[PR #21573] [CLOSED] Fix: pip install lock for multiple worker instances #49191

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GiteaMirror · 2026-04-30T01:30:58-05:00

GiteaMirror commented

2026-04-30 01:30:58 -05:00

📋 Pull Request Information

Original PR: https://github.com/open-webui/open-webui/pull/21573
Author: @jmleksan
Created: 2/18/2026
Status: ❌ Closed

Base: dev ← Head: fix/pip-install-lock

📝 Commits (10+)

fe6783c Merge pull request #19030 from open-webui/dev
fc05e0a Merge pull request #19405 from open-webui/dev
e3faec6 Merge pull request #19416 from open-webui/dev
9899293 Merge pull request #19448 from open-webui/dev
140605e Merge pull request #19462 from open-webui/dev
6f1486f Merge pull request #19466 from open-webui/dev
bc599ae elastic
d95f533 Merge pull request #19729 from open-webui/dev
a727153 0.6.43 (#20093)
6adde20 Merge pull request #20394 from open-webui/dev

📊 Changes

2 files changed (+23 additions, -0 deletions)

View changed files

📝 backend/open_webui/utils/plugin.py (+22 -0)
📝 backend/requirements.txt (+1 -0)

📄 Description

Pull Request Checklist

This is to ensure large feature PRs are discussed with the community first, before starting work on it. If the community does not want this feature or it is not relevant for Open WebUI as a project, it can be identified in the discussion before working on the feature and submitting the PR.

Before submitting, make sure you've checked the following:

Target branch: Verify that the pull request targets the dev branch. PRs targeting main will be immediately closed.
Description: Provide a concise description of the changes made in this pull request down below.
Changelog: Ensure a changelog entry following the format of Keep a Changelog is added at the bottom of the PR description.
Documentation: Add docs in Open WebUI Docs Repository. Document user-facing behavior, environment variables, public APIs/interfaces, or deployment steps.
Dependencies: Are there any new or upgraded dependencies? If so, explain why, update the changelog/docs, and include any compatibility notes. Actually run the code/function that uses updated library to ensure it doesn't crash.
Testing: Perform manual tests to verify the implemented fix/feature works as intended AND does not break any other functionality. Include reproducible steps to demonstrate the issue before the fix. Test edge cases (URL encoding, HTML entities, types). Take this as an opportunity to make screenshots of the feature/fix and include them in the PR description.
Agentic AI Code: Confirm this Pull Request is not written by any AI Agent or has at least gone through additional human review AND manual testing. If any AI Agent is the co-author of this PR, it may lead to immediate closure of the PR.
Code review: Have you performed a self-review of your code, addressing any coding standard issues and ensuring adherence to the project's coding standards?
Design & Architecture: Prefer smart defaults over adding new settings; use local state for ephemeral UI logic. Open a Discussion for major architectural or UX changes.
Git Hygiene: Keep PRs atomic (one logical change). Clean up commits and rebase on dev to ensure no unrelated commits (e.g. from main) are included. Push updates to the existing PR branch instead of closing and reopening.
Title Prefix: To clearly categorize this pull request, prefix the pull request title using one of the following:
- BREAKING CHANGE: Significant changes that may affect compatibility
- build: Changes that affect the build system or external dependencies
- ci: Changes to our continuous integration processes or workflows
- chore: Refactor, cleanup, or other non-functional code changes
- docs: Documentation update or addition
- feat: Introduces a new feature or enhancement to the codebase
- fix: Bug fix or error correction
- i18n: Internationalization or localization changes
- perf: Performance improvement
- refactor: Code restructuring for better maintainability, readability, or scalability
- style: Changes that do not affect the meaning of the code (white space, formatting, missing semi-colons, etc.)
- test: Adding missing tests or correcting existing tests
- WIP: Work in progress, a temporary label for incomplete or ongoing work

Changelog Entry

Description

Fixes race condition in multi-worker deployments where concurrent pip package installations cause AssertionError when multiple workers attempt to install function/tool requirements simultaneously. Adds file-based locking to serialize pip install operations across workers.

Added

FileLock-based synchronization for pip install operations to prevent concurrent installations across multiple workers

Changed

Pip install operations now use a file lock (/tmp/open-webui-pip-install.lock) to ensure only one worker installs packages at a time

Fixed

Race condition causing AssertionError: Multiple workers attempting concurrent pip installations now serialize using FileLock, preventing crashes in multi-worker deployments (e.g., UVICORN_WORKERS > 1)

Additional Information

Problem:
In multi-worker deployments (e.g.,UVICORN_WORKERS > 1), when multiple workers start simultaneously or when functions/tools are loaded concurrently, each worker attempts to install pip packages independently. This causes AssertionError: Multiple processes are trying to acquire the lock because pip's internal locking mechanism detects concurrent install attempts.

Solution:
FileLock serialization: Added filelock library to serialize all pip install operations across workers using a shared lock file (/tmp/open-webui-pip-install.lock). Only one worker can install packages at a time, preventing race conditions.

Testing:

Tested with multiple workers (UVICORN_WORKERS > 1)
Verified FileLock prevents concurrent pip installs

Dependencies:

Added filelock==3.24.2 to backend/requirements.txt in order to establish a system agnostic lock for multiple workers
Compatible with Python 3.10+ (filelock requirement)
Gracefully falls back to direct pip call if filelock is unavailable (though this should not occur in normal deployments)

Screenshots or Videos

Multiple workers package site conflicts before changes

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/21573 **Author:** [@jmleksan](https://github.com/jmleksan) **Created:** 2/18/2026 **Status:** ❌ Closed **Base:** `dev` ← **Head:** `fix/pip-install-lock` --- ### 📝 Commits (10+) - [`fe6783c`](https://github.com/open-webui/open-webui/commit/fe6783c16699911c7be17392596d579333fb110c) Merge pull request #19030 from open-webui/dev - [`fc05e0a`](https://github.com/open-webui/open-webui/commit/fc05e0a6c5d39da60b603b4d520f800d6e36f748) Merge pull request #19405 from open-webui/dev - [`e3faec6`](https://github.com/open-webui/open-webui/commit/e3faec62c58e3a83d89aa3df539feacefa125e0c) Merge pull request #19416 from open-webui/dev - [`9899293`](https://github.com/open-webui/open-webui/commit/9899293f050ad50ae12024cbebee7e018acd851e) Merge pull request #19448 from open-webui/dev - [`140605e`](https://github.com/open-webui/open-webui/commit/140605e660b8186a7d5c79fb3be6ffb147a2f498) Merge pull request #19462 from open-webui/dev - [`6f1486f`](https://github.com/open-webui/open-webui/commit/6f1486ffd0cb288d0e21f41845361924e0d742b3) Merge pull request #19466 from open-webui/dev - [`bc599ae`](https://github.com/open-webui/open-webui/commit/bc599ae642b72da08df303c0428944d54ffecb1e) elastic - [`d95f533`](https://github.com/open-webui/open-webui/commit/d95f533214e3fe5beb5e41ec1f349940bc4c7043) Merge pull request #19729 from open-webui/dev - [`a727153`](https://github.com/open-webui/open-webui/commit/a7271532f8a38da46785afcaa7e65f9a45e7d753) 0.6.43 (#20093) - [`6adde20`](https://github.com/open-webui/open-webui/commit/6adde203cd292a9e3af9c64a2ae36b603fed096a) Merge pull request #20394 from open-webui/dev ### 📊 Changes **2 files changed** (+23 additions, -0 deletions) <details> <summary>View changed files</summary> 📝 `backend/open_webui/utils/plugin.py` (+22 -0) 📝 `backend/requirements.txt` (+1 -0) </details> ### 📄 Description  # Pull Request Checklist This is to ensure large feature PRs are discussed with the community first, before starting work on it. If the community does not want this feature or it is not relevant for Open WebUI as a project, it can be identified in the discussion before working on the feature and submitting the PR. **Before submitting, make sure you've checked the following:** - [x] **Target branch:** Verify that the pull request targets the `dev` branch. **PRs targeting `main` will be immediately closed.** - [x] **Description:** Provide a concise description of the changes made in this pull request down below. - [x] **Changelog:** Ensure a changelog entry following the format of [Keep a Changelog](https://keepachangelog.com/) is added at the bottom of the PR description. - [x] **Documentation:** Add docs in [Open WebUI Docs Repository](https://github.com/open-webui/docs). Document user-facing behavior, environment variables, public APIs/interfaces, or deployment steps. - [x] **Dependencies:** Are there any new or upgraded dependencies? If so, explain why, update the changelog/docs, and include any compatibility notes. Actually run the code/function that uses updated library to ensure it doesn't crash. - [x] **Testing:** Perform manual tests to **verify the implemented fix/feature works as intended AND does not break any other functionality**. Include reproducible steps to demonstrate the issue before the fix. Test edge cases (URL encoding, HTML entities, types). Take this as an opportunity to **make screenshots of the feature/fix and include them in the PR description**. - [x] **Agentic AI Code:** Confirm this Pull Request is **not written by any AI Agent** or has at least **gone through additional human review AND manual testing**. If any AI Agent is the co-author of this PR, it may lead to immediate closure of the PR. - [x] **Code review:** Have you performed a self-review of your code, addressing any coding standard issues and ensuring adherence to the project's coding standards? - [x] **Design & Architecture:** Prefer smart defaults over adding new settings; use local state for ephemeral UI logic. Open a Discussion for major architectural or UX changes. - [x] **Git Hygiene:** Keep PRs atomic (one logical change). Clean up commits and rebase on `dev` to ensure no unrelated commits (e.g. from `main`) are included. Push updates to the existing PR branch instead of closing and reopening. - [x] **Title Prefix:** To clearly categorize this pull request, prefix the pull request title using one of the following: - **BREAKING CHANGE**: Significant changes that may affect compatibility - **build**: Changes that affect the build system or external dependencies - **ci**: Changes to our continuous integration processes or workflows - **chore**: Refactor, cleanup, or other non-functional code changes - **docs**: Documentation update or addition - **feat**: Introduces a new feature or enhancement to the codebase - **fix**: Bug fix or error correction - **i18n**: Internationalization or localization changes - **perf**: Performance improvement - **refactor**: Code restructuring for better maintainability, readability, or scalability - **style**: Changes that do not affect the meaning of the code (white space, formatting, missing semi-colons, etc.) - **test**: Adding missing tests or correcting existing tests - **WIP**: Work in progress, a temporary label for incomplete or ongoing work # Changelog Entry ### Description - Fixes race condition in multi-worker deployments where concurrent pip package installations cause `AssertionError` when multiple workers attempt to install function/tool requirements simultaneously. Adds file-based locking to serialize pip install operations across workers. ### Added - FileLock-based synchronization for pip install operations to prevent concurrent installations across multiple workers ### Changed - Pip install operations now use a file lock (`/tmp/open-webui-pip-install.lock`) to ensure only one worker installs packages at a time ### Fixed - **Race condition causing `AssertionError`**: Multiple workers attempting concurrent pip installations now serialize using FileLock, preventing crashes in multi-worker deployments (e.g., UVICORN_WORKERS > 1) --- ### Additional Information **Problem:** In multi-worker deployments (e.g.,UVICORN_WORKERS > 1), when multiple workers start simultaneously or when functions/tools are loaded concurrently, each worker attempts to install pip packages independently. This causes `AssertionError: Multiple processes are trying to acquire the lock` because pip's internal locking mechanism detects concurrent install attempts. **Solution:** **FileLock serialization**: Added `filelock` library to serialize all pip install operations across workers using a shared lock file (`/tmp/open-webui-pip-install.lock`). Only one worker can install packages at a time, preventing race conditions. **Testing:** - Tested with multiple workers (UVICORN_WORKERS > 1) - Verified FileLock prevents concurrent pip installs **Dependencies:** - Added `filelock==3.24.2` to `backend/requirements.txt` in order to establish a system agnostic lock for multiple workers - Compatible with Python 3.10+ (filelock requirement) - Gracefully falls back to direct pip call if filelock is unavailable (though this should not occur in normal deployments) ### Screenshots or Videos - Multiple workers package site conflicts before changes <img width="1404" height="418" alt="image" src="https://github.com/user-attachments/assets/f522b7f7-5b5c-4524-9076-c3ccdf88bc6a" /> ### 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 2026-04-30 01:30:58 -05:00

GiteaMirror closed this issue

2026-04-30 01:31:00 -05:00

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Reference: github-starred/open-webui#49191