Values specific for failover alias records - Amazon Route 53
Routing policyRecord nameRecord typeValue/Route traffic toFailover record typeHealth checkEvaluate target healthRecord ID

Values specific for failover alias records

When you create failover alias records, you specify the following values.

For information, see the following topics:

Routing policy

Choose Failover.

Record name

Enter the name of the domain or subdomain that you want to route traffic for. The default value is the name of the hosted zone.

Note

If you're creating a record that has the same name as the hosted zone, don't enter a value (for example, an @ symbol) in the Record name field.

Enter the same name for both of the records in the group of failover records.

For more information about record names, see Record name.

Record type

The DNS record type. For more information, see Supported DNS record types.

Select the applicable value based on the AWS resource that you're routing traffic to. Select the same value for both the primary and secondary failover records:

API Gateway custom regional API or edge-optimized API

Select A — IPv4 address.

Amazon VPC interface endpoints

Select A — IPv4 address.

CloudFront distribution

Select A — IPv4 address.

If IPv6 is enabled for the distribution, create two records, one with a value of A — IPv4 address for Type, and one with a value of AAAA — IPv6 address.

Elastic Beanstalk environment that has regionalized subdomains

Select A — IPv4 address

ELB load balancer

Select A — IPv4 address or AAAA — IPv6 address

Amazon S3 bucket

Select A — IPv4 address

Another record in this hosted zone

Select the type of the record that you're creating the alias for. All types are supported except NS and SOA.

Note

If you're creating an alias record that has the same name as the hosted zone (known as the zone apex), you can't route traffic to a record for which the value of Type is CNAME. This is because the alias record must have the same type as the record you're routing traffic to, and creating a CNAME record for the zone apex isn't supported even for an alias record.

Value/Route traffic to

The value that you choose from the list or that you type in the field depends on the AWS resource that you're routing traffic to.

For information about what AWS resources you can target, see common values for alias records for value/route traffic to.

For more information about how to configure Route 53 to route traffic to specific AWS resources, see Routing internet traffic to your AWS resources.

Note

When you create primary and secondary failover records, you can optionally create one failover and one failover alias record that have the same values for Name and Record type. If you mix failover and failover alias records, either one can be the primary record.

Failover record type

Choose the applicable value for this record. For failover to function correctly, you must create one primary and one secondary failover record.

You can't create non-failover records that have the same values for Record name and Record type as failover records.

Health check

Select a health check if you want Route 53 to check the health of a specified endpoint and to respond to DNS queries using this record only when the endpoint is healthy.

Route 53 doesn't check the health of the endpoint specified in the record, for example, the endpoint specified by the IP address in the Value field. When you select a health check for a record, Route 53 checks the health of the endpoint that you specified in the health check. For information about how Route 53 determines whether an endpoint is healthy, see How Amazon Route 53 determines whether a health check is healthy.

Associating a health check with a record is useful only when Route 53 is choosing between two or more records to respond to a DNS query, and you want Route 53 to base the choice in part on the status of a health check. Use health checks only in the following configurations:

  • You're checking the health of all of the records in a group of records that have the same name, type, and routing policy (such as failover or weighted records), and you specify health check IDs for all the records. If the health check for a record specifies an endpoint that is not healthy, Route 53 stops responding to queries using the value for that record.

  • You select Yes for Evaluate Target Health for an alias record or the records in a group of failover alias, geolocation alias, latency alias, IP-based alias, or weighted alias record. If the alias records reference non-alias records in the same hosted zone, you must also specify health checks for the referenced records. If you associate a health check with an alias record and also select Yes for Evaluate Target Health, both must evaluate to true. For more information, see What happens when you associate a health check with an alias record?.

If your health checks specify the endpoint only by domain name, we recommend that you create a separate health check for each endpoint. For example, create a health check for each HTTP server that is serving content for www.example.com. For the value of Domain Name, specify the domain name of the server (such as us-east-2-www.example.com), not the name of the records (example.com).

Important

In this configuration, if you create a health check for which the value of Domain Name matches the name of the records and then associate the health check with those records, health check results will be unpredictable.

Evaluate target health

Select Yes if you want Route 53 to determine whether to respond to DNS queries using this record by checking the health of the resource specified by Endpoint.

Note the following:

API Gateway custom regional APIs and edge-optimized APIs

There are no special requirements for setting Evaluate target health to Yes when the endpoint is an API Gateway custom regional API or an edge-optimized API.

CloudFront distributions

You can't set Evaluate target health to Yes when the endpoint is a CloudFront distribution.

Elastic Beanstalk environments that have regionalized subdomains

If you specify an Elastic Beanstalk environment in Endpoint and the environment contains an ELB load balancer, Elastic Load Balancing routes queries only to the healthy Amazon EC2 instances that are registered with the load balancer. (An environment automatically contains an ELB load balancer if it includes more than one Amazon EC2 instance.) If you set Evaluate target health to Yes and either no Amazon EC2 instances are healthy or the load balancer itself is unhealthy, Route 53 routes queries to other available resources that are healthy, if any.

If the environment contains a single Amazon EC2 instance, there are no special requirements.

ELB load balancers

Health checking behavior depends on the type of load balancer:

  • Classic load balancers – If you specify an ELB Classic Load Balancer in Endpoint, Elastic Load Balancing routes queries only to the healthy Amazon EC2 instances that are registered with the load balancer. If you set Evaluate target health to Yes and either no EC2 instances are healthy or the load balancer itself is unhealthy, Route 53 routes queries to other resources.

  • Application and Network Load Balancers – If you specify an ELB Application or Network Load Balancer and you set Evaluate Target health to Yes, Route 53 routes queries to the load balancer based on the health of the target groups that are associated with the load balancer:

    • For an Application or Network Load Balancer to be considered healthy, a target group that contains targets must contain at least one healthy target. If any target group contains only unhealthy targets, the load balancer is considered unhealthy, and Route 53 routes queries to other resources.

    • A target group that has no registered targets is considered unhealthy.

Note

When you create a load balancer, you configure settings for Elastic Load Balancing health checks; they're not Route 53 health checks, but they perform a similar function. Do not create Route 53 health checks for the EC2 instances that you register with an ELB load balancer.

S3 buckets

There are no special requirements for setting Evaluate target health to Yes when the endpoint is an S3 bucket.

Amazon VPC interface endpoints

There are no special requirements for setting Evaluate target health to Yes when the endpoint is an Amazon VPC interface endpoint.

Other records in the same hosted zone

If the AWS resource that you specify in Endpoint is a record or a group of records (for example, a group of weighted records) but is not another alias record, we recommend that you associate a health check with all of the records in the endpoint. For more information, see What happens when you omit health checks?.

Record ID

Enter a value that uniquely identifies the primary and secondary records.