Route 53 configures and manages domains: domain registration, DNS (Domain Name System) service, and health checking. – DNS uses port 53. That is how the name comes from.
- Route 53 is commonly used with ELB (Elastic Load Balancer) and CloudFront.
- Split-View DNS option (Hosted zones) allows maintaining both a private and a public hosted zone with the same domain name.
- The private hosted zones are allowed with VPCs. Associated VPCs can see the interval version of a website by using the private zone’s A record.
- A public hosted zone holds the information about how to route the public domain name. The host (www) portion is not included in a public zone’s naming convention.
- In Route 53, the TTL (Time to Live) is the amount of time that the DNS resolver will cache the record.
- When creating an A record, you need to specify TTL, a routing policy, and IP values.
Routing Policies
- Simple routing
- It uses a single record with multiple IPs within a hosted zone. When queried, all the values are returns in a random order. Simple and default.
- It evenly spreads requests but no performance control (no LB)
- Limitations: No granular health checks; No performance control; The alias option can only provide a single AWS resource, not multiple.
- Weighted routing
- It controls (splits) the amount of traffic based on the ratio (percentage) of the weight of each record to the total weight of associated records.
- Weighted routing can be used to test new features of an application by allowing users a gradual introduction to the features.
- Failover routing: active/passive set up
- It uses two record sets with the same name (the primary when healthy, the secondary when unhealthy). Route 53 monitors the health of the primary site.
- Latency-based routing
- Route53 consults a latency database and resolves the host with the lowest latency.
- For each record for latency-based routing, you need to specify a region.
- It is not based on the distance or geolocation. It is based on the network performance.
- Geolocation routing
- It serves the traffic based on the geographic region.
- The requester’s IP is not placed in the specified region, the traffic is routed to the default record.
- If locations are overlapped, the most specific location is used.
- Geoproximity routing
- It must use Route 53 Traffic flow – geographic location of resources.
- Multivalue Answer routing
- It may return multiple values, such as IP addresses (simple routing with health checks).
Route 53 Health Checks
- You can set health checks on individual record sets. A failed record set will be removed from Route 53 until it passes the health check.
- Types of health checks
- End Point Checking – agreed way with an agreed frequency (HTTP, HTTPS, TCP – 10 or 30 seconds)
- Calculated health checks – monitoring various checks and combine them
- CloudWatch alarms – monitoring CloudWatch alarms from a large range of geographical servers.
- It provides a summarized report from multiple health checks.
- Health checks are charged based on the number of checks within the month. (per month base)
Limits
- Route 53 has a default limit of 50 domain names.
- The limit can be increased by contacting AWS support.
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