kgabryje opened a new pull request, #38634: URL: https://github.com/apache/superset/pull/38634
<!--- Please write the PR title following the conventions at https://www.conventionalcommits.org/en/v1.0.0/ Example: fix(dashboard): load charts correctly --> ### SUMMARY Fixes two issues in the MCP chatbot/SQL execution flow: 1. Cached query results failing with bytes/encoding errors — The result cache was storing raw pandas DataFrames (which get pickled by some cache backends into bytes). On retrieval, the code assumed thedata was always a DataFrame, causing errors when encountering bytes. This PR serializes DataFrames to a JSON-safe dict format ({"records": [...], "columns": [...]}) before caching, and adds a _deserialize_cached_data() method that gracefully handles all formats (dict, DataFrame, None, and bytes as a cache miss) — intentionally avoiding pickle deserialization to prevent code-execution attacks from a compromised cache backend. 2. MCP middleware ordering was reversed — FastMCP 2.14+ changed how middleware is chained (uses reversed(middleware)), so the first-added middleware is now outermost. The middleware list ordering in server.py was updated to reflect this: GlobalErrorHandler → Logging → SizeGuard → Caching (outermost → innermost). ### BEFORE/AFTER SCREENSHOTS OR ANIMATED GIF <!--- Skip this if not applicable --> ### TESTING INSTRUCTIONS 1. Start Superset with MCP enabled 2. Run a SQL query via the MCP chatbot that returns results 4. Run the same query again — it should hit the cache and return correctly (no bytes/encoding errors) 5. Verify DML queries (INSERT/UPDATE) that return no data also work from cache 6. Verify middleware logging shows correct nesting order (error handler outermost) ### ADDITIONAL INFORMATION <!--- Check any relevant boxes with "x" --> <!--- HINT: Include "Fixes #nnn" if you are fixing an existing issue --> - [ ] Has associated issue: - [ ] Required feature flags: - [ ] Changes UI - [ ] Includes DB Migration (follow approval process in [SIP-59](https://github.com/apache/superset/issues/13351)) - [ ] Migration is atomic, supports rollback & is backwards-compatible - [ ] Confirm DB migration upgrade and downgrade tested - [ ] Runtime estimates and downtime expectations provided - [ ] Introduces new feature or API - [ ] Removes existing feature or API -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
