opentelemetry-instrumentation-aiohttp-client: fix metric attribute leakage

CHANGELOG.md

@@ -50,6 +50,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#3904](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/3904))
 - build: bump ruff to 0.14.1
   ([#3842](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/3842))
+- `opentelemetry-instrumentation-aiohttp-client`: Fix metric attribute leakage 
+  ([#3936](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/3936))
 
 ## Version 1.38.0/0.59b0 (2025-10-16)
 

instrumentation/opentelemetry-instrumentation-aiohttp-client/src/opentelemetry/instrumentation/aiohttp_client/__init__.py

@@ -287,8 +287,6 @@ def create_trace_config(
             explicit_bucket_boundaries_advisory=HTTP_DURATION_HISTOGRAM_BUCKETS_NEW,
         )
 
-    metric_attributes = {}
-
     excluded_urls = get_excluded_urls("AIOHTTP_CLIENT")
 
     def _end_trace(trace_config_ctx: types.SimpleNamespace):
@@ -299,7 +297,7 @@ def _end_trace(trace_config_ctx: types.SimpleNamespace):
 
         if trace_config_ctx.duration_histogram_old is not None:
             duration_attrs_old = _filter_semconv_duration_attrs(
-                metric_attributes,
+                trace_config_ctx.metric_attributes,
                 _client_duration_attrs_old,
                 _client_duration_attrs_new,
                 _StabilityMode.DEFAULT,
@@ -310,7 +308,7 @@ def _end_trace(trace_config_ctx: types.SimpleNamespace):
             )
         if trace_config_ctx.duration_histogram_new is not None:
             duration_attrs_new = _filter_semconv_duration_attrs(
-                metric_attributes,
+                trace_config_ctx.metric_attributes,
                 _client_duration_attrs_old,
                 _client_duration_attrs_new,
                 _StabilityMode.HTTP,
@@ -348,7 +346,7 @@ async def on_request_start(
             sem_conv_opt_in_mode,
         )
         _set_http_method(
-            metric_attributes,
+            trace_config_ctx.metric_attributes,
             method,
             sanitize_method(method),
             sem_conv_opt_in_mode,
@@ -359,12 +357,12 @@ async def on_request_start(
             parsed_url = urlparse(request_url)
             if parsed_url.hostname:
                 _set_http_host_client(
-                    metric_attributes,
+                    trace_config_ctx.metric_attributes,
                     parsed_url.hostname,
                     sem_conv_opt_in_mode,
                 )
                 _set_http_net_peer_name_client(
-                    metric_attributes,
+                    trace_config_ctx.metric_attributes,
                     parsed_url.hostname,
                     sem_conv_opt_in_mode,
                 )
@@ -376,7 +374,9 @@ async def on_request_start(
                     )
             if parsed_url.port:
                 _set_http_peer_port_client(
-                    metric_attributes, parsed_url.port, sem_conv_opt_in_mode
+                    trace_config_ctx.metric_attributes,
+                    parsed_url.port,
+                    sem_conv_opt_in_mode,
                 )
                 if _report_new(sem_conv_opt_in_mode):
                     _set_http_peer_port_client(
@@ -411,7 +411,7 @@ async def on_request_end(
         _set_http_status_code_attribute(
             trace_config_ctx.span,
             params.response.status,
-            metric_attributes,
+            trace_config_ctx.metric_attributes,
             sem_conv_opt_in_mode,
         )
 
@@ -429,7 +429,7 @@ async def on_request_exception(
             exc_type = type(params.exception).__qualname__
             if _report_new(sem_conv_opt_in_mode):
                 trace_config_ctx.span.set_attribute(ERROR_TYPE, exc_type)
-                metric_attributes[ERROR_TYPE] = exc_type
+                trace_config_ctx.metric_attributes[ERROR_TYPE] = exc_type
 
             trace_config_ctx.span.set_status(
                 Status(StatusCode.ERROR, exc_type)
@@ -450,6 +450,7 @@ def _trace_config_ctx_factory(**kwargs):
             duration_histogram_old=duration_histogram_old,
             duration_histogram_new=duration_histogram_new,
             excluded_urls=excluded_urls,
+            metric_attributes={},
             **kwargs,
         )
 

instrumentation/opentelemetry-instrumentation-aiohttp-client/tests/test_aiohttp_client_integration.py

@@ -828,6 +828,56 @@ async def request_handler(request):
                     self._assert_spans([], 0)
                     self._assert_metrics(0)
 
+    def test_metric_attributes_isolation(self):
+        async def success_handler(request):
+            assert "traceparent" in request.headers
+            return aiohttp.web.Response(status=HTTPStatus.OK)
+
+        async def timeout_handler(request):
+            await asyncio.sleep(60)
+            assert "traceparent" in request.headers
+            return aiohttp.web.Response(status=HTTPStatus.OK)
+
+        trace_config: aiohttp.TraceConfig = (
+            aiohttp_client.create_trace_config()
+        )
+
+        success_host, success_port = self._http_request(
+            trace_config=trace_config,
+            url="/success",
+            request_handler=success_handler,
+        )
+
+        timeout_host, timeout_port = self._http_request(
+            trace_config=trace_config,
+            url="/timeout",
+            request_handler=timeout_handler,
+            timeout=aiohttp.ClientTimeout(sock_read=0.01),
+        )
+
+        metrics = self._assert_metrics(1)
+        duration_dp_attributes = [
+            dict(dp.attributes) for dp in metrics[0].data.data_points
+        ]
+        self.assertEqual(
+            [
+                {
+                    HTTP_METHOD: "GET",
+                    HTTP_HOST: success_host,
+                    HTTP_STATUS_CODE: int(HTTPStatus.OK),
+                    NET_PEER_NAME: success_host,
+                    NET_PEER_PORT: success_port,
+                },
+                {
+                    HTTP_METHOD: "GET",
+                    HTTP_HOST: timeout_host,
+                    NET_PEER_NAME: timeout_host,
+                    NET_PEER_PORT: timeout_port,
+                },
+            ],
+            duration_dp_attributes,
+        )
+
 
 class TestAioHttpClientInstrumentor(TestBase):
     URL = "/test-path"