It seems that the information provided about the Pull Request (PR) is incomplete or undefined. To create a summary for an advanced developer regarding a specific PR in the thanos-io/thanos project, I would need key details typically found in a PR description, such as:

  1. Title of the PR: What change or feature is being introduced?
  2. Description: A detailed explanation of the changes made, including the problem being addressed and the rationale behind the modifications.
  3. Key Changes: A summary of the main code changes, files modified, and any new functionality added.
  4. Impact: How these changes affect the existing codebase, any breaking changes, and the intended benefits.
  5. Testing: Information about how the changes were tested and any relevant testing framework or strategy used.
  6. Issue Reference: Any related issues or discussions that prompted this PR.

If you can provide this information, I can help generate a concise and informative summary tailored for an advanced developer.