Refactor MCP session manager for better configurability and cleanup by edwinjosechittilappilly · Pull Request #9176 · langflow-ai/langflow

edwinjosechittilappilly · 2025-07-24T20:14:35Z

Replaces hardcoded MCP session manager constants with settings-driven values for max sessions, idle timeout, and cleanup interval. Improves session reuse and cleanup logic by introducing context-to-session mapping and reference counting for backward compatibility. Enhances session connectivity validation, error handling, and adds best-effort remote session termination for SSE clients. Updates settings to expose new MCP session manager tuning parameters.

coderabbitai · 2025-07-24T20:14:42Z

Important

Review skipped

Auto reviews are disabled on base/target branches other than the default branch.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

✨ Finishing Touches

🧪 Generate unit tests

Create PR with unit tests
Post copyable unit tests in a comment
Commit unit tests in branch mcp-backward-compatibility

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

🪧 Tips

Chat

There are 3 ways to chat with CodeRabbit:

Review comments: Directly reply to a review comment made by CodeRabbit. Example:
- I pushed a fix in commit <commit_id>, please review it.
- Explain this complex logic.
- Open a follow-up GitHub issue for this discussion.
Files and specific lines of code (under the "Files changed" tab): Tag @coderabbitai in a new review comment at the desired location with your query. Examples:
- @coderabbitai explain this code block.
- @coderabbitai modularize this function.
PR comments: Tag @coderabbitai in a new PR comment to ask questions about the PR branch. For the best results, please provide a very specific query, as very limited context is provided in this mode. Examples:
- @coderabbitai gather interesting stats about this repository and render them as a table. Additionally, render a pie chart showing the language distribution in the codebase.
- @coderabbitai read src/utils.ts and explain its main purpose.
- @coderabbitai read the files in the src/scheduler package and generate a class diagram using mermaid and a README in the markdown format.
- @coderabbitai help me debug CodeRabbit configuration file.

Support

Need help? Create a ticket on our support page for assistance with any issues or questions.

Note: Be mindful of the bot's finite context window. It's strongly recommended to break down tasks such as reading entire modules into smaller chunks. For a focused discussion, use review comments to chat about specific files and their changes, instead of using the PR comments.

CodeRabbit Commands (Invoked using PR comments)

@coderabbitai pause to pause the reviews on a PR.
@coderabbitai resume to resume the paused reviews.
@coderabbitai review to trigger an incremental review. This is useful when automatic reviews are disabled for the repository.
@coderabbitai full review to do a full review from scratch and review all the files again.
@coderabbitai summary to regenerate the summary of the PR.
@coderabbitai generate docstrings to generate docstrings for this PR.
@coderabbitai generate sequence diagram to generate a sequence diagram of the changes in this PR.
@coderabbitai generate unit tests to generate unit tests for this PR.
@coderabbitai resolve resolve all the CodeRabbit review comments.
@coderabbitai configuration to show the current CodeRabbit configuration for the repository.
@coderabbitai help to get help.

Other keywords and placeholders

Add @coderabbitai ignore anywhere in the PR description to prevent this PR from being reviewed.
Add @coderabbitai summary to generate the high-level summary at a specific location in the PR description.
Add @coderabbitai anywhere in the PR title to generate the title automatically.

Documentation and Community

Visit our Documentation for detailed information on how to use CodeRabbit.
Join our Discord Community to get help, request features, and share feedback.
Follow us on X/Twitter for updates and announcements.

… tests (#9077) * update MCP Tests * [autofix.ci] apply automated fixes * Update util.py * [autofix.ci] apply automated fixes * Refactor MCP session manager for better configurability and cleanup (#9176) * Add log rotation and header validation features Introduces support for log rotation via the LANGFLOW_LOG_ROTATION environment variable and CLI/config options, with documentation updates. Adds header validation and sanitization for MCP connections, ensuring RFC 7230 compliance and security. Frontend and backend now support passing custom headers for MCP servers. Includes extensive new and updated unit tests for header handling, MCP utilities, and log rotation. * Add unit tests for MCP utilities and update disconnect logic Added comprehensive unit tests for MCP utility functions, session management, header validation, and client classes in test_mcp_util.py. Updated MCPStdioClient and MCPSseClient disconnect methods for clearer session cleanup logic. Refactored test_mcp_component.py to remove redundant and duplicated tests, consolidating coverage in the new test suite. * [autofix.ci] apply automated fixes * Update test_mcp_memory_leak.py * Update util.py --------- Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com> Co-authored-by: Gabriel Luiz Freitas Almeida <gabriel@langflow.org>

* update MCP Tests * [autofix.ci] apply automated fixes * Update util.py * [autofix.ci] apply automated fixes * Refactor MCP session manager for better configurability and cleanup (#9176) * Add log rotation and header validation features Introduces support for log rotation via the LANGFLOW_LOG_ROTATION environment variable and CLI/config options, with documentation updates. Adds header validation and sanitization for MCP connections, ensuring RFC 7230 compliance and security. Frontend and backend now support passing custom headers for MCP servers. Includes extensive new and updated unit tests for header handling, MCP utilities, and log rotation. * Add unit tests for MCP utilities and update disconnect logic Added comprehensive unit tests for MCP utility functions, session management, header validation, and client classes in test_mcp_util.py. Updated MCPStdioClient and MCPSseClient disconnect methods for clearer session cleanup logic. Refactored test_mcp_component.py to remove redundant and duplicated tests, consolidating coverage in the new test suite. * [autofix.ci] apply automated fixes * Update test_mcp_memory_leak.py * Update util.py * Improve session and process cleanup in MCP Added explicit session closing and a short delay to allow subprocess transports to clean up, reducing warnings and potential memory leaks. Test code now waits longer after cleanup and increases process termination timeout to ensure all child processes are properly terminated. * Improve session and process cleanup logic Enhanced MCPSessionManager to handle both async and sync session closing methods, using inspection to determine awaitability. Updated memory leak test to more robustly wait for and clean up child processes, logging process states and handling termination more gracefully. --------- Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com> Co-authored-by: Gabriel Luiz Freitas Almeida <gabriel@langflow.org>

… tests (#9077) * update MCP Tests * [autofix.ci] apply automated fixes * Update util.py * [autofix.ci] apply automated fixes * Refactor MCP session manager for better configurability and cleanup (#9176) * Add log rotation and header validation features Introduces support for log rotation via the LANGFLOW_LOG_ROTATION environment variable and CLI/config options, with documentation updates. Adds header validation and sanitization for MCP connections, ensuring RFC 7230 compliance and security. Frontend and backend now support passing custom headers for MCP servers. Includes extensive new and updated unit tests for header handling, MCP utilities, and log rotation. * Add unit tests for MCP utilities and update disconnect logic Added comprehensive unit tests for MCP utility functions, session management, header validation, and client classes in test_mcp_util.py. Updated MCPStdioClient and MCPSseClient disconnect methods for clearer session cleanup logic. Refactored test_mcp_component.py to remove redundant and duplicated tests, consolidating coverage in the new test suite. * [autofix.ci] apply automated fixes * Update test_mcp_memory_leak.py * Update util.py --------- Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com> Co-authored-by: Gabriel Luiz Freitas Almeida <gabriel@langflow.org>

* update MCP Tests * [autofix.ci] apply automated fixes * Update util.py * [autofix.ci] apply automated fixes * Refactor MCP session manager for better configurability and cleanup (#9176) * Add log rotation and header validation features Introduces support for log rotation via the LANGFLOW_LOG_ROTATION environment variable and CLI/config options, with documentation updates. Adds header validation and sanitization for MCP connections, ensuring RFC 7230 compliance and security. Frontend and backend now support passing custom headers for MCP servers. Includes extensive new and updated unit tests for header handling, MCP utilities, and log rotation. * Add unit tests for MCP utilities and update disconnect logic Added comprehensive unit tests for MCP utility functions, session management, header validation, and client classes in test_mcp_util.py. Updated MCPStdioClient and MCPSseClient disconnect methods for clearer session cleanup logic. Refactored test_mcp_component.py to remove redundant and duplicated tests, consolidating coverage in the new test suite. * [autofix.ci] apply automated fixes * Update test_mcp_memory_leak.py * Update util.py * Improve session and process cleanup in MCP Added explicit session closing and a short delay to allow subprocess transports to clean up, reducing warnings and potential memory leaks. Test code now waits longer after cleanup and increases process termination timeout to ensure all child processes are properly terminated. * Improve session and process cleanup logic Enhanced MCPSessionManager to handle both async and sync session closing methods, using inspection to determine awaitability. Updated memory leak test to more robustly wait for and clean up child processes, logging process states and handling termination more gracefully. --------- Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com> Co-authored-by: Gabriel Luiz Freitas Almeida <gabriel@langflow.org>

… tests (#9077) * update MCP Tests * [autofix.ci] apply automated fixes * Update util.py * [autofix.ci] apply automated fixes * Refactor MCP session manager for better configurability and cleanup (#9176) * Add log rotation and header validation features Introduces support for log rotation via the LANGFLOW_LOG_ROTATION environment variable and CLI/config options, with documentation updates. Adds header validation and sanitization for MCP connections, ensuring RFC 7230 compliance and security. Frontend and backend now support passing custom headers for MCP servers. Includes extensive new and updated unit tests for header handling, MCP utilities, and log rotation. * Add unit tests for MCP utilities and update disconnect logic Added comprehensive unit tests for MCP utility functions, session management, header validation, and client classes in test_mcp_util.py. Updated MCPStdioClient and MCPSseClient disconnect methods for clearer session cleanup logic. Refactored test_mcp_component.py to remove redundant and duplicated tests, consolidating coverage in the new test suite. * [autofix.ci] apply automated fixes * Update test_mcp_memory_leak.py * Update util.py --------- Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com> Co-authored-by: Gabriel Luiz Freitas Almeida <gabriel@langflow.org>

* update MCP Tests * [autofix.ci] apply automated fixes * Update util.py * [autofix.ci] apply automated fixes * Refactor MCP session manager for better configurability and cleanup (#9176) * Add log rotation and header validation features Introduces support for log rotation via the LANGFLOW_LOG_ROTATION environment variable and CLI/config options, with documentation updates. Adds header validation and sanitization for MCP connections, ensuring RFC 7230 compliance and security. Frontend and backend now support passing custom headers for MCP servers. Includes extensive new and updated unit tests for header handling, MCP utilities, and log rotation. * Add unit tests for MCP utilities and update disconnect logic Added comprehensive unit tests for MCP utility functions, session management, header validation, and client classes in test_mcp_util.py. Updated MCPStdioClient and MCPSseClient disconnect methods for clearer session cleanup logic. Refactored test_mcp_component.py to remove redundant and duplicated tests, consolidating coverage in the new test suite. * [autofix.ci] apply automated fixes * Update test_mcp_memory_leak.py * Update util.py * Improve session and process cleanup in MCP Added explicit session closing and a short delay to allow subprocess transports to clean up, reducing warnings and potential memory leaks. Test code now waits longer after cleanup and increases process termination timeout to ensure all child processes are properly terminated. * Improve session and process cleanup logic Enhanced MCPSessionManager to handle both async and sync session closing methods, using inspection to determine awaitability. Updated memory leak test to more robustly wait for and clean up child processes, logging process states and handling termination more gracefully. --------- Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com> Co-authored-by: Gabriel Luiz Freitas Almeida <gabriel@langflow.org>

… tests (#9077) * update MCP Tests * [autofix.ci] apply automated fixes * Update util.py * [autofix.ci] apply automated fixes * Refactor MCP session manager for better configurability and cleanup (#9176) * Add log rotation and header validation features Introduces support for log rotation via the LANGFLOW_LOG_ROTATION environment variable and CLI/config options, with documentation updates. Adds header validation and sanitization for MCP connections, ensuring RFC 7230 compliance and security. Frontend and backend now support passing custom headers for MCP servers. Includes extensive new and updated unit tests for header handling, MCP utilities, and log rotation. * Add unit tests for MCP utilities and update disconnect logic Added comprehensive unit tests for MCP utility functions, session management, header validation, and client classes in test_mcp_util.py. Updated MCPStdioClient and MCPSseClient disconnect methods for clearer session cleanup logic. Refactored test_mcp_component.py to remove redundant and duplicated tests, consolidating coverage in the new test suite. * [autofix.ci] apply automated fixes * Update test_mcp_memory_leak.py * Update util.py --------- Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com> Co-authored-by: Gabriel Luiz Freitas Almeida <gabriel@langflow.org>

* update MCP Tests * [autofix.ci] apply automated fixes * Update util.py * [autofix.ci] apply automated fixes * Refactor MCP session manager for better configurability and cleanup (#9176) * Add log rotation and header validation features Introduces support for log rotation via the LANGFLOW_LOG_ROTATION environment variable and CLI/config options, with documentation updates. Adds header validation and sanitization for MCP connections, ensuring RFC 7230 compliance and security. Frontend and backend now support passing custom headers for MCP servers. Includes extensive new and updated unit tests for header handling, MCP utilities, and log rotation. * Add unit tests for MCP utilities and update disconnect logic Added comprehensive unit tests for MCP utility functions, session management, header validation, and client classes in test_mcp_util.py. Updated MCPStdioClient and MCPSseClient disconnect methods for clearer session cleanup logic. Refactored test_mcp_component.py to remove redundant and duplicated tests, consolidating coverage in the new test suite. * [autofix.ci] apply automated fixes * Update test_mcp_memory_leak.py * Update util.py * Improve session and process cleanup in MCP Added explicit session closing and a short delay to allow subprocess transports to clean up, reducing warnings and potential memory leaks. Test code now waits longer after cleanup and increases process termination timeout to ensure all child processes are properly terminated. * Improve session and process cleanup logic Enhanced MCPSessionManager to handle both async and sync session closing methods, using inspection to determine awaitability. Updated memory leak test to more robustly wait for and clean up child processes, logging process states and handling termination more gracefully. --------- Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com> Co-authored-by: Gabriel Luiz Freitas Almeida <gabriel@langflow.org>

edwinjosechittilappilly merged commit 6d0186c into mcp_memory_leak Jul 24, 2025
4 of 6 checks passed

edwinjosechittilappilly deleted the mcp-backward-compatibility branch July 24, 2025 20:14

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Refactor MCP session manager for better configurability and cleanup#9176

Refactor MCP session manager for better configurability and cleanup#9176
edwinjosechittilappilly merged 1 commit into
mcp_memory_leakfrom
mcp-backward-compatibility

edwinjosechittilappilly commented Jul 24, 2025

Uh oh!

coderabbitai Bot commented Jul 24, 2025

Review skipped

Chat

Support

CodeRabbit Commands (Invoked using PR comments)

Other keywords and placeholders

Documentation and Community

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

1 participant

Conversation

edwinjosechittilappilly commented Jul 24, 2025

Uh oh!

coderabbitai Bot commented Jul 24, 2025

Review skipped

Chat

Support

CodeRabbit Commands (Invoked using PR comments)

Other keywords and placeholders

Documentation and Community

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

1 participant