Route53 Latency-Based Routing

Answer - B & E.

Option A is incorrect because you can set up weighted record sets as the failover or secondary recordset.

Option B is CORRECT because if the HTTP health check is not set with the weighted resource record sets of the disabled web servers, Route 53 will consider them healthy and continue to forward the traffic.

Once the health check is enabled, the DNS queries will get a response indicating that the web servers are disabled, and then the requests would get routed to the other region.

Option C is incorrect because even if the weight is lower for the region with disabled web servers, Route 53 will continue forwarding the users' requests closest to that region because it will evaluate the latency record set first.

Option D is incorrect because, even if one of the servers fails, the other server will still work, and the region should get the traffic.

Option E is CORRECT because if the “Evaluate Target Health” is not set to “Yes” for the region containing the disabled web servers, Route 53 will consider the health of the recordset as healthy and continue to route the traffic to it.

For more information on How Amazon Route 53 chooses records when Health Checking is configured, please visit the link below:

https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/health-checks-how-route-53-chooses-records.html https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/dns-failover-complex-configs.html#dns-failover-complex-configs-eth-no

The correct answer is E. You did not set “Evaluate Target Health” to “Yes” on the latency alias resource record set associated with example.com in the region where you disabled the servers.

Explanation:

The scenario described in the question involves the deployment of a web application across multiple AWS regions under the domain name example.com. The objective is to use Route53 Latency-Based Routing to serve web requests to users from the region closest to them. To ensure business continuity in case of server downtime, the configuration involves weighted record sets associated with two web servers in separate Availability Zones per region.

In such a setup, each region has a latency alias resource record set associated with example.com. Each alias resource record set contains the weighted record sets of the two web servers in the region. The weight distribution across the two record sets ensures that traffic is distributed between them in a specified proportion, which can be used to balance traffic load or provide failover capabilities.

The question asks for the reason for the failure of business continuity in case of server downtime. There can be several reasons why a server in a region can fail, but the configuration should ensure that traffic is redirected to the other server. The options provided in the question are as follows:

A. Latency resource record sets cannot be used in combination with weighted resource record sets.

This statement is incorrect. Latency alias resource record sets can be combined with weighted record sets to provide failover capabilities based on latency.

B. You did not set up an HTTP health check to one or more of the weighted resource record sets associated with the disabled web servers.

This statement is incorrect. The scenario mentions that weighted record sets are used to provide business continuity in case of server downtime. Health checks can be configured to monitor the health of the web servers associated with the weighted record sets. If a server is found to be unhealthy, Route53 can automatically route traffic to the other server.

C. The value of the weight associated with the latency alias resource record set in the region with the disabled servers is higher than the weight for the other region.

This statement is incorrect. The weights associated with the latency alias resource record sets determine the proportion of traffic to be sent to each region. The weight distribution across the two weighted record sets within each latency alias resource record set determines the proportion of traffic to be sent to each web server within the region.

D. One of the two working web servers in the other region did not pass its HTTP health check.

This statement is incorrect. The scenario mentions that weighted record sets are used to provide business continuity in case of server downtime. Health checks can be configured to monitor the health of the web servers associated with the weighted record sets. If a server is found to be unhealthy, Route53 can automatically route traffic to the other server.

E. You did not set “Evaluate Target Health” to “Yes” on the latency alias resource record set associated with example.com in the region where you disabled the servers.

This statement is correct. The option "Evaluate Target Health" should be set to "Yes" on the latency alias resource record set associated with example.com in the region where servers are disabled. This setting ensures that Route53 checks the health of the web servers associated with the weighted record sets within the latency alias resource record set before redirecting traffic to them. If Route53 finds that a web server is unhealthy, it routes traffic to the other web server associated with the weighted record set.

Therefore, the correct answer is option E: You did not set “Evaluate Target Health” to “Yes” on the latency alias resource record set associated with example.com in the region where you disabled the servers.