Airflow Xcom Exclusive 2021 -

In Apache Airflow, XCom (short for "cross-communication") is the primary mechanism for tasks to share small pieces of data within a DAG run. Unlike global Variables, which are designed for static configuration, XComs are tied to specific task instances and the lifecycle of a single execution. Core Functionality: Push & Pull

Part 7: Common Pitfalls and How to Avoid Them

Pitfall 1: Over-Exclusivity

Problem: You push a result, but no downstream task is allowed to pull it.
Solution: Define the exclusive mapping at DAG level, and review with airflow dags show-xcom --exclusive-violations. airflow xcom exclusive

dag = DAG( 'xcom_example', default_args=default_args, schedule_interval=timedelta(days=1), )

Redis SETNX or Redlock for distributed lock.
Database row advisory locks (Postgres pg_advisory_lock) if you control DB.