@opentelemetry/propagator-ot-trace NPM

OpenTelemetry OTTracePropagator

OT Trace Format

Header Name	Description	Required
`ot-tracer-traceid`	uint64 encoded as a string of 16 hex characters	yes
`ot-tracer-spanid`	uint64 encoded as a string of 16 hex characters	yes
`ot-tracer-sampled`	boolean encoded as a string with the values `'true'` or `'false'`	no
`ot-baggage-*`	repeated string to string key-value baggage items; keys are prefixed with `ot-baggage-` and the corresponding value is the raw string.	if baggage is present

Interop and trace ids

The OT trace propagation format expects trace ids to be 64 bits. In order to interop with OpenTelemetry, trace ids need to be truncated to 64 bits before sending them on the wire. When truncating, the least significant (right-most) bits MUST be retained. For example, a trace id of 3c3039f4d78d5c02ee8e3e41b17ce105 would be truncated to ee8e3e41b17ce105.

Baggage Notes

Baggage keys and values are validated according to rfc7230. Any keys or values that would result in invalid HTTP headers will be silently dropped during inject.

OT Baggage is represented as multiple headers where the names are carrier dependent. For this reason, they are omitted from the fields method. This behavior should be taken into account if your application relies on the fields functionality. See the specification for more details.

Example Usage

const api = require('@opentelemetry/api');
const { OTTracePropagator } = require('@opentelemetry/propagator-ot-trace');

api.propagation.setGlobalPropagator(new OTTracePropagator());