Health Checks and DNS Failover

Route 53 health checks continuously monitor the health of your endpoints—web servers, load balancers, or any HTTP/HTTPS/TCP endpoint accessible on the internet. Based on health check results, Route 53 can automatically update DNS routing to avoid sending traffic to unhealthy resources.

Health checks are billed per health check per month. Route 53 global health checkers (located in multiple Regions) probe your endpoint simultaneously, providing redundancy in the health checking itself. An endpoint is considered unhealthy only when a threshold number of checkers agree it has failed.

Endpoint health checks monitor a specific IP address or domain name with your chosen protocol (HTTP, HTTPS, or TCP), port, and optional path. For HTTP/HTTPS checks, Route 53 verifies that the endpoint returns a 2xx or 3xx HTTP status code within the timeout period. For HTTPS checks, it optionally validates the TLS certificate.

Key configuration options: request interval (10 or 30 seconds—10 seconds is faster detection but costs more), failure threshold (1–10 consecutive failures before marking unhealthy), and string matching (optionally verify the response body contains a specific string).