[Bugfix][Router]: reconfigure callbacks with dynamic config

[antoineauger]

Follow-up of #621, I noticed that the callbacks config option was not automatically reconfigured at runtime with Dynamic Config.

I tested this locally by updating the callbacks config option while vllm-router was running.

🛠️ with ❤️ by Siemens

---

• Make sure the code changes pass the pre-commit checks.
• Sign-off your commit by using -s when doing git commit
• Try to classify PRs for easy understanding of the type of changes, such as [Bugfix], [Feat], and [CI].

Detailed Checklist (Click to Expand)

Thank you for your contribution to production-stack! Before submitting the pull request, please ensure the PR meets the following criteria. This helps us maintain the code quality and improve the efficiency of the review process.

PR Title and Classification

Please try to classify PRs for easy understanding of the type of changes. The PR title is prefixed appropriately to indicate the type of change. Please use one of the following:

• [Bugfix] for bug fixes.
• [CI/Build] for build or continuous integration improvements.
• [Doc] for documentation fixes and improvements.
• [Feat] for new features in the cluster (e.g., autoscaling, disaggregated prefill, etc.).
• [Router] for changes to the vllm_router (e.g., routing algorithm, router observability, etc.).
• [Misc] for PRs that do not fit the above categories. Please use this sparingly.

Note: If the PR spans more than one category, please include all relevant prefixes.

Code Quality

The PR need to meet the following code quality standards:

• Pass all linter checks. Please use pre-commit to format your code. See README.md for installation.
• The code need to be well-documented to ensure future contributors can easily understand the code.
• Please include sufficient tests to ensure the change is stay correct and robust. This includes both unit tests and integration tests.

DCO and Signed-off-by

When contributing changes to this project, you must agree to the DCO. Commits must include a Signed-off-by: header which certifies agreement with the terms of the DCO.

Using -s with git commit will automatically add this header.

What to Expect for the Reviews

We aim to address all PRs in a timely manner. If no one reviews your PR within 5 days, please @-mention one of YuhanLiu11
, Shaoting-Feng or ApostaC.

[gemini-code-assist]

Summary of Changes

Hello @antoineauger, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request addresses an issue where the callbacks configuration option in vllm-router was not being reconfigured automatically at runtime when using Dynamic Config. It introduces the necessary logic to allow dynamic updates to callback settings, ensuring that changes to the callbacks configuration are applied without requiring a service restart.

Highlights

• Callback Configuration Refactor: The function responsible for initializing custom callbacks has been renamed from initialize_custom_callbacks to configure_custom_callbacks to better reflect its role in both initial setup and dynamic reconfiguration.
• Dynamic Callback Reconfiguration: A new method, reconfigure_callbacks, has been added to the DynamicConfigManager to handle the dynamic updating of callback settings. This method is integrated into the reconfigure_all process.
• Robust Callback Existence Check: The check for the existence of callbacks in the application state has been updated from hasattr to getattr to provide a more direct and potentially safer way to access the callbacks attribute.

Using Gemini Code Assist

The full guide for Gemini Code Assist can be found on our documentation page, here are some quick tips.

Invoking Gemini

You can request assistance from Gemini at any point in your pull request via creating an issue comment (i.e. comment on the pull request page) using either /gemini <command> or @gemini-code-assist <command>. Below is a summary of the supported commands.

Feature	Command	Description
Code Review	/gemini review	Performs a code review for the current pull request in its current state.
Pull Request Summary	/gemini summary	Provides a summary of the current pull request in its current state.
Comment	@gemini-code-assist	Responds in comments when explicitly tagged, both in issue comments and review comments.
Help	/gemini help	Displays a list of available commands.

Customization

To customize Gemini Code Assist for GitHub experience, repository maintainers can create a configuration file and/or provide a custom code review style guide (such as PEP-8 for Python) by creating and adding files to a .gemini/ folder in the base of the repository. Detailed instructions can be found here.

Limitations & Feedback

Gemini Code Assist may make mistakes. Please leave feedback on any instances where its feedback is incorrect or counter productive. You can react with 👍 and 👎 on @gemini-code-assist comments. If you're interested in giving your feedback about your experience with Gemini Code Assist for Github and other Google products, sign up here.

You can also get AI-powered code generation, chat, as well as code reviews directly in the IDE at no cost with the Gemini Code Assist IDE Extension.

Footnotes

1. Review the Privacy Notices, Generative AI Prohibited Use Policy, Terms of Service, and learn how to configure Gemini Code Assist in GitHub here. Gemini can make mistakes, so double check it and use code with caution. ↩

[gemini-code-assist]

Code Review

This pull request successfully adds support for dynamic reconfiguration of callbacks, which enhances runtime flexibility. The renaming of initialize_custom_callbacks to configure_custom_callbacks is a good clarification of its role. The switch from hasattr to getattr for checking callbacks is a step in the right direction, but as implemented, it could lead to an AttributeError. I've provided critical suggestions to make these checks more robust and prevent potential runtime errors. With these changes, the feature will be solid.

[antoineauger]

/cc @YuhanLiu11 @zerofishnoodles

[zerofishnoodles]

@antoineauger It seems like the check failed, I didn't see the problem tho, Can you try to fix it or just push something to trigger the CI again since for some unknown reason we can't rerun the docs job.

[antoineauger]

@zerofishnoodles I just pushed again and this time all checks passed 🎉

[zerofishnoodles]

LGTM