Airflow Xcom Exclusive Extra Quality May 2026

Airflow XCom and Exclusive Access: A Comprehensive Guide

Pitfall 2: Mixing Backends

Problem: Some tasks use the default DB XCom, others use Redis – causing inconsistency.
Solution: Set xcom_backend globally in airflow.cfg and never override at task level unless temporary for migration.

4.3 XCom backend with row-level locking (PostgreSQL backend)

If using SqlXComBackend with PostgreSQL, you can use SELECT ... FOR UPDATE to lock an XCom row during push/pull, but Airflow does not do this automatically. airflow xcom exclusive

4.2 Unique keys per task

def task_a(**context):
    context['ti'].xcom_push(key=f"result_context['ti'].task_id", value=100)