AWS Route53, VPC, and HA Notes

Subscribe to my newsletter and never miss my upcoming articles

Hello Readers,

This is part 4 of the 5-part Series on cracking the AWS Solutions Architect - Associate Exam. In this section, We will be covering notes on the topics: Route53(DNS), VPC(Virtual Private Cloud), and High-Availability.

Click here for part 3 - AWS Databases.

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

Route53 Notes

Domain-name -> NS -> SOA -> A/CNAME/Alias

  • NS - name server. It tells which server: Awsdns/GoDaddy/Bigrock.
  • SOA - Start of authority, gives information about the alias/A/CNAME
  • A - Address, gives IP address
  • CNAME - canonical name, points to another domain name
    • CNAME cannot be given for naked domain name (apex records) For Ex: the naked domain is; instead, CNAME is for
  • Alias - points to a DNS ( Ex: ALB, CDN, S3 )
  • MX - for mail exchange server
  • PTR - the reverse of A record. Lookup Ip address for the domain name.

Types of DNS Routing

  • Simple Routing
  • Weighted Routing ( you can distribute traffic %; also add health checks)
  • Latency-based Routing
  • Failover Routing
  • Geolocation Routing ( for specific location)
  • GeoProximity Routing (Traffic flow only) (based on physical distance)
  • Multivalue Answer Routing (Simple Routing + health checks)

VPC Notes

  • Disable Source/Destination checks from NAT Instances when configuring.
  • Direct connect - Dedicated connection from local office datacenter to AWS datacenter.
  • Global Acceleration - Let your users access your application via edge location (Superfast) increases availability and performance
    • You are assigned 2 static IP address/ Bring your own
    • You can attach ALB, NLB, or EC2 instance
  • VPC Endpoint - lets you connect your VPC with selected AWS Services without the need for NAT gateway, Internet Gateway, etc. Two types:
    • Interface Endpoint - attached ENI to ec2
    • Gateway Endpoint - Connects with S3, DynamoDB

HA Notes

Autoscaling has 3 components

  • Groups - Logical component grouping
  • Configuration Templates - Groups uses launch template/configuration
  • Scaling Policies
    • Target tracking scaling: Applied to check the ASGAvgCPUUtilization
    • Step Scaling: Adjust the capacity based on step adjustment instead of the target
    • Simple Scaling: Changes the capacity based on a single adjustment
  • Scaling Options - Configure conditions (CPU, memory, schedule, etc). There are 5 options. They are:
    • Maintain current instance levels at all times (ex: min 5 instances always)
    • Scale Manually
    • Scale based on a schedule
    • Scale based on a demand
    • Use predictive scaling

Continue reading Part 5 - AWS Application Services and Serverless Notes ...

No Comments Yet