Trace Metadata and Propagation

• ID: runtime.trace-metadata
• Name: Trace metadata and propagation
• Maturity: GA
• Summary: Represents durable trace metadata via MessageTrace variants and stable execution-context keys via MessageTraceContextKeys.

What It Does

Runtime captures correlation and distributed tracing fields in durable envelopes and mediation context:

• MessageTrace variants: None, Correlated, Workflow, Distributed
• MessageTraceContextKeys: correlation, causation, tenant, and trace-context item keys
• DurableEnvelopeMetadataMapper maps trace values to and from envelope fields
• W3CTraceContextParser accepts a direct W3C trace parent or a JSON object with traceparent and optional tracestate

Public Surface

Packages

• LiteBus.Messaging.Abstractions
• LiteBus.Messaging

Requires

• runtime.message-module

Invariants

• No-trace state is represented by MessageTrace.None.Instance.
• Distributed trace shape carries correlation, causation, and trace payload.
• Malformed trace context never prevents message processing; tracing ignores it and continues without a remote parent.

Non-Goals

• Telemetry exporter configuration.

Observability

Runtime trace metadata feeds outer transport and OpenTelemetry layers; core runtime emits no trace-specific meter.

Test Coverage

Covered Use Cases

DurableMessagingValueObjectTests.MessageTrace_None_ShouldExposeSingletonInstance

• Test kind: Unit
• Expected outcome: no-trace singleton semantics hold

DurableMessagingValueObjectTests.MessageTrace_Workflow_ShouldCarryCorrelationAndCausationIds

• Test kind: Unit
• Expected outcome: workflow trace fields are preserved

DurableMessagingValueObjectTests.MessageTrace_Distributed_ShouldCarryFullTracePayload

• Test kind: Unit
• Expected outcome: distributed trace payload is preserved

Untested Use Cases

Out-of-Scope Use Cases

• Runtime generation of trace IDs.