# HealthCheckConfig *Public DNS and HTTP namespaces only.* A complex type that contains settings for an optional health check. If you specify settings for a health check, AWS Cloud Map associates the health check with the records that you specify in `DnsConfig`. **Important** If you specify a health check configuration, you can specify either `HealthCheckCustomConfig` or `HealthCheckConfig` but not both. Health checks are basic Route 53 health checks that monitor an AWS endpoint. For information about pricing for health checks, see [Amazon Route 53 Pricing](http://aws.amazon.com/route53/pricing/). Note the following about configuring health checks. A and AAAA records If `DnsConfig` includes configurations for both `A` and `AAAA` records, AWS Cloud Map creates a health check that uses the IPv4 address to check the health of the resource. If the endpoint tthat's specified by the IPv4 address is unhealthy, Route 53 considers both the `A` and `AAAA` records to be unhealthy. CNAME records You can't specify settings for `HealthCheckConfig` when the `DNSConfig` includes `CNAME` for the value of `Type`. If you do, the `CreateService` request will fail with an `InvalidInput` error. Request interval A Route 53 health checker in each health-checking AWS Region sends a health check request to an endpoint every 30 seconds. On average, your endpoint receives a health check request about every two seconds. However, health checkers don't coordinate with one another. Therefore, you might sometimes see several requests in one second that's followed by a few seconds with no health checks at all. Health checking regions Health checkers perform checks from all Route 53 health-checking Regions. For a list of the current Regions, see [Regions](https://docs.aws.amazon.com/Route53/latest/APIReference/API_HealthCheckConfig.html#Route53-Type-HealthCheckConfig-Regions). Alias records When you register an instance, if you include the `AWS_ALIAS_DNS_NAME` attribute, AWS Cloud Map creates a Route 53 alias record. Note the following: + Route 53 automatically sets `EvaluateTargetHealth` to true for alias records. When `EvaluateTargetHealth` is true, the alias record inherits the health of the referenced AWS resource. such as an ELB load balancer. For more information, see [EvaluateTargetHealth](https://docs.aws.amazon.com/Route53/latest/APIReference/API_AliasTarget.html#Route53-Type-AliasTarget-EvaluateTargetHealth). + If you include `HealthCheckConfig` and then use the service to register an instance that creates an alias record, Route 53 doesn't create the health check. Charges for health checks Health checks are basic Route 53 health checks that monitor an AWS endpoint. For information about pricing for health checks, see [Amazon Route 53 Pricing](http://aws.amazon.com/route53/pricing/). ## Contents ** Type ** The type of health check that you want to create, which indicates how Route 53 determines whether an endpoint is healthy. You can't change the value of `Type` after you create a health check. You can create the following types of health checks: + **HTTP**: Route 53 tries to establish a TCP connection. If successful, Route 53 submits an HTTP request and waits for an HTTP status code of 200 or greater and less than 400. + **HTTPS**: Route 53 tries to establish a TCP connection. If successful, Route 53 submits an HTTPS request and waits for an HTTP status code of 200 or greater and less than 400. **Important** If you specify HTTPS for the value of `Type`, the endpoint must support TLS v1.0 or later. + **TCP**: Route 53 tries to establish a TCP connection. If you specify `TCP` for `Type`, don't specify a value for `ResourcePath`. For more information, see [How Route 53 Determines Whether an Endpoint Is Healthy](https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/dns-failover-determining-health-of-endpoints.html) in the *Route 53 Developer Guide*. Type: String Valid Values: `HTTP | HTTPS | TCP` Required: Yes ** FailureThreshold ** The number of consecutive health checks that an endpoint must pass or fail for Route 53 to change the current status of the endpoint from unhealthy to healthy or the other way around. For more information, see [How Route 53 Determines Whether an Endpoint Is Healthy](https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/dns-failover-determining-health-of-endpoints.html) in the *Route 53 Developer Guide*. Type: Integer Valid Range: Minimum value of 1. Maximum value of 10. Required: No ** ResourcePath ** The path that you want Route 53 to request when performing health checks. The path can be any value that your endpoint returns an HTTP status code of a 2xx or 3xx format for when the endpoint is healthy. An example file is `/docs/route53-health-check.html`. Route 53 automatically adds the DNS name for the service. If you don't specify a value for `ResourcePath`, the default value is `/`. If you specify `TCP` for `Type`, you must *not* specify a value for `ResourcePath`. Type: String Length Constraints: Maximum length of 255. Required: No ## See Also For more information about using this API in one of the language-specific AWS SDKs, see the following: + [AWS SDK for C\$1\$1](https://docs.aws.amazon.com/goto/SdkForCpp/servicediscovery-2017-03-14/HealthCheckConfig) + [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/servicediscovery-2017-03-14/HealthCheckConfig) + [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/servicediscovery-2017-03-14/HealthCheckConfig)