DjangoInstrumentor http.server.request.duration exemplars are missing span context

[tammy-baylis-swi]

Describe your environment

OS: Ubuntu
Python version: Python 3.12.7
Package version: 1.38.0/0.59b0

An app instrumented with DjangoInstrumentor via auto-instrumentation.

What happened?

If exemplars are enabled (by setting exemplar filter), some metrics generated by some instrumentors export incomplete exemplars that have timestamps and values, but are missing trace ID and span ID (not very useful). Specific metrics affected include semconv-defined http.server.request.duration and http.server.duration from DjangoInstrumentor histogram record calls.

Steps to Reproduce

1. Follow the example and provide MeterProvider with exemplar_filter=AlwaysOnExemplarFilter.
2. Run an otel-collector locally with debug metrics export.
3. Auto-instrument and run a Django app, with a route that responds after about 500ms.
4. Make requests to that route and check exported metrics.

Expected Result

Exemplar #0
     -> Trace ID: <a_valid_trace_id>
     -> Span ID: <a_valid_span_id>
     -> Timestamp: 2025-11-14 21:47:09.021649 +0000 UTC
     -> Value: 167.652562

Actual Result

Exemplar #0
     -> Trace ID:
     -> Span ID:
     -> Timestamp: 2025-11-14 21:47:09.021649 +0000 UTC
     -> Value: 167.652562

Additional context

Related to

1. FlaskInstrumentor http.server.request.duration exemplars are missing span context #3913
2. Fix exemplar support #3031

Would you like to implement a fix?

Yes

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