#aws #route53

Route53 is a highly available, scalable, fully managed and Authoritative DNS, customer can update DNS records, also it is the Domain Registrar.

Record

To manage and route traffic for a domain. Each record has

  • Domain/subdomain
  • Record type: A or AAAA / CNAME / NS
  • Value
  • Routing policy
  • TTL

Record Type

  • A: map a hostname to ipv4
  • AAAA: to ipv6
  • CNAME: to another hostname, target hostname has to have A / AAAA record. CNAME cannot route to root domain name. (not work for example.com) but can work for (www.example.com)
  • NS: Name Servers for Hosted Zone that can response DNS requires to Route53 hosted zone.

Health check

It checks for public resources, and it can check for

  • Monitor endpoint
  • Monitor other health checks
  • Monitor Cloudwatch Alarms (full control), it checks for alarms stats.

Type of hosted zone

Hosted zone is a container of records, that defines how to route traffic to a domain and its subdomain

  • Private: for VPC traffic. For this type, it requires enabling DNS hostname and DNS support on the VPC.
  • Public

Terms

  • CNAME: Point to a hostname. Work for Non-Root domain
  • Alias: Point to a hostname to an AWS resource. Work for Root/Non-Root domain. Cannot set TTL (managed by Route53)
  • TTL: Time to live of a Route53 record, then it will be refreshed
  • Health check: Check for public resources

Routing Policy

  • Simple: No health check, simple routing to the resource.
  • Geoproximity: Shift traffic from one region to another region by increasing bias. The traffic at the place with higher bias will attrack the traffic.
  • Multi values: Routing traffic to multi resources and it can integrate with health check. So it is powerful than simple routing with multi values
  • Failover: Routing to primary/secondary resources, and it will prepare for failover.
  • Geolocation: Routing based on user country/location.
  • Latency: Routing user based on user’s gps, to choose which one is fastest.
  • Weighted routing: Separate traffic into multi parts to multi resources. It is helpful in the case we need traffic migration

Domain Registrar & DNS Service

  • Domain registrar allows us to register our domain (BigDaddy or Route53)
  • DNS Service allows us to manage our DNS record on DNS service. (Route53 as DNS Service Provider)
  • Usually they comes together.