Added error correlation headers. by danielmorell · Pull Request #491 · rollbar/pyrollbar

danielmorell · 2026-03-13T23:30:41Z

Description of the change

Adds support for the baggage request header, enabling propagation of rollbar.session.id and rollbar.execution.scope.id.

Frameworks included are:

Django
FastAPI
Flask
Pyramid
Starlette

The session_id attribute is persisted across the entire request. Every log message, trace, or exception reported will include the same session_id.

If the baggage hearder is not included in a request, a new session_id will be generated, and will persist for the lifecycle of the request.

The session_id is stored in either thread local or an async safe contextvar depending on the framework.

Type of change

Bug fix (non-breaking change that fixes an issue)
New feature (non-breaking change that adds functionality)
Breaking change (fix or feature that would cause existing functionality to not work as expected)
Maintenance
New release

Related issues

SDK-578

Checklists

Development

Lint rules pass locally
The code changed/added as part of this pull request has been covered with tests
All tests related to the changed code pass in development

Code review

This pull request has a descriptive title and information useful to a reviewer. There may be a screenshot or screencast attached
"Ready for review" label attached to the PR and reviewers assigned
Issue from task tracker has a link to this pull request
Changes have been reviewed by at least one other engineer

waltjones · 2026-03-16T18:16:43Z

rollbar/contrib/pyramid/__init__.py

@@ -51,6 +53,7 @@ def rollbar_tween_factory(pyramid_handler, registry):

    def rollbar_tween(request):
        # for testing out the integration


Looks like this comment got separated from the try block it references.

waltjones · 2026-03-16T18:32:02Z

rollbar/lib/session.py

+            break
+
+    if not baggage_header:
+        return _build_new_session_attributes()


This layer should not try to create a session id if not present in the header.

cc @shankj3

Ah yes, when I updated the ticket & dmed you I included that change, apologies for not calling it out more:

If a baggage header is not present, one should be created, and a rollbar.execution.scope.id should be created as a hex representation of a 128 bit number. If rollbar.session.id is not present, the key should not be created.

It'd be the rollbar.execution.scope.id that would be created on the fly, rollbar.session.id can be null

This has been updated to generate rollbar.execution.scope.id instead of rollbar.session.id. I also updated the logic to always create rollbar.execution.scope.id even if rollbar.session.id exists but rollbar.execution.scope.id does not. This was not the case previously.

waltjones · 2026-03-16T19:36:40Z

rollbar/__init__.py

+    request = _session_data_from_request(data)
+    if request is None:
+        return
+    set_current_session(request.get('headers', None))


It looks like we get here because no middleware had set a current session, but the request is present via the rollbar payload, so we look at the headers there. That makes sense, though I'm curious whether this is to cover unsupported frameworks, or supported ones when the middleware wasn't installed.

I think calling set_current_session here introduces a bug though. Unlike in the middleware, nothing calls reset_current_session, and on the next request (from a different session) get_current_session above will succeed with the stale session that was set here.

This can be avoided if session.py provides a method to return the session_data from the headers without needing to set and get current session.

That makes sense. I have updated this, as well as added some logic to prevent overwriting any existing attributes. This is mostly to prevent bugs incase our future selves don't notice we were completely overwriting the data['attributes'] key.

waltjones · 2026-03-16T19:46:29Z

rollbar/contrib/starlette/requests.py

+            headers = request.get('headers', {})
+        elif hasattr(request, 'headers'):
+            headers = request.headers
+        set_current_session(headers)


Ideally this could go in middleware.py, allowing reset_current_session to be used, and keeping the responsibility of store_current_request more focused.

This function already returns request, so it seems straightforward to move this logic.

I have moved it to asgi/middleware.py as well as starlette/middleware.py so that it can apply to all ASGI frameworks that utilize the middleware.

waltjones · 2026-03-16T19:48:42Z

@danielmorell nice PR! I'll defer to @shankj3 on approval.

shankj3

This is looking great, thanks Daniel! If we can address the potential bugs and remove the creation of session ids in favor the the execution scope id, I think we'll be ready to ship.

Will the request interception be in a separate PR?

… data attributes.

shankj3 · 2026-03-23T20:23:24Z

rollbar/test/flask_tests/test_flask.py

@@ -9,6 +9,7 @@
 from unittest import mock


One thing I noticed when testing flask, we don't actually hook into the request lifecycle. So for my test route, which looks like this

@app.route("/boom_nested") def boom_nested(): from nested_error import raise_error rollbar.report_message("Running a message") raise_error()

If no baggage headers are passed, the execution id for the message here, then the exception thrown from raise-error, are different, even though they are in the same execution context.

What do you think about providing a new function for flask config, that would take in the flask app as an argument then hook into app.before_request and app.teardown_request? Then we could use the same logic as other frameworks, with set_current_session and reset_current_session

shankj3 · 2026-03-23T20:47:36Z

rollbar/test/fastapi_tests/test_middleware.py

I'm also seeing the same problem as with flask, where if you don't pass baggage headers, the rollbar.execution.scope.id is different for each error within a request. This was my little test app, it might be missing something:

import os import rollbar from fastapi import FastAPI from rollbar.contrib.fastapi import add_to rollbar.init( access_token=os.getenv("ROLLBAR_TOKEN", "POST_SERVER_ITEM_ACCESS_TOKEN"), environment=os.getenv("ROLLBAR_ENV", "development"), ) app = FastAPI(title="rollbar-fastapi-test") add_to(app) @app.get("/boom_nested") async def boom_nested(): from nested_error import raise_error rollbar.report_message("Error") # has a different request.execution.scope.id raise_error() # raises exc that has a different request.execution.scope.id

shankj3 · 2026-03-23T21:09:20Z

rollbar/test/flask_tests/test_flask.py

            self.app = create_app()
            init_rollbar(self.app)
            self.client = self.app.test_client()
+            reset_current_session()


Why do we need to reset current session? Is something leaking between requests?

shankj3 · 2026-03-25T17:30:18Z

rollbar/lib/session.py

+        return _build_new_scope_attributes()
+
+    # Always ensure we have an execution scope ID, even if the baggage header is present but doesn't contain it.
+    if not has_scope_id:


One last comment here - we should move this out of the core session code, and into the middleware. The reason for this is that we want a single rollbar.execution.scope.id for the lifespan of a request, and in the future, forwarded to other outgoing requests.

If the originating request does'nt have the rollbar.execution.scope.id, then this will be a unique value for every rollbar message sent as the request is processed, which doesn't give us much of a signal.

If this scope id was built once, in the middleware when a request is received and saved to thread / async storage, then we will get that signal.

danielmorell added 3 commits March 13, 2026 18:23

Added error correlation headers.

0da67fc

Removed call to removed Django HttpRequest method.

b544d5a

Fixed Django HttpRequest baggage test.

c535a01

danielmorell requested a review from brianr March 14, 2026 00:43

brianr requested review from shankj3 and waltjones March 14, 2026 02:03

waltjones reviewed Mar 16, 2026

View reviewed changes

shankj3 requested changes Mar 19, 2026

View reviewed changes

brianr removed their request for review March 20, 2026 20:00

danielmorell added 4 commits March 20, 2026 21:38

Moved session baggage header processing to ASGI middleware.

ba197da

Exported header parse method, and make sure not to overwrite existing…

5b7bc09

… data attributes.

Fixed comment location.

1c8d88e

Generate execution.scope.id if missing not session.id.

063a24a

danielmorell requested review from shankj3 and waltjones March 20, 2026 20:46

Explicitly set session data in Starlette middleware.

7686970

shankj3 reviewed Mar 23, 2026

View reviewed changes

shankj3 reviewed Mar 25, 2026

View reviewed changes

		@@ -51,6 +53,7 @@ def rollbar_tween_factory(pyramid_handler, registry):

		def rollbar_tween(request):
		# for testing out the integration

Conversation

danielmorell commented Mar 13, 2026

Description of the change

Type of change

Related issues

Checklists

Development

Code review

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

shankj3 Mar 17, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

waltjones commented Mar 16, 2026

Uh oh!

shankj3 left a comment

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

shankj3 Mar 17, 2026 •

edited

Loading