OTEL observable-gauge callbacks run on the PeriodicExportingMetricReader thread, which has no event loop. The three async callbacks in utils/telemetry/metrics.py (observe_active_users, observe_total_registered_users, observe_users_active_today) returned coroutines instead of iterables of Observation, causing TypeError: 'coroutine' object is not iterable on every export cycle.
This PR:
Adds sync COUNT(*) variants on UsersTable (get_num_users_sync, get_active_user_count_sync, get_num_users_active_today_sync) using the existing sync SessionLocal from open_webui/internal/db.py.
Converts the three OTEL callbacks back to plain def and points them at the new sync methods.
Sync SessionLocal is documented in db.py as "used ONLY for startup config loading"; OTEL metric callbacks are the one legitimate runtime exception because OTel's PeriodicExportingMetricReader runs them on a worker thread outside any event loop. Option 2 (asyncio.run_coroutine_threadsafe against the captured main loop) was considered but would require a lifespan hook plus cross-thread scheduling per export, with no runtime advantage for metrics polled every ~30s.
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🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.
## 📋 Pull Request Information
**Original PR:** https://github.com/open-webui/open-webui/pull/24046
**Author:** [@franciseliang99-dot](https://github.com/franciseliang99-dot)
**Created:** 4/23/2026
**Status:** ❌ Closed
**Base:** `dev` ← **Head:** `fix/otel-metrics-sync-callbacks`
---
### 📝 Commits (1)
- [`fe8fcf3`](https://github.com/open-webui/open-webui/commit/fe8fcf313569ffc43fd8d1274f09a5d285a328e2) fix(telemetry): run OTEL metric callbacks synchronously
### 📊 Changes
**2 files changed** (+35 additions, -8 deletions)
<details>
<summary>View changed files</summary>
📝 `backend/open_webui/models/users.py` (+23 -1)
📝 `backend/open_webui/utils/telemetry/metrics.py` (+12 -7)
</details>
### 📄 Description
OTEL observable-gauge callbacks run on the `PeriodicExportingMetricReader` thread, which has no event loop. The three async callbacks in `utils/telemetry/metrics.py` (`observe_active_users`, `observe_total_registered_users`, `observe_users_active_today`) returned coroutines instead of iterables of `Observation`, causing `TypeError: 'coroutine' object is not iterable` on every export cycle.
This PR:
- Adds sync `COUNT(*)` variants on `UsersTable` (`get_num_users_sync`, `get_active_user_count_sync`, `get_num_users_active_today_sync`) using the existing sync `SessionLocal` from `open_webui/internal/db.py`.
- Converts the three OTEL callbacks back to plain `def` and points them at the new sync methods.
Sync `SessionLocal` is documented in `db.py` as "used ONLY for startup config loading"; OTEL metric callbacks are the one legitimate runtime exception because OTel's `PeriodicExportingMetricReader` runs them on a worker thread outside any event loop. Option 2 (`asyncio.run_coroutine_threadsafe` against the captured main loop) was considered but would require a lifespan hook plus cross-thread scheduling per export, with no runtime advantage for metrics polled every ~30s.
Closes #23936
Closes #23938
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---
<sub>🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.</sub>
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📋 Pull Request Information
Original PR: https://github.com/open-webui/open-webui/pull/24046
Author: @franciseliang99-dot
Created: 4/23/2026
Status: ❌ Closed
Base:
dev← Head:fix/otel-metrics-sync-callbacks📝 Commits (1)
fe8fcf3fix(telemetry): run OTEL metric callbacks synchronously📊 Changes
2 files changed (+35 additions, -8 deletions)
View changed files
📝
backend/open_webui/models/users.py(+23 -1)📝
backend/open_webui/utils/telemetry/metrics.py(+12 -7)📄 Description
OTEL observable-gauge callbacks run on the
PeriodicExportingMetricReaderthread, which has no event loop. The three async callbacks inutils/telemetry/metrics.py(observe_active_users,observe_total_registered_users,observe_users_active_today) returned coroutines instead of iterables ofObservation, causingTypeError: 'coroutine' object is not iterableon every export cycle.This PR:
COUNT(*)variants onUsersTable(get_num_users_sync,get_active_user_count_sync,get_num_users_active_today_sync) using the existing syncSessionLocalfromopen_webui/internal/db.py.defand points them at the new sync methods.Sync
SessionLocalis documented indb.pyas "used ONLY for startup config loading"; OTEL metric callbacks are the one legitimate runtime exception because OTel'sPeriodicExportingMetricReaderruns them on a worker thread outside any event loop. Option 2 (asyncio.run_coroutine_threadsafeagainst the captured main loop) was considered but would require a lifespan hook plus cross-thread scheduling per export, with no runtime advantage for metrics polled every ~30s.Closes #23936
Closes #23938
Contributor License Agreement
🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.