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Identities in SignalFx µAPM 🔗

Important

The original µAPM product, released in 2019, is now called µAPM Previous Generation (µAPM PG). In the documentation, µAPM now refers to the product released on March 31, 2020.

If you are using µAPM Previous Generation (µAPM PG), see µAPM PG Traces, Spans, Metrics, and Metadata.

An identity represents a unique set of indexed span tags for a µAPM object, and always includes at least one service. Each service has at least one identity. An identity can represent any one of these µAPM objects:

µAPM object Example Description
Service Service-1 The name of a service you instrumented and are collecting traces from.
Endpoint Service-1.Endpoint-1 The first span for a service.
Operation Service-1.Operation-1 A span within a single service.
Edge Service-1.Endpoint-1->Service-2.Endpoint-2 The span between two services.
Workflow Service-1.InitEndpoint-1 The endpoint where traces initiate.

µAPM objects can generate multiple identities that correspond to the same µAPM object. If a set of indexed span tags for a span that corresponds to a certain µAPM object is unique, the µAPM object generates a new identity for the unique set of indexed span tags.

For example, a service myService reports a tenant span tag something for its endpoint /foo/bar, and doesn’t report a tenant span tag for its endpoint /another/endpoint. Because myService reports a tenant span tag for one endpoint and not another, it forces the endpoint without a specified tenant span tag to have a tenant span tag value of unknown. As a result, the service has two unique sets of span tags, and two identities.