Remove the DualStatsManager and the Stats interfaces by xBis7 · Pull Request #63932 · apache/airflow

xBis7 · 2026-03-19T14:02:17Z

This patch is removing the DualStatsManager and the Stats interfaces.

Action items

DualStatsManager
- Remove the DualStatsManager
- Move all the DualStatsManager logic under _shared/stats.py
- Rename the extra_tags parameters to legacy_name_tags
- Use more intuitive function names for the methods copied from the DualStatsManager
Stats
- Remove the metaclass
- Replace all metrics calls using the Stats class by calls using the stats module
- Convert all stats methods, incr, decr, gauge, etc. to module-level functions
- Use a module-level variable for holding the backend that will be used
  - We used to store the backend implementation to the Stats.instance class attribute
- Use a PID check to handle process forks
  - It used to check if the Stats.instance is None and then reinitialize
providers - back compat
- Add a Stats shim, to continue handling imports using sdk.py
- If Airflow >= 3.3
  - Use the new module-level functions stats.incr, stats.gauge, etc. through the Stats shim
  - The DualStatsManager logic exists under the new stats functions
  - Stats now has extra parameters for the DualStatsManager logic
- For previous version
  - Import and use the old Stats interface

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Claude Sonnet 4.6 Extended

Read the Pull Request Guidelines for more information. Note: commit author/co-author name and email in commits become permanently public when merged.
For fundamental code changes, an Airflow Improvement Proposal (AIP) is needed.
When adding dependency, check compliance with the ASF 3rd Party License Policy.
For significant user-facing changes create newsfragment: {pr_number}.significant.rst, in airflow-core/newsfragments. You can add this file in a follow-up commit after the PR is created so you know the PR number.

xBis7 · 2026-03-19T14:25:03Z

cc @dstandish @ashb @potiuk

dstandish

looks ok to me. can you summarize the potential backcompat issues?

xBis7 · 2026-03-20T18:06:41Z

can you summarize the potential backcompat issues?

@dstandish Any potential backcompat issues are with the providers. Because they have different versioning, the latest version could run against some version of airflow-core or task-sdk prior to 3.2, in which case they will need to import and use the old Stats... class.

ashb · 2026-04-30T12:43:37Z

🤞🏻

xBis7 · 2026-04-30T18:55:17Z

@ashb @jscheffl Thank you!

jscheffl · 2026-04-30T20:57:57Z

Wohoo! landed!

#protm

kacpermuda · 2026-05-04T11:59:13Z

Just FYI, the OL provider needed to be adjusted (#66351 ) after this change, we were using get_stats_factory, and the removal of arg that this function expected was a breaking change. I think it was the only place changed in this PR, where get_stats_factory is used in a provider, so hopefully no other places will be impacted.

xBis7 · 2026-05-04T12:33:45Z

@kacpermuda Sorry for the inconvenience. I didn't put much thought into it because the back compat CI step for 3.2.1 was green.

https://github.com/apache/airflow/actions/runs/25169748334/job/73789176552?pr=63932

kacpermuda · 2026-05-04T13:00:44Z

No problem, we caught that early, we should have had tests for that and now we'll add them, sounds like a win to me.

…g; backport fix for 3.2.x) (#68078) * Initialize Task SDK Stats in the API server so Edge Worker metrics are emitted The API server serves the Edge Worker REST API (/edge_worker/v1/...) whose heartbeat handler records edge_worker.* metrics through the Task SDK Stats singleton (resolved by the Edge provider via airflow.providers.common.compat). Unlike the scheduler, triggerer, dag-processor, executors and task runner, the API server never called Stats.initialize(...). After the auto-initializing Stats was removed in #63932, that singleton stays a NoStatsLogger in the API server process and every Edge Worker metric is silently dropped. Initialize the Task SDK Stats singleton from the FastAPI lifespan (runs once per worker, post-fork), mirroring the existing init in serde/task_runner. The call is guarded so a metrics misconfiguration can never block API server startup. Closes: #68077 Signed-off-by: Diogo Silva <diogo.silva@five9.com> * Add newsfragment for #68078 Signed-off-by: Diogo Silva <diogo.silva@five9.com> * fix: fix ruff errors * Remove newsfragment — bug fix does not require a user-facing changelog entry * Make API server Stats init log and docstring metric-agnostic * Update airflow-core/src/airflow/api_fastapi/app.py Co-authored-by: Jens Scheffler <95105677+jscheffl@users.noreply.github.com> * Update airflow-core/tests/unit/api_fastapi/test_app.py Co-authored-by: Jens Scheffler <95105677+jscheffl@users.noreply.github.com> --------- Signed-off-by: Diogo Silva <diogo.silva@five9.com> Co-authored-by: Jens Scheffler <95105677+jscheffl@users.noreply.github.com>

…g; backport fix for 3.2.x) (apache#68078) * Initialize Task SDK Stats in the API server so Edge Worker metrics are emitted The API server serves the Edge Worker REST API (/edge_worker/v1/...) whose heartbeat handler records edge_worker.* metrics through the Task SDK Stats singleton (resolved by the Edge provider via airflow.providers.common.compat). Unlike the scheduler, triggerer, dag-processor, executors and task runner, the API server never called Stats.initialize(...). After the auto-initializing Stats was removed in apache#63932, that singleton stays a NoStatsLogger in the API server process and every Edge Worker metric is silently dropped. Initialize the Task SDK Stats singleton from the FastAPI lifespan (runs once per worker, post-fork), mirroring the existing init in serde/task_runner. The call is guarded so a metrics misconfiguration can never block API server startup. Closes: apache#68077 Signed-off-by: Diogo Silva <diogo.silva@five9.com> * Add newsfragment for apache#68078 Signed-off-by: Diogo Silva <diogo.silva@five9.com> * fix: fix ruff errors * Remove newsfragment — bug fix does not require a user-facing changelog entry * Make API server Stats init log and docstring metric-agnostic * Update airflow-core/src/airflow/api_fastapi/app.py Co-authored-by: Jens Scheffler <95105677+jscheffl@users.noreply.github.com> * Update airflow-core/tests/unit/api_fastapi/test_app.py Co-authored-by: Jens Scheffler <95105677+jscheffl@users.noreply.github.com> --------- Signed-off-by: Diogo Silva <diogo.silva@five9.com> Co-authored-by: Jens Scheffler <95105677+jscheffl@users.noreply.github.com>

boring-cyborg Bot added area:CLI area:DAG-processing area:deadline-alerts AIP-86 (former AIP-57) area:Executors-core LocalExecutor & SequentialExecutor area:plugins area:providers area:Scheduler including HA (high availability) scheduler area:Triggerer provider:celery labels Mar 19, 2026

xBis7 force-pushed the simplify-stats branch 2 times, most recently from 0e5c7f8 to 91f408e Compare March 19, 2026 14:42

dstandish reviewed Mar 19, 2026

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Comment thread airflow-core/src/airflow/observability/stats.py Outdated

dstandish reviewed Mar 19, 2026

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Comment thread providers/edge3/src/airflow/providers/edge3/models/edge_worker.py Outdated

dstandish reviewed Mar 19, 2026

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Comment thread scripts/ci/prek/check_metrics_synced_with_the_registry.py

dstandish approved these changes Mar 19, 2026

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xBis7 force-pushed the simplify-stats branch from 7a86ddf to ed9a53c Compare March 20, 2026 13:49

xBis7 mentioned this pull request Mar 20, 2026

Cleanup the DualStatsManager and fix any leftover Stats calls #62705

Closed

2 tasks

xBis7 force-pushed the simplify-stats branch 5 times, most recently from 0c670de to 80c947b Compare March 30, 2026 07:33

xBis7 marked this pull request as ready for review March 30, 2026 16:14

xBis7 requested review from amoghrajesh, ashb, gopidesupavan, kaxil and potiuk as code owners March 30, 2026 16:15

xBis7 and others added 11 commits April 30, 2026 15:33

make timer() return TimerProtocol

63ddcee

update serialization/definitions/dag after rebase

a58b5ab

remove 'Stats.' from airflow-core test_stats

c790aa8

update Stats.initialize in the openlineage listener

4d6d21c

replace . with __ when replacing variables in legacy names

d7e2dbf

fix failures in test_triggerer_job.py after rebase

1792287

cleanup openlineage listener.py

40f53bb

provide a spec in all backend mocks in tests

8360b79

fix test_triggerer_job after rebase

bb7e83f

Addressing minor code review directly

316f612

remove unused import after rebase

1658e0e

xBis7 force-pushed the simplify-stats branch from fe10df4 to 1658e0e Compare April 30, 2026 12:35

xBis7 added 2 commits April 30, 2026 16:45

fix mypy error in shared/observability

1caaf88

fix mypy error + observability tests

1193e14

ashb merged commit 67bab4a into apache:main Apr 30, 2026
143 checks passed

xBis7 deleted the simplify-stats branch April 30, 2026 18:55

kacpermuda mentioned this pull request May 4, 2026

fix: Prevent stats from breaking executor initializer #66351

Merged

1 task

vincbeck mentioned this pull request May 6, 2026

Status of testing Providers that were prepared on May 06, 2026 #66480

Closed

79 tasks

jscheffl mentioned this pull request May 23, 2026

Bring back edge worker metric compatibility with Airflow 3.2 #67328

Open

This was referenced Jun 5, 2026

Edge Worker metrics silently dropped: API server never initializes Task SDK Stats (regression of #63932) #68077

Closed

Explicitly initialize Task SDK Stats in API server lifespan (hardening; backport fix for 3.2.x) #68078

Merged

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Remove the DualStatsManager and the Stats interfaces#63932

Remove the DualStatsManager and the Stats interfaces#63932
ashb merged 52 commits into
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