How do health checks work in Amazon Route 53, and what types of health check configurations are available?
Amazon Route 53 health checks monitor the health of resources, such as web servers or email servers. They work by sending requests to the resource and evaluating its response based on specified criteria.
There are three types of health check configurations available :
1. Basic Health Check : Monitors a single endpoint by sending regular pings (HTTP/HTTPS/TCP) and checking for expected responses within a timeout period.
2. Calculated Health Check : Combines multiple basic health checks into one aggregated status using logical operators (AND/OR). Useful for monitoring complex systems with multiple components.
3. Latency Measurement Health Check : Measures latency between health checkers and endpoints in different AWS regions, allowing routing decisions based on lowest latency.
Additional configuration options include :
1. Request interval : Time between consecutive health check requests.
2. Failure threshold : Number of consecutive failures before marking a resource unhealthy.
3. Inverted health check : Marks a resource healthy if it fails the health check, useful for detecting maintenance mode.
4. String matching : Searches for specific strings in the response body to determine health status.
