A resource represents the entity producing telemetry as resource attributes. For example, a process producing telemetry that is running in a container on Kubernetes has a process name, a pod name, a namespace, and possibly a deployment name. All four of these attributes can be included in the resource.

In your observability backend, you can use resource information to better investigate interesting behavior. For example, if your trace or metrics data indicate latency in your system, you can narrow it down to a specific container, pod, or Kubernetes deployment.

If you use Jaeger as your observability backend, resource attributes are grouped under the Process tab:

A screenshot from Jaeger showing an example output of resource attributes associated to a trace

A resource is added to the TraceProvider or MetricProvider when they are created during initialization. This association can not be changed later. After a resource is added, all spans and metrics produced from a Tracer or Meter from the provider will have the resource associated with them.

Semantic Attributes with SDK-provided Default Value

There are attributes provided by the OpenTelemetry SDK. One of them is the, which represents the logical name of the service. By default, SDKs will assign the value unknown_service for this value, so it is recommended to set it explicitly, either in code or via setting the environment variable OTEL_SERVICE_NAME.

Additionally, the SDK will also provides the following resource attributes to identify itself:, telemetry.sdk.language and telemetry.sdk.version.

Resource Detectors

Most language-specific SDKs provide a set of resource detectors that can be used to automatically detect resource information from the environment. Common resource detectors include:

Custom resources

You can also provide your own resource attributes. You can either provide them in code or via populating the environment variable OTEL_RESOURCE_ATTRIBUTES. If applicable, use the semantic conventions for your resource attributes. For example, you can provide the name of your deployment environment using deployment.environment:

env OTEL_RESOURCE_ATTRIBUTES=deployment.environment=production yourApp