- Registering domains.
- Host Zones and managed Nameservers
- Global service, single DB
- Globally resiliance (Data copied to all regions)
- Route 53’s DNS services does not support DNSSEC at this time
- A R53 Hosted Zone is DNS database for a domain.
- Public R53 Hosted zone is hosted on R53 for public DNS servers.
- Globally Resiliant.
- Atleast 4 R53 resolvers are deployed in that domain.
- Created automatically when Domain is regisetered via R53. Can be created separately when domain is registered elsewhere.
- Hosts DNS records.
- When used hosted zone, it's autoritative for that domain in R53.
- When we have multiple records of same type and same priority, client will get IP addresses in random orders.
- R53 Health check can determine health of resources pointed by IP periodically and will return only healthy IPs.
- Health checks are separate from records but are used by them.
- Health checkers are located globally.
- Check occurs every 30 seconds by default. That period can be reduced to 10 secods at some cost.
- TCP, HTTP/HTTPS, HTTP/HTTPS with string matching.
- In TCP: Check is to be able to establish connection within 10 seconds.
- In HTTP/HTTPS: Check is to be able to establish a TCP connection, calling HTTP(S) endpoint and receiving 200 response within 4-5 seconds.
- In HTTP/HTTPS string matching: Check is same as above, additioanlly body is checked and desired string to be returned within 5120 bytes.
- Two status, Healthy or Unhealthy.
- Type of checks: Endpoint check, Cloudwatch Alarm checks (react to cloudwatch alarm), Calculated checks (Checks of checks).
- Simple:
- Let us configure standard DNS record.
- Default.
- Single Record.
- No health checks.
- Failover
- Two records of same name and type.
- One primary and other Secondary.
- Each record has associated health check.
- Default is primary as long is healthy, secondary is used when primary is unhealthy.
- Weighted
- Multiple records of same name, we provide weight of each record.
- Records are returned based on their weight in total weight of same name.
- Load balancing, testing new version.
- Latency-based
- Multiple records of same name, we provide region.
- Records are returned based on their latency from source request based on lowest latency.
- Geolocation
- Multiple records of same name, we provide location.
- When a request happens, search is done in country, continent and default in that order.
- If health check fails, request is passed over to higher state.
- Multi-value
- One record, one name and multiple values.
- No health check available.
- Public hosted zones are available to public internet, while private hosted zones are available only to VPCS they're associated with.