MUST be unique for each instance of the same @code service.namespace,service.name @endcode pair (in other words @code service.namespace,service.name,service.instance.id @endcode triplet MUST be globally unique). The ID helps to distinguish instances of the same service that exist at the same time (e.g. instances of a horizontally scaled service).
Implementations, such as SDKs, are recommended to generate a random Version 1 or Version 4 RFC 4122 UUID, but are free to use an inherent unique ID as the source of this value if stability is desirable. In that case, the ID SHOULD be used as source of a UUID Version 5 and SHOULD use the following UUID as the namespace: @code 4d63009a-8d0f-11ee-aad7-4c796ed8e320 @endcode.
UUIDs are typically recommended, as only an opaque value for the purposes of identifying a service instance is needed. Similar to what can be seen in the man page for the @code /etc/machine-id @endcode file, the underlying data, such as pod name and namespace should be treated as confidential, being the user's choice to expose it or not via another resource attribute.
For applications running behind an application server (like unicorn), we do not recommend using one identifier for all processes participating in the application. Instead, it's recommended each division (e.g. a worker thread in unicorn) to have its own instance.id.
It's not recommended for a Collector to set @code service.instance.id @endcode if it can't unambiguously determine the service instance that is generating that telemetry. For instance, creating an UUID based on @code pod.name @endcode will likely be wrong, as the Collector might not know from which container within that pod the telemetry originated. However, Collectors can set the @code service.instance.id @endcode if they can unambiguously determine the service instance for that telemetry. This is typically the case for scraping receivers, as they know the target address and port. */ static constexpr const char *kServiceInstanceId = "service.instance.id"; /** Logical name of the service.
MUST be the same for all instances of horizontally scaled services. If the value was not specified, SDKs MUST fallback to @code unknown_service: @endcode concatenated with @code process.executable.name @endcode, e.g. @code unknown_service:bash @endcode. If @code process.executable.name @endcode is not available, the value MUST be set to @code unknown_service @endcode. */ static constexpr const char *kServiceName = "service.name"; /** A namespace for @code service.name @endcode.
A string value having a meaning that helps to distinguish a group of services, for example the team name that owns a group of services. @code service.name @endcode is expected to be unique within the same namespace. If @code service.namespace @endcode is not specified in the Resource then @code service.name @endcode is expected to be unique for all services that have no explicit namespace defined (so the empty/unspecified namespace is simply one more valid namespace). Zero-length namespace string is assumed equal to unspecified namespace. */ static constexpr const char *kServiceNamespace = "service.namespace"; /** The version string of the service API or implementation. The format is not defined by these conventions. */ static constexpr const char *kServiceVersion = "service.version"; } // namespace service } // namespace semconv OPENTELEMETRY_END_NAMESPACE