Route 53 Quiz

A. Use Route 53 health checks to monitor the endpoints.
Route 53 health checks can be used for any endpoint that can be accessed via the Internet. Hence, this would be an ideal option for monitoring endpoints.
AWS Documentation mentions the following:
You can configure a health check that monitors an endpoint that you specify either by IP address or by domain name. At regular intervals that you specify, Route 53 submits automated requests over the internet to your application, server, or other resource to verify that it’s reachable, available and functional. For more information on Route 53 Health checks, please refer to the URL below.
https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/dns-failover-simple-configs.htmlNote:As per AWS,Once enabled, Route 53 automatically configures and manages health checks for individual ELB nodes. Route 53 also takes advantage of the EC2 instance health checking that ELB performs. By combining the results of health checks of your EC2 instances and your ELBs, Route 53 DNS Failover is able to evaluate the health of the load balancer and the health of the application running on the EC2 instances behind it. In other words, if any part of the stack goes down, Route 53 detects the failure and routes traffic away from the failed endpoint.For more information, please visit:https://aws.amazon.com/blogs/aws/amazon-route-53-elb-integration-dns-failover/AWS documentation states, that you can create a Route 53 resource record that points to an address outside AWS, you can set up health checks for parts of your application running outside AWS, and you can fail over to any endpoint that you choose, regardless of location. For example, you may have a legacy application running in a datacenter outside AWS and a backup instance of that application running within AWS. You can set up health checks of your legacy application running outside AWS, and if the application fails the health checks, you can fail over automatically to the backup instance in AWS.Please refer:https://aws.amazon.com/route53/faqs/Note: As per AWS,Route 53 has health checkers in locations around the world. When you create a health check that monitors an endpoint, health checkers start to send requests to the endpoint that you specify to determine whether the endpoint is healthy. You can choose which locations you want Route 53 to use, and you can specify the interval between checks: every 10 seconds or every 30 seconds. Note that Route 53 health checkers in different data centers don’t coordinate with one another, so you’ll sometimes see several requests per second regardless of the interval you chose, followed by a few seconds with no health checks at all.Each health checker evaluates the health of the endpoint based on two values:Response timeWhether the endpoint responds to a number of consecutive health checks that you specify (the failure threshold)Route 53 aggregates the data from the health checkers and determines whether the endpoint is healthy:If more than 18% of health checkers report that an endpoint is healthy, Route 53 considers it healthy.If 18% of health checkers or fewer report that an endpoint is healthy, Route 53 considers it unhealthy.The response time that an individual health checker uses to determine whether an endpoint is healthy depends on the type of health check:HTTP and HTTPS health checks, TCP health checks or HTTP and HTTPS health checks with string matching.Regarding your specific query where we are having more than 2 servers for the website, AWS docs states that:When you have more than one resource performing the same function—for example, more than one HTTP server or mail server—you can configure Amazon Route 53 to check the health of your resources and respond to DNS queries using only the healthy resources. For example, suppose your website, example.com, is hosted on six servers, two each in three data centers around the world. You can configure Route 53 to check the health of those servers and to respond to DNS queries for example.com using only the servers that are currently healthy. The configuration details are provided in the second link.Please refer the following links for more information.https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/dns-failover-determining-health-of-endpoints.htmlhttps://docs.aws.amazon.com/Route53/latest/DeveloperGuide/dns-failover-configuring.html