[PR #20889] [CLOSED] fix: fix aiohttp session leak in streaming responses #41442

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GiteaMirror · 2026-04-25T13:41:33-05:00

GiteaMirror commented

2026-04-25 13:41:33 -05:00

📋 Pull Request Information

Original PR: https://github.com/open-webui/open-webui/pull/20889
Author: @Classic298
Created: 1/23/2026
Status: ❌ Closed

Base: dev ← Head: aiohttp

📝 Commits (1)

cd515e6 fix: fix aiohttp session leak in ollama router (#144)

📊 Changes

2 files changed (+32 additions, -19 deletions)

View changed files

📝 backend/open_webui/routers/ollama.py (+17 -6)
📝 backend/open_webui/routers/openai.py (+15 -13)

📄 Description

Summary

Fixes "Unclosed client session" errors that occur when aiohttp sessions are not properly closed during streaming responses.

Root cause: BackgroundTask cleanup is unreliable - it doesn't execute when clients disconnect during streaming, causing session leaks that accumulate over time.

Solution: Replace BackgroundTask with a stream_wrapper async generator that guarantees cleanup in its finally block, which executes even when streaming is interrupted.

Changes

openai.py

Add stream_wrapper() function for reliable session cleanup
Update chat_completion_handler(), embeddings(), and proxy() to use stream_wrapper instead of BackgroundTask
Remove unused BackgroundTask import

ollama.py

Add stream_wrapper() function for reliable session cleanup
Update send_post_request() to use stream_wrapper instead of BackgroundTask
Initialize session = None to prevent potential UnboundLocalError
Add streaming variable to track actual streaming state (previously used stream parameter incorrectly)
Remove unused BackgroundTask import

Contributor License Agreement

By submitting this pull request, I confirm that I have read and fully agree to the Contributor License Agreement (CLA), and I am providing my contributions under its terms.

Note

Deleting the CLA section will lead to immediate closure of your PR and it will not be merged in.

_{🔄 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/20889 **Author:** [@Classic298](https://github.com/Classic298) **Created:** 1/23/2026 **Status:** ❌ Closed **Base:** `dev` ← **Head:** `aiohttp` --- ### 📝 Commits (1) - [`cd515e6`](https://github.com/open-webui/open-webui/commit/cd515e6dd53d26362335a4b20405077d57f767cb) fix: fix aiohttp session leak in ollama router (#144) ### 📊 Changes **2 files changed** (+32 additions, -19 deletions) <details> <summary>View changed files</summary> 📝 `backend/open_webui/routers/ollama.py` (+17 -6) 📝 `backend/open_webui/routers/openai.py` (+15 -13) </details> ### 📄 Description # Summary Fixes "Unclosed client session" errors that occur when aiohttp sessions are not properly closed during streaming responses. Root cause: BackgroundTask cleanup is unreliable - it doesn't execute when clients disconnect during streaming, causing session leaks that accumulate over time. Solution: Replace BackgroundTask with a stream_wrapper async generator that guarantees cleanup in its finally block, which executes even when streaming is interrupted. ### Changes **openai.py** 1. Add stream_wrapper() function for reliable session cleanup 2. Update chat_completion_handler(), embeddings(), and proxy() to use stream_wrapper instead of BackgroundTask 3. Remove unused BackgroundTask import **ollama.py** 1. Add stream_wrapper() function for reliable session cleanup 2. Update send_post_request() to use stream_wrapper instead of BackgroundTask 3. Initialize session = None to prevent potential UnboundLocalError 4. Add streaming variable to track actual streaming state (previously used stream parameter incorrectly) 5. Remove unused BackgroundTask import ### Contributor License Agreement By submitting this pull request, I confirm that I have read and fully agree to the [Contributor License Agreement (CLA)](https://github.com/open-webui/open-webui/blob/main/CONTRIBUTOR_LICENSE_AGREEMENT), and I am providing my contributions under its terms. > [!NOTE] > Deleting the CLA section will lead to immediate closure of your PR and it will not be merged in. --- <sub>🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.</sub>

GiteaMirror added the pull-request label 2026-04-25 13:41:33 -05:00

GiteaMirror closed this issue

2026-04-25 13:41:35 -05:00

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Reference: github-starred/open-webui#41442