AWS Application Services and Serverless Notes

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Hello Readers,

This is the final part of the 5-part Series on cracking the AWS Solutions Architect - Associate Exam. In this section, We will be covering notes on the topics: Application services like SQS, SES, SNS, SWS, Kinesis, Elastic Transcoder, Cognito, and Lambda. As a bonus, In the end, We will also have some common exam notes.

Click here for part 4 - AWS Route53, VPC, and HA.

I've divided the notes into a 5 part series.

Application Services Notes

SQS Notes

  • A message queuing service, Is used to decouple the infra
  • SQS supports up to 256 KB, over that limit, goes to S3, and points the object ID.
  • Messages retention period - 1 to 14 days max; Default = 4 days
  • Visibility Timeout - Max 12 hours
  • For existing Message queue users(like RabbitMQ etc), If it's hard to rewrite the application for SQS, Then simply use Amazon MQ
  • Two types:
    • Standard; unlimited transactions/second, no same order, maybe delivered twice.
    • FIFO; limited to 300 transactions/second, same order, delivered only once.

SWS Notes

  • Amazon Simple Workflow Service, It’s a task-oriented API.
  • Used in Amazon warehouses. For locating the package and labeling the address on it.
  • If there is a use case that involves human interaction to it, Then SWS is used.
  • Workflow executions can last up to 1 year. Imagine the whole process of ordering a book on amazon to reach your hand - The package workflow can last up to 1 year.
  • SQS Actors
    • Workflow Starters - imagine a website initiating the purchase of a book
    • Deciders - They who controls the flow of activity
    • Activity Workers - Executes the tasks

Elastic Transcoder

  • Media Transcoder in the cloud
  • Convert media files from the source format to various format that fit different devices

Amazon Cognito

  • Web Identity Federation Service
  • Basically allows you to do single sign-on using Facebook, google, etc
  • Two types:
    • User pool - Similar to IAM User.
    • Identity pool - temporary access to a particular AWS Service.


  • Stream data to, easy to load & analyze data
  • 3 types of Kinesis
    • Kinesis Streams - Data persistence up to 24 hours
    • Kinesis Firehose - No Data persistence
      • It can capture, transform, and load streaming data into S3, Redshift, Elasticsearch Service, and Splunk, enabling near real-time analytics
    • Kinesis Analytics (Kinesis Streams + Firehose)

Serverless Notes


  • Run in 2 ways:
    • Event-driven- Runs based on event triggers from S3 bucket/dynamo DB.
    • Compute Service - Runs based on HTTP Req using API gateway/AWS SDK.
  • Pricing is based on the number of requests, RAM and, duration of each request
  • AWS X-Ray Service - Helps you to debug lambda function.
  • Amazon Polly - For text to speech

Types of Lambda triggers:

  • Synchronous triggers
    • Elastic Load Balancing (Application Load Balancer)
    • Amazon Cognito
    • Amazon Lex
    • Amazon Alexa
    • Amazon API Gateway
    • Amazon CloudFront (Lambda@Edge)
    • Amazon Kinesis Data Firehose
  • Asynchronous triggers
    • Amazon Simple Storage Service
    • Amazon Simple Notification Service
    • Amazon Simple Email Service
    • AWS CloudFormation
    • Amazon CloudWatch Logs
    • Amazon CloudWatch Events
    • AWS CodeCommit
    • AWS Config
  • Poll-based triggers
    • Amazon Kinesis
    • Amazon SQS
    • Amazon DynamoDB Streams


image.png Image Credit

Common Exam Notes

  • In CDN, use OAI (Origin access identity) to prevent from accessing S3 directly. You can only access through CDN and not through S3.
  • To move the master account from one AWS Organisations to other AWS Organisations, the following steps needs to be implemented,
    • Removal of all member accounts from AWS Organisations.
    • Delete the old organization.
    • Invite master account of old AWS Organisation as a member account to join the new AWS Organisation.
  • Converting Legacy Database to Amazon DynamoDB will be a heterogenous conversion. Using AWS Schema Conversion Tool is best suited for such conversion along with AWS DMS to transfer data from on-premise to AWS. Using the Amazon S3 bucket will help to save any amount of data in the most cost-effective way before its uploaded to Amazon DynamoDB.
  • AWS Engine Conversion Tool is for homogenous conversion. (you have dynamoDb on-premise and want to move to AWS DynamoDB. Then it might be helpful)

All the best for your exams!

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