[VimalN2005]

Description

The backwards-compatible middleware exported by opentelemetry.instrumentation.aiohttp_server is instantiated at import time and captures _tracer = None because AioHttpServerInstrumentor().instrument() has not yet executed. Later requests routed through this middleware fail with AttributeError: 'NoneType' object has no attribute 'start_as_current_span' and return HTTP 500.

Resolve the tracer dynamically at request time when _tracer was captured as None, falling back to the module tracer (or global tracer), while preserving explicit tracer provider bindings configured via create_aiohttp_middleware(tracer_provider=...).

Fixes #5164

Type of change

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• I am a human and not a bot
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Added changelog entry in .changelog/5164.fixed

[opentelemetry-pr-dashboard]

Pull request dashboard status

Waiting on the author · refreshed 2026-10-30 18:35 UTC

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• Top-level threads: 1

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[dipesh-svg]

Hey @VimalN2005, took a quick look. The 3 red checks are all small things:

1. changelog: the fragment needs to be named after the PR number, not the issue, so .changelog/5164.fixed → .changelog/5256.fixed.
2. precommit: ruff flags I001 in test_aiohttp_server_integration.py. There's an extra blank line after from opentelemetry import trace. Running pre-commit run --all-files (or ruff check --fix) fixes it.
3. CI / check only fails because misc failed.

Since misc failed, the aiohttp-server tests got skipped, so they haven't actually run in CI yet. The branch is also behind main, so it's worth updating it too. Once it's green it'll probably get reviewed faster.

[VimalN2005]

Hi @dipesh-cvg,

Thank you for the quick and helpful feedback! I have addressed all points:

1. Renamed .changelog/5164.fixed to .changelog/5256.fixed.
2. Fixed the extra blank line / Ruff formatting (I001) in test_aiohttp_server_integration.py.
3. Merged the latest main into this branch.

Everything is pushed now and ready for review. Thanks again!

[dipesh-svg]

Nice, thanks for the quick update @VimalN2005! Just a heads-up: the CI workflows on the new commit are waiting for a maintainer to approve them (they show "action_required"), so the checks haven't run yet. Might be worth mentioning that in the Slack thread so someone can approve the run. Good luck with the review!