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fix(langchain): langgraph application crash due to context detach #3256

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Merged
galkleinman merged 2 commits into from
Aug 14, 2025
Merged

fix(langchain): langgraph application crash due to context detach #3256

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3666eaf
fix(langchain): langgraph application crash due to context detach
galkleinman Aug 14, 2025
8caba09
lint
galkleinman Aug 14, 2025
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11 changes: 8 additions & 3 deletions ...entelemetry-instrumentation-langchain/opentelemetry/instrumentation/langchain/__init__.py
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Original file line number Diff line number Diff line change
Expand Up @@ -242,8 +242,13 @@ def __call__(

# In legacy chains like LLMChain, suppressing model instrumentations
# within create_llm_span doesn't work, so this should helps as a fallback
context_api.attach(
context_api.set_value(SUPPRESS_LANGUAGE_MODEL_INSTRUMENTATION_KEY, True)
)
try:
context_api.attach(
context_api.set_value(SUPPRESS_LANGUAGE_MODEL_INSTRUMENTATION_KEY, True)
)
except Exception:
# If context setting fails, continue without suppression
# This is not critical for core functionality
pass

return wrapped(*args, **kwargs)
104 changes: 80 additions & 24 deletions ...try-instrumentation-langchain/opentelemetry/instrumentation/langchain/callback_handler.py
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Original file line number Diff line number Diff line change
Expand Up @@ -187,18 +187,57 @@ def _end_span(self, span: Span, run_id: UUID) -> None:
span.end()
token = self.spans[run_id].token
if token:
try:
# Use the runtime context directly to avoid logging from context_api.detach()
from opentelemetry.context import _RUNTIME_CONTEXT
_RUNTIME_CONTEXT.detach(token)
except (ValueError, RuntimeError, Exception):
# Context detach can fail in async scenarios when tokens are created in different contexts
# This includes ValueError, RuntimeError, and other context-related exceptions
# This is expected behavior and doesn't affect the correct span hierarchy
pass
self._safe_detach_context(token)

del self.spans[run_id]

def _safe_attach_context(self, span: Span):
"""
Safely attach span to context, handling potential failures in async scenarios.

Returns the context token for later detachment, or None if attachment fails.
"""
try:
return context_api.attach(set_span_in_context(span))
except Exception:
# Context attachment can fail in some edge cases, particularly in
# complex async scenarios or when context is corrupted.
# Return None to indicate no token needs to be detached later.
return None

def _safe_detach_context(self, token):
"""
Safely detach context token without causing application crashes.

This method implements a fail-safe approach to context detachment that handles
all known edge cases in async/concurrent scenarios where context tokens may
become invalid or be detached in different execution contexts.

We use the runtime context directly to avoid logging errors from context_api.detach()
"""
if not token:
return

try:
# Use the runtime context directly to avoid error logging from context_api.detach()
from opentelemetry.context import _RUNTIME_CONTEXT

_RUNTIME_CONTEXT.detach(token)
except Exception:
# Context detach can fail in async scenarios when tokens are created in different contexts
# This includes ValueError, RuntimeError, and other context-related exceptions
# This is expected behavior and doesn't affect the correct span hierarchy
#
# Common scenarios where this happens:
# 1. Token created in one async task/thread, detached in another
# 2. Context was already detached by another process
# 3. Token became invalid due to context switching
# 4. Race conditions in highly concurrent scenarios
#
# This is safe to ignore as the span itself was properly ended
# and the tracing data is correctly captured.
pass

Comment on lines +208 to +240
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@coderabbitai coderabbitai Bot Aug 14, 2025

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🛠️ Refactor suggestion

Prefer contextlib.suppress and avoid relying solely on private _RUNTIME_CONTEXT.

Using a private API may break across OTel versions. Try context_api.detach first, then fall back to _RUNTIME_CONTEXT only if needed. Also adopt contextlib.suppress to satisfy linting and reduce noise.

-    def _safe_detach_context(self, token):
+    def _safe_detach_context(self, token: Optional[object]) -> None:
@@
-        try:
-            # Use the runtime context directly to avoid error logging from context_api.detach()
-            from opentelemetry.context import _RUNTIME_CONTEXT
-
-            _RUNTIME_CONTEXT.detach(token)
-        except Exception:
-            # Context detach can fail in async scenarios when tokens are created in different contexts
-            # This includes ValueError, RuntimeError, and other context-related exceptions
-            # This is expected behavior and doesn't affect the correct span hierarchy
-            #
-            # Common scenarios where this happens:
-            # 1. Token created in one async task/thread, detached in another
-            # 2. Context was already detached by another process
-            # 3. Token became invalid due to context switching
-            # 4. Race conditions in highly concurrent scenarios
-            #
-            # This is safe to ignore as the span itself was properly ended
-            # and the tracing data is correctly captured.
-            pass
+        # Attempt a normal detach first; fall back to runtime context if needed.
+        with contextlib.suppress(Exception):
+            context_api.detach(token)
+            return
+        with contextlib.suppress(Exception):
+            from opentelemetry.context import _RUNTIME_CONTEXT  # type: ignore
+            _RUNTIME_CONTEXT.detach(token)

Committable suggestion skipped: line range outside the PR's diff.

def _create_span(
self,
run_id: UUID,
Expand All @@ -220,12 +259,17 @@ def _create_span(
for k, v in metadata.items()
if v is not None
}
context_api.attach(
context_api.set_value(
"association_properties",
{**current_association_properties, **sanitized_metadata},
try:
context_api.attach(
context_api.set_value(
"association_properties",
{**current_association_properties, **sanitized_metadata},
)
)
)
except Exception:
# If setting association properties fails, continue without them
# This doesn't affect the core span functionality
pass
Comment on lines +262 to +272
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@coderabbitai coderabbitai Bot Aug 14, 2025

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🛠️ Refactor suggestion

Replace try/except/pass with contextlib.suppress and retain the token for later detach (Ruff SIM105).

This aligns with lint guidance and prevents leaking association_properties in the runtime context beyond the span lifecycle.

Apply this diff:

-            try:
-                context_api.attach(
-                    context_api.set_value(
-                        "association_properties",
-                        {**current_association_properties, **sanitized_metadata},
-                    )
-                )
-            except Exception:
-                # If setting association properties fails, continue without them
-                # This doesn't affect the core span functionality
-                pass
+            with contextlib.suppress(Exception):
+                assoc_token = context_api.attach(
+                    context_api.set_value(
+                        "association_properties",
+                        {**current_association_properties, **sanitized_metadata},
+                    )
+                )
+                if assoc_token is not None:
+                    self._association_tokens[run_id] = assoc_token
📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
try:
context_api.attach(
context_api.set_value(
"association_properties",
{**current_association_properties, **sanitized_metadata},
)
)
)
except Exception:
# If setting association properties fails, continue without them
# This doesn't affect the core span functionality
pass
with contextlib.suppress(Exception):
assoc_token = context_api.attach(
context_api.set_value(
"association_properties",
{**current_association_properties, **sanitized_metadata},
)
)
if assoc_token is not None:
self._association_tokens[run_id] = assoc_token
🧰 Tools
🪛 Ruff (0.12.2)

262-272: Use contextlib.suppress(Exception) instead of try-except-pass

(SIM105)

🤖 Prompt for AI Agents 
In
packages/opentelemetry-instrumentation-langchain/opentelemetry/instrumentation/langchain/callback_handler.py
around lines 262-272, replace the bare try/except/pass with contextlib.suppress
while capturing the token returned by context_api.attach so it can be detached
later; specifically, import contextlib, use contextlib.suppress(Exception)
around the context_api.attach(...) call and assign its return to a variable
(e.g., token = context_api.attach(...)) and ensure that elsewhere after the span
lifecycle you call context_api.detach(token) to avoid leaking
association_properties in the runtime context beyond the span.


if parent_run_id is not None and parent_run_id in self.spans:
span = self.tracer.start_span(
Expand All @@ -236,7 +280,7 @@ def _create_span(
else:
span = self.tracer.start_span(span_name, kind=kind)

token = context_api.attach(set_span_in_context(span))
token = self._safe_attach_context(span)

_set_span_attribute(span, SpanAttributes.TRACELOOP_WORKFLOW_NAME, workflow_name)
_set_span_attribute(span, SpanAttributes.TRACELOOP_ENTITY_PATH, entity_path)
Expand Down Expand Up @@ -317,9 +361,13 @@ def _create_llm_span(

# we already have an LLM span by this point,
# so skip any downstream instrumentation from here
token = context_api.attach(
context_api.set_value(SUPPRESS_LANGUAGE_MODEL_INSTRUMENTATION_KEY, True)
)
try:
token = context_api.attach(
context_api.set_value(SUPPRESS_LANGUAGE_MODEL_INSTRUMENTATION_KEY, True)
)
except Exception:
# If context setting fails, continue without suppression token
token = None

self.spans[run_id] = SpanHolder(
span, token, None, [], workflow_name, None, entity_path
Expand Down Expand Up @@ -411,11 +459,15 @@ def on_chain_end(

self._end_span(span, run_id)
if parent_run_id is None:
context_api.attach(
context_api.set_value(
SUPPRESS_LANGUAGE_MODEL_INSTRUMENTATION_KEY, False
try:
context_api.attach(
context_api.set_value(
SUPPRESS_LANGUAGE_MODEL_INSTRUMENTATION_KEY, False
)
)
)
except Exception:
# If context reset fails, it's not critical for functionality
pass

@dont_throw
def on_chat_model_start(
Expand Down Expand Up @@ -513,8 +565,12 @@ def on_llm_end(
if model_name is None:
model_name = extract_model_name_from_response_metadata(response)
if model_name is None and hasattr(context_api, "get_value"):
association_properties = context_api.get_value("association_properties") or {}
model_name = _extract_model_name_from_association_metadata(association_properties)
association_properties = (
context_api.get_value("association_properties") or {}
)
model_name = _extract_model_name_from_association_metadata(
association_properties
)
token_usage = (response.llm_output or {}).get("token_usage") or (
response.llm_output or {}
).get("usage")
Expand Down