Semantic Conventions for Event Attributes

Status: Experimental

This document describes the attributes of standalone Events that are represented in the data model by LogRecords.

The following semantic conventions for events are defined:

• General: General semantic attributes that may be used in describing Events.
• Exceptions: Semantic attributes that may be used in describing exceptions as events.

General event attributes

Events are recorded as LogRecords that are shaped in a special way: Event LogRecords have the attributes event.domain and event.name (and possibly other LogRecord attributes).

The event.domain attribute is used to logically separate events from different systems. For example, to record Events from browser apps, mobile apps and Kubernetes, we could use browser, device and k8s as the domain for their Events. This provides a clean separation of semantics for events in each of the domains.

Within a particular domain, the event.name attribute identifies the event. Events with same domain and name are structurally similar to one another. For example, some domains could have well-defined schema for their events based on event names.

When recording events from an existing system as OpenTelemetry Events, it is possible that the existing system does not have the equivalent of a name or requires multiple fields to identify the structure of the events. In such cases, OpenTelemetry recommends using a combination of one or more fields as the name such that the name identifies the event structurally. It is also recommended that the event names have low-cardinality, so care must be taken to use fields that identify the class of Events but not the instance of the Event.

[1]: Events across different domains may have same event.name, yet be unrelated events.

event.domain has the following list of well-known values. If one of them applies, then the respective value MUST be used, otherwise a custom value MAY be used.