Context propagation and identities

J7M separates request relationships, authenticated callers, application activations and remote objects. Preserve that distinction in logs and authorization: a trace ID helps correlate work, but it does not grant permission to perform it.

Relate nested work

The following example is adapted from the context contract tests and uses types in org.j7m.middleware.api.reliability.

CausalContext root = new CausalContext("trace-a", "span-a", "");
CausalContext child = root.child();
assert child.traceId().equals(root.traceId());
assert child.parentSpanId().equals(root.spanId());
assert !child.spanId().equals(root.spanId());

CorrelationContext request = new CorrelationContext("corr-a", "invoke-a", "");
CorrelationContext nested = request.nestedInvocation();
assert nested.correlationId().equals(request.correlationId());
assert nested.parentInvocationId().equals(request.invocationId());

CausalContext.root() creates a root with no parent. Child creation preserves the trace and allocates a new span. Correlation context preserves a business/request correlation ID while assigning each nested invocation a distinct invocation ID. This is a source-derived fragment; Java assertions require -ea when used as executable checks.

The invocation/transport integration propagates these ID-only contexts. Use the host's configuration and context facilities for managed invocation access; constructing a context record alone does not install it as the current caller context. Keep credentials, user documents and payloads out of these IDs and metadata.

Use the right identity

Identity	Identifies
ApplicationIdentity	Exact application coordinate, display name and declared trust domain
ApplicationInstanceIdentity	One active application instance and its hosting runtime
DeploymentIdentity	The deployment represented by the hosting operations model
ActivationIdentity	A particular activation of deployed application code
RuntimeServiceIdentity	A service export associated with its runtime/application activation
CallerIdentity	Caller information available to application invocation policy
RuntimeIdentity	The middleware runtime
ObjectRef	One concrete remote object incarnation and its routing/lifetime metadata

Do not use a display name as an authorization key or collapse two activations because they have the same application coordinate. Conversely, a new trace/span does not create a new application or remote object identity.

Digests, coordinates, endpoint metadata and object references are identifiers rather than bearer credentials. Server-side authentication and authorization remain authoritative, including local proxy dispatch. See services and references, security and monitoring.