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fix(instrumentation-asgi): remove high cardinal path from span name #2650

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076144c
fix(instrumentation-asgi): remove high cardinal path from span name
srikanthccv Jul 2, 2024
251b3c1
resolve conflicts
srikanthccv Jul 26, 2024
5de29db
fix asgi instrumentation
srikanthccv Jul 26, 2024
2da1dac
Merge branch 'main' into fix-asgi-name
srikanthccv Aug 31, 2024
3ed3922
Fix merge conflicts
srikanthccv Mar 8, 2025
1c1b748
Fix name and update tests
srikanthccv Mar 8, 2025
3f5758e
Merge branch 'fix-asgi-name' of github.com:srikanthccv/opentelemetry-…
srikanthccv Mar 8, 2025
99923c2
Format and CHANGELOG
srikanthccv Mar 9, 2025
498527f
Merge branch 'main' into fix-asgi-name
srikanthccv Nov 8, 2025
95b0c48
chore: fix test
srikanthccv Nov 8, 2025
f98022e
chore: update CHANGELOG.md
srikanthccv Nov 8, 2025
e2ff03e
chore: fix format
srikanthccv Nov 8, 2025
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3 changes: 3 additions & 0 deletions CHANGELOG.md
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Original file line number Diff line number Diff line change
Expand Up @@ -42,6 +42,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
([#3882](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/3882))
- `opentelemetry-instrumentation-aiohttp-server`: delay initialization of tracer, meter and excluded urls to instrumentation for testability
([#3836](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/3836))
- `opentelemetry-instrumentation-asgi` remove high cardinal path from span name
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@emdneto emdneto Nov 10, 2025 •
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plus remove the protocol type from the span name if http?

([#2650](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2650))


## Version 1.38.0/0.59b0 (2025-10-16)

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19 changes: 8 additions & 11 deletions ...ion/opentelemetry-instrumentation-asgi/src/opentelemetry/instrumentation/asgi/__init__.py
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@aabmass aabmass Nov 10, 2025

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Good to see you @srikanthccv 👋

Is the span name being modified here supposed to follow the OTel HTTP server semconv or is it a more internal span? This change would be a breakage for anyone relying on this particular name, but if it's not the main {method} {target} span it may be OK.

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@srikanthccv srikanthccv Nov 10, 2025

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Is the span name being modified here supposed to follow the OTel HTTP server semconv or is it a more internal span?

Correct, specifically this part of the spec: If there is no (low-cardinality) {target} available, HTTP span names SHOULD be {method}. The path value of the ASGI scope for both HTTP and WebSocket contains the non-templatized path. The change in this PR removes the path as the target and just sets the method as recommended.

Some examples image

This change would be a breakage for anyone relying on this particular name

Agreed, but at the same time, it doesn't follow the semantic convention and spec guidelines for span names. I would say it's a necessary breaking change. Even from the end-user perspective, I believe this is a useful change; otherwise, IDs (from messaging-adjacent apps, in my experience) become part of the name, leading to no meaningful aggregation for server spans. In many deployments, the spanmetrics connector is used to derive metrics from these spans, which creates a problem.

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@aabmass aabmass Nov 11, 2025

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Agreed, but at the same time, it doesn't follow the semantic convention and spec guidelines for span names. I would say it's a necessary breaking change. Even from the end-user perspective, I believe this is a useful change

Ya I agree, maybe we can just gate this behind the new semconv stability opt in like we do here?

opentelemetry-python-contrib/instrumentation/opentelemetry-instrumentation-asgi/src/opentelemetry/instrumentation/asgi/__init__.py

Lines 741 to 743 in bd3c1f2

attributes = collect_request_attributes(
scope, self._sem_conv_opt_in_mode
)

How hard would that be to do?

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@srikanthccv srikanthccv Nov 11, 2025

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Let me take a look at it.

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@srikanthccv srikanthccv Nov 11, 2025

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I went through the code. It should be possible to keep the old and new name following the opt in mode. Let me know if we should make it opt-in.

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@tammy-baylis-swi tammy-baylis-swi Nov 12, 2025

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Hi! 👋

There is a similar PR open for the aiohttp server instrumentation that will also introduce a breaking change to span name in order to follow semconv and reduce cardinality: #3896 (comment) . @aabmass should that PR also include an opt-in? cc @krnr

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@aabmass aabmass Nov 12, 2025

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IMO it would be better since the purpose of the opt-in was to prevent breaking people

Any objections to that though? Does it work for you @srikanthccv ?

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@srikanthccv srikanthccv Nov 12, 2025

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Sounds good to me 👍

Original file line number Diff line number Diff line change
Expand Up @@ -506,15 +506,12 @@ def get_default_span_details(scope: dict) -> Tuple[str, dict]:
Returns:
a tuple of the span name, and any attributes to attach to the span.
"""
path = scope.get("path", "").strip()
method = sanitize_method(scope.get("method", "").strip())
if method == "_OTHER":
method = "HTTP"
if method and path: # http
return f"{method} {path}", {}
if path: # websocket
return path, {}
return method, {} # http with no path
if scope.get("type") == "http":
method = sanitize_method(scope.get("method", "").strip())
if method == "_OTHER":
method = "HTTP"
return method, {}
return scope.get("type", ""), {}


def _collect_target_attribute(
Expand Down Expand Up @@ -863,7 +860,7 @@ def _get_otel_receive(self, server_span_name, scope, receive):
@wraps(receive)
async def otel_receive():
with self.tracer.start_as_current_span(
" ".join((server_span_name, scope["type"], "receive"))
" ".join((server_span_name, "receive"))
) as receive_span:
message = await receive()
if callable(self.client_request_hook):
Expand Down Expand Up @@ -894,7 +891,7 @@ def _set_send_span(
):
"""Set send span attributes and status code."""
with self.tracer.start_as_current_span(
" ".join((server_span_name, scope["type"], "send"))
" ".join((server_span_name, "send"))
) as send_span:
if callable(self.client_response_hook):
self.client_response_hook(send_span, scope, message)
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