Reviewed by Aditya Kumar ¡ Last reviewed 2026-03-24
**XCom**: Cross-communicationâtasks pass small data (e.g., file path, ID). Push via return value or xcom_push(); pull via xcom_pull(). Stored in metadata DB. **Limitation**: Not for large dataâmetadata DB is not a store. Typical limit ~1 KB per value (configurable but not...
XCom: Cross-communicationâtasks pass small data (e.g., file path, ID). Push via return value or xcom_push(); pull via xcom_pull(). Stored in metadata DB. Limitation: Not for large dataâmetadata DB is not a store. Typical limit ~1 KB per value (configurable but not recommended to increase). Use: Pass S3 paths, query IDs, status codes. Best practice: Pass references, not payloads. For large data, use external storage (S3, DB) and pass reference. Scalability: Many XComs add DB load; keep minimal.
Pro-Move: 'We pass only S3 paths in XComâ"s3://bucket/key"; tasks read/write to S3; XCom stays under 100 bytes.' Red Flag: Pushing DataFrames or large JSON to XComâwill bloat metadata DB.
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