CLOUD / A CONCEPT NOTE
Route 53
AWS's DNS service — also handles failover and traffic routing
Overview · mechanism
pitfall · examples
01 / THE SHORT VERSION
The idea in a few sentences.
Route 53 is AWS's DNS service. You buy domains, create hosted zones, and add record sets (A, AAAA, CNAME, TXT, MX). Beyond basic DNS, it supports routing policies: simple, weighted, latency-based, geolocation, and failover. Health checks integrated with routing let you direct traffic away from unhealthy endpoints automatically.
02 / FOLLOW THE MECHANISM
How route 53 resolves a query
Client
queries
app.example.com— their resolver asks the Route 53 authoritative name servers.Route 53
checks the record set. With latency-based routing, it knows the user's region and returns the IP of the fastest endpoint.
Health check
before returning, Route 53 verifies that the selected endpoint is healthy. If not, it returns the next best alternative.
TTL
the response includes a TTL (default 300s). The client's DNS resolver caches the answer until the TTL expires.
04 / COMMAND NOTES
Read the command, then the result.
Inspect the flags and arguments before trying an example. Snippets can need local setup, replacement values, or resources in your own environment.
list all hosted zones
aws route53 list-hosted-zoneslist all DNS records in a zone
aws route53 list-resource-record-sets --hosted-zone-id ZONE_ID05 / CHECK YOURSELF
Could you explain Route 53 to a teammate?
Try it out loud in two sentences: what it is, and the one detail that changes the picture. If you stall, the gap is the part to reread.
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