Route 53

Route-53 viblo.asia | DNS's FAQ | FAQs | Routing policy |

Overview

when user enter a domain

• Can be used to manage both public and private domain.

• user can access app using these domain name.

• provice health check for resources -> route traffic away from unhealthy resouces.

• Route53 responses to DNS queries.

Benefits

• Performance

  • Low query latency for end-user

  • Low update latency for DNS record management

• Scalable

  • Can handle large query volume.

• Flexibility

  • Route policy

Record types

• CNAME:

  • point host name to another hostname. ex: app.mydomain.com -> blabla.anything.com

  • ONLY FOR NON ROOT domain. ex: aka.sth.mydomain.com

• Alias (A or AAAA)

  • free

  • point a host name to ONLY ONE AWS resource.

    • ex: app.mydomain.com -> blabla.amazonaws.com

  • work for both ROOT and NON-ROOT domain.

  • Always of type A or AAAA

    • A: IPv4

    • AAAA: IPv6

• NS: Name Server for Hosted Zone

• MX: mail exchange record

-	CNAME	ALIAS
Target group	point to the host	point to AWS resources
Target group value	DNS or Hostname	DNS
Response	return DNS/Hostname. Need to query Alias to know the IP	A or AAAA
$	Yes	No
TTL	Yes	No
Root domain	No	Yes

Features

Hosted Zone

• Public: how traffic is routed in the internet.

• Private: determine how traffic is routed within VPC

Weighted routing policy

Weighted routing policy

• Weighted: eg 5% traffic go to production environment.

  • Sum of total weighted % is not neccessary 100%

  • DNS record need to be same type, same domain or subdomain.

  • If you set weight = 0 for all records, the traffic will be balanced for all.

• Latency: evaluate the latency between your users & AWS regions, to minimize the latency.

• Use cases:

  • Load balancing

  • Testing new software version.

Latency Routing

• Letting Route 53 serve user requests from the AWS Region that provides the lowest latency.

• Use case: improve performance / reduce latency.

Geolocation Routing

Lets you choose the instances that will serve traffic based on the location of your users

For example: US -> instance-1, France -> instance-2

Geoproximity Routing

Geoproximity map

• Lets Amazon Route 53 route traffic to your resources based on the geographic location.

• You can also optionally choose to route more traffic or less to a given resource by specifying a value, known as a bias. A bias expands or shrinks the size of the geographic region from which traffic is routed to a resource.

Health check

• HTTP Health check are only for PUBLIC resouces.

  • If you want to check the health of PRIVATE resources, then use CloudWatch Metric. This means healthcheck just monitor the Metric, not that PRIVATE resources 😂

• Health check -> Automated DNS Failover.

• Route53 can monitor (the health) of the end-point

• Support methods: HTTP, HTTPS, TCP

• PASS only when the response code is 2xx or 3xx.

• Health check can work with other healthchecks.

Heallthcheck work with other Healthcheck

Trivia

• TTL is required setting value for all record types, except A

• Check TTL by nslookup -q=SOA google.com or dig google.com SOA

• Health check in Route53 are only for PUBLIC resources. 😂

• Each Amazon Route 53 account is limited to a maximum of 500 hosted zones and 10,000 resource record sets per hosted zone.

Concepts

• DNS (Domain Name Service): map domain name to IP addresses, or resources (EC2, ELB, S3 buckets, CloudFront...). For example:

  172.217.18.36  => www.google.com

• Domain Registra: Godday, お名前.com, Route53...

• Name server: server that converts name -> ip

• Top Level Domain: .com, .vn

• Second Level Domain: google.com, aws.com

• TTL (Time to live): the client will cache the result (return from DNS server) for TTL minutes. To save cost, set the TTL value higher for lesser requests to DNS server.