fix: health check for mcp server

[phact]

This pull request simplifies session management in the MCP utility module by removing redundant methods and improving the session health check logic. It also enhances logging to provide better insights into session states.

Improvements to session management:

• Refactored session health check logic:

  • Simplified the health check process in get_session by breaking it into smaller checks and adding detailed debug logs to explain why cleanup is triggered. This improves code readability and debugging capabilities.

• Removed redundant session creation and cleanup methods:

  • Eliminated _create_fresh_session, _cleanup_session, and disconnect methods, consolidating session management responsibilities into the session manager. This reduces duplication and streamlines the codebase.

Summary by CodeRabbit

• Bug Fixes

  • Improved reliability of session health checks, reducing the likelihood of unexpected session reuse or cleanup issues.
  • Enhanced logging for better traceability of session status and errors.

• Refactor

  • Streamlined session management by consolidating session lifecycle responsibilities, resulting in a cleaner and more maintainable backend.

[coderabbitai]

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Walkthrough

The session health check logic in MCPSessionManager.get_session was simplified to rely only on the background task's status, with enhanced debug logging for session reuse and cleanup. Exception handling was improved for dead sessions. Session lifecycle management methods were removed from MCPStdioClient, centralizing this responsibility in the manager.

Changes

File(s)	Change Summary
src/backend/base/langflow/base/mcp/util.py	Simplified session health check logic, added debug logging, improved exception handling, and removed _create_fresh_session, _cleanup_session, and disconnect methods from MCPStdioClient.

Sequence Diagram(s)

sequenceDiagram
    participant Client as MCPStdioClient
    participant Manager as MCPSessionManager
    participant Task as BackgroundTask

    Client->>Manager: get_session()
    Manager->>Task: Check if task.done()
    alt Task is running
        Manager-->>Client: Return existing session
    else Task is done
        Manager->>Manager: Cleanup session
        Manager-->>Client: Create and return new session
    end

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[lucaseduoli]

LGTM!