fix(logging): Fix deadlock in log batcher#5684
Merged
sentrivana merged 8 commits intomasterfrom Mar 17, 2026
Merged
Conversation
Contributor
Semver Impact of This PR🟢 Patch (bug fixes) 📋 Changelog PreviewThis is how your changes will appear in the changelog. New Features ✨Anthropic
Pydantic Ai
Other
Bug Fixes 🐛
Documentation 📚
Internal Changes 🔧Anthropic
Docs
Openai Agents
Other
🤖 This preview updates automatically when you update the PR. |
Contributor
Codecov Results 📊✅ 134 passed | Total: 134 | Pass Rate: 100% | Execution Time: 20.60s All tests are passing successfully. ❌ Patch coverage is 2.56%. Project has 13572 uncovered lines. Files with missing lines (2)
Generated by Codecov Action |
Contributor
Codecov Results 📊✅ 52 passed | Total: 52 | Pass Rate: 100% | Execution Time: 6.78s All tests are passing successfully. ❌ Patch coverage is 5.56%. Project has 15300 uncovered lines. Files with missing lines (1)
Generated by Codecov Action |
![sentry-warden[bot]](https://avatars.githubusercontent.com/in/2755838?s=60&v=4){kind=small}
![cursor[bot]](https://avatars.githubusercontent.com/in/1210556?s=60&v=4){kind=small}
There was a problem hiding this comment.
Cursor Bugbot has reviewed your changes and found 1 potential issue.
Bugbot Autofix prepared a fix for the issue found in the latest run.
- ✅ Fixed: flush() unconditionally clears re-entry guard flag
- Batcher.flush() now preserves and restores the thread-local re-entry flag instead of unconditionally clearing it, and a regression test covers this case.
Or push these changes by commenting:
@cursor push 4fe16a2160
Preview (4fe16a2160)
diff --git a/sentry_sdk/_batcher.py b/sentry_sdk/_batcher.py
--- a/sentry_sdk/_batcher.py
+++ b/sentry_sdk/_batcher.py
@@ -115,11 +115,12 @@
self._flusher = None
def flush(self) -> None:
+ old_flag = getattr(self._active, "flag", False)
self._active.flag = True
try:
self._flush()
finally:
- self._active.flag = False
+ self._active.flag = old_flag
def _add_to_envelope(self, envelope: "Envelope") -> None:
envelope.add_item(
diff --git a/tests/test_batcher.py b/tests/test_batcher.py
new file mode 100644
--- /dev/null
+++ b/tests/test_batcher.py
@@ -1,0 +1,28 @@
+from sentry_sdk._batcher import Batcher
+
+
+class DummyBatcher(Batcher[int]):
+ def __init__(self) -> None:
+ super().__init__(
+ capture_func=lambda envelope: None,
+ record_lost_func=lambda *args, **kwargs: None,
+ )
+ self.flush_calls = 0
+
+ def _flush(self):
+ self.flush_calls += 1
+ return None
+
+ @staticmethod
+ def _to_transport_format(item):
+ return item
+
+
+def test_flush_restores_existing_reentry_guard():
+ batcher = DummyBatcher()
+ batcher._active.flag = True
+
+ batcher.flush()
+
+ assert batcher._active.flag is True
+ assert batcher.flush_calls == 1This Bugbot Autofix run was free. To enable autofix for future PRs, go to the Cursor dashboard.
![sentry[bot]](https://avatars.githubusercontent.com/in/12637?s=60&v=4){kind=small}
sentrivana
commented
Mar 17, 2026
|
|
||
|
|
||
| @minimum_python_37 | ||
| @pytest.mark.timeout(5) |
Contributor
Author
There was a problem hiding this comment.
This will actually make the test fail after 5s if it gets deadlocked. Tested on master.
alexander-alderman-webb
approved these changes
Mar 17, 2026
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Description
In certain scenarios, the SDK's log batcher might cause a deadlock. This happens if it's currently flushing, and during the flush, something emits a log that we try to capture and add to the (locked) batcher.
With this PR, we're adding a re-entry guard to the batcher, preventing it from recursively handling log items during locked code paths like
flush().Issues
Closes #5681
Reminders
tox -e linters.feat:,fix:,ref:,meta:)