OpenTelemetry defines certain semantic conventions for resource attributes related to hostnames. If an OpenTelemetry Protocol (OTLP) payload for any signal type has known hostname resource attributes, Datadog honors these conventions and tries to use its value as a hostname. The default hostname resolution algorithm is built with compatibility with the rest of Datadog products in mind, but you can override it if needed.
Conventions are checked in resource attributes the following order, and the first valid hostname is used. If no valid conventions are present, the fallback hostname logic is used. This fallback logic varies by product.
Check Datadog-specific conventions: host and datadog.host.name.
Check cloud provider-specific conventions for AWS, Azure and GCP.
Check Kubernetes-specific conventions.
If no specific conventions are found, fall back to host.id and host.name.
The following sections explain each set of conventions in more detail.
The host and datadog.host.name conventions are Datadog-specific conventions. They are considered first and can be used to override the hostname detected using the usual OpenTelemetry semantic conventions. host is checked first and then datadog.host.name is checked if host was not set.
Prefer using the datadog.host.name convention since it is namespaced, and it is less likely to conflict with other vendor-specific behavior.
When using the OpenTelemetry Collector, you can use the transform processor to set the datadog.host.name convention in your pipelines. For example, to set the hostname as my-custom-hostname in all metrics, traces, and logs on a given pipeline, use the following configuration:
transform:metric_statements:&statements- context:resourcestatements:- set(attributes["datadog.host.name"], "my-custom-hostname")trace_statements:*statements# Use the same statements as in metricslog_statements:*statements# Use the same statements as in metrics
Don’t forget to add the transform processor to your pipelines.
Due to how the backend processes deduplicate hostnames, you may occasionally see an alias for your host. If this causes issues for you, please contact support.
The cloud.provider resource attribute is used to determine the cloud provider. Further resource attributes are used to determine the hostname for each specific platform. If cloud.provider or any of the expected resource attributes are missing, the next set of conventions is checked.
If cloud.provider has the value aws, the following conventions are checked:
Check aws.ecs.launchtype to determine if the payload comes from an ECS Fargate task. If so, use aws.ecs.task.arn as the identifier with tag name task_arn.
Otherwise, use host.id as the hostname. This matches the EC2 instance id.
If cloud.provider has the value gcp, the following conventions are checked:
Check that both host.name and cloud.account.id are available and have the expected format, remove the prefix from host.name, and merge both into a hostname.
If k8s.node.name and the cluster name are available, the hostname is set to <node name>-<cluster name>. If only k8s.node.name is available, the hostname is set to the node name.
To get the cluster name, the following conventions are checked:
Check k8s.cluster.name and use it if present.
If cloud.provider is set to azure, extract the cluster name from azure.resourcegroup.name.
If cloud.provider is set to aws, extract the cluster name from the first resource attribute starting with ec2.tag.kubernetes.io/cluster/.
If none of the above conventions are present, the host.id and host.name resource attributes are used as-is to determine the hostname. host.id is checked first and then host.name is checked if host.id was not set.
Note: The OpenTelemetry specification allows host.id and host.name to have values that may not match those used by other Datadog products in a given environment. If using multiple Datadog products to monitor the same host, you may have to override the hostname using datadog.host.name to ensure consistency.
The fallback hostname logic is used. This logic generates a hostname for the machine where
the Datadog Exporter is running, which is compatible with the rest of Datadog products, by checking the following sources:
The hostname field in the Datadog Exporter configuration.
Cloud provider API.
Kubernetes host name.
Fully qualified domain name.
Operating system host name.
This may lead to incorrect hostnames in gateway deployments. To avoid this, use the resource detection processor in your pipelines to ensure accurate hostname resolution.
