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Route53

Main Functions
Domain Registration
DNS Service
  • Authoritative DNS service
  • If you register a domain name, Route53 automatically configured as DNS service & a hosted zone is created for the domain
Health Checking

Hosted Zone

  • Collection of Resource Record Sets (RRS) hosted by Route53, managed under a single domain name
  • Types
    • PRIVATE = info about how to route traffic for a domain & subdomain within 1+ VPC
    • PUBLIC = traffic on the Internet for a domain & subdomains
  • RRS must share same suffix
example.com V
www.example.com V
www.aws.example.com V
www.example.ca X
  • Use ALIAS RECORD (not CNAME) for hosted zone → CNAMEs not allowed for hosted zones
  • Do NOT use A records for subdomains as they refer to hardcoded IPs → use Alias Records or CNAMEs

Routing Policy

Determines how Route53 responds to queries & can be associated with Health Checks
SIMPLE
  • Default
  • Single resource that performs a function for domain
  • Route53 responds to DNS queries based only on the values in the resource record
WEIGHTED
  • Can associate multiple resources with single DNS name
  • Multiple resources for same function & want to route in PROPORTIONS
  • Conditions
    • Need to create 2+ RRS that have same DNS name & type
    • Then assign each RRS a UNIQUE ID and a RELATIVE WEIGHT
  • P(selected) = WEIGHT for a given RRS / SUM(WEIGHT for RRS in the group)
LATENCY BASED
  • Route traffic based on the lowest network latency for end user
  • When have resources performing same function in multiple AZ or regions
FAILOVER
  • ACTIVE-PASSIVE FAILOVER, where 1 resource takes ALL traffic when it's available & other when 1st resource isn't (DISASTER RECOVERY)
  • You can't create failover RRS for private hosted zones
  • Health Check Endpoint = protocol + ip:port + domain name/path
GEOLOCATION
  • Based on users geolocation
  • Also to restrict content distribution to only the locations in which you have distribution rights
    • By continent/country/state
    • Separate RRS for overlapping regions & priority goes to smallest region
  • Default RRS that handles queries:
    • From IP not mapped to location
    • From locations with no RRS specified
    • If not specified → NO ANSWER
  • Limitations
    • Can't create 2 geolocation RRS for some geolocation
    • Can't create 2 RRS with same name & type of non-geolocation RRS