Skip to content

Latest commit

 

History

History
59 lines (47 loc) · 2.69 KB

route53.md

File metadata and controls

59 lines (47 loc) · 2.69 KB

Amazon Route 53

  • It is a highly available, scalable, fully managed and authoritative DNS
    • Authoritative: the customer can update the DNS records
  • Route 53 is also a Domain Registrar
  • We have the ability to check the health of our resources to which we create DNS records
  • It is the only AWS service which provides 100% availability SLA

DNS Records

  • Each record contains:
    • Domain/subdomain name: example com
    • Record type: A, AAAA, CNAME, etc.
    • Value: for example an IP address
    • Routing Policy: how Route 53 responds to queries
    • TTL: amount of time the record is cached at the DNS server
  • Route 53 supports a bunch of record types:
    • A / AAAA/ CNAME / NS
    • Advanced records: CAA / DS / MX / NAPTR / PTR / SOA / TXT / SPF / SRV
  • Important record types (from the exam perspective):
    • A: maps a hostname to an IPv4 address
    • AAAA : maps a hostname to an IPv6 address
    • CNAME: maps a hostname to another hostname:
      • The target is a domain name which must have an A or AAAA record
      • We can't create a CNAME record for the top node of a DNS namespace (Zone Apex)
    • NS: Name Servers for the Hosted Zone

Hosted Zones

  • Hosted Zones are containers for records that define how to route traffic to a domain and its subdomains
  • Public Hosted Zones: contains records that specify how to route traffic on the internet
  • Private Hosted Zones: contains records that can be resolved within one or more VPCs (private domain names)
  • We pay $0.5 per month for any hosted zone we create

Routing Policies

Weighted

  • We control the % of the requests that go to each specific resource
  • We assign each record with a relative weight:
    • Weights don't need to sum up to 100%
  • DNS records must have the same name and type
  • They can be associated with health checks
  • Use cases: load balancing between regions, testing new application versions, etc.
  • We can assign a weight of 0 to a record to stop sending traffic to the resource
  • If all the records have weight of 0, then all the resources will resolved equally

Latency-based

  • The hosted zone will resolve the resource that has the least latency for the requestor
  • Helpful when latency is a priority for the users
  • Latency is based on traffic between users and AWS Regions
  • Records can be associated with health checks

Failover (Active-Passive)

  • With a Failover record, Route 53 actively returns a primary resource
  • If there is a failure for the primary resource, the secondary resource will be returned
  • When creating a Failover record, we have to select if the record is primary or secondary