses

• Highly available and secure

Image Reference: https://www.youtube.com/watch?v=d9Jb1WKCLd8

Common Use cases

• Calling a backend API for Web or Mobile. Amazon API Gateway can be used in such case

• Automate an action, once a file is received in S3 for eg: Create a thumbnail or transform the image after upload

• Amazon SQS can be used to queue up requests and process the requests one by one.

• To process Streaming data with low latency one can use Amazon Kinesis

• Subscribers are notified when there is something to publish for a topic. Amazon SNS can be used for this service.

• Amazon Eventbridge can receive near real-time notifications when data from AWS services changes. It can be used to route events from AWS Services, Custom applications and 3rd party SASS applications.

• Cloudwatch can be used to schedule jobs at specific times of the day

Image Reference: https://www.youtube.com/watch?v=d9Jb1WKCLd8

SQS vs SNS vs EventBridge

SQS -- Simple Queue System

Should be used for Reliable 1 to 1 Async Communication

Image Reference: https://www.youtube.com/watch?v=RoKAEzdcr7k

• Requires polling mechanism to deliver messages.

• Helps decouple sending and receiving applications/service.

• There are standard and FIFO queues.

• FIFO queues preserve order while standard queues are designed for massive scale.

• FIFO queues are exactly-once-processed while standard queues are at least-once-processed which means the same message can arrive in the queue for more than one time.

• Provides constructs like dead-letter queues and poison-pill management. For more info https://aws.amazon.com/sqs/

SNS -- Simple Notification System

Should be used for the publish-subscribe messaging paradigm.

Benefits of SNS --

• Eliminates the need to periodically poll for new information.

• Instant push-based delivery

Use Cases for SNS --

• Event notification, monitoring applications, and time-sensitive information updates.

Upto 24 hrs messages could be persisted

Image Reference: https://www.youtube.com/watch?v=RoKAEzdcr7k

Event bridge

• Similar to SNS but it has messagebus and not topics. The main advantage is its ability to integrate with 3rd party applications

• It is built to not only capture events from AWS but also for third-party applications

• Amazon EventBridge is a service that provides real-time access to changes in data in AWS services, your applications, and software as a service (SaaS) applications without writing code.

• Upto 24hrs messages could be persistent

Image Reference: https://www.youtube.com/watch?v=RoKAEzdcr7k

Head-to-Head Event Bridge vs SNS

• Easy SAAS integration for Event Bridge

• There is an Upper limit(5 targets per rule) for Fanout compared to millions of subscribers for SNS

• Can filter full event body while SNS can only filter on message attribute

• Event Bridge is slower compared to SNS

• Event Bridge is costlier compared to SNS

  

  Image reference: Choosing Events, Queues, Topics, and Streams in Your Serverless Application - AWS Online Tech Talks - YouTube

When to use EventBridge vs X

Image reference: Choosing Events, Queues, Topics, and Streams in Your Serverless Application - AWS Online Tech Talks - YouTube

Summary

If one needs to process millions of messages use SQS

If one needs to monitor and get notified without the need to poll for information use SNS

If one needs to process a large-scale real-time stream of data use Kinesis

If one needs to capture events from 3rd party SAAS application use EventBridge