What causes Task Graph Cycle Detected?

Task B lists Task A as a predecessor while Task A also lists Task B (direct cycle). Multi-task DAG where an indirect chain creates a loop: A → B → C → A. Copy-paste error when building a large task graph that accidentally creates a back-edge. Dynamic task graph generation producing incorrect predecessor assignments

How do I fix Task Graph Cycle Detected?

Map out the full task dependency graph and identify the cycle. Remove the task definition creating the back-edge: `ALTER TASK REMOVE AFTER `. Rebuild the graph as a true DAG (no cycles) — Snowflake only supports directed acyclic task graphs. Use `SHOW TASKS IN SCHEMA ` and the `PREDECESSORS` column to inspect the current graph. Query `SNOWFLAKE.ACCOUNT_USAGE.TASK_HISTORY` to verify which tasks are running and in what order

High severitydata pipeline

Power BI Refresh Error:
Task Graph Cycle Detected

What does this error mean?

A Snowflake Task DAG definition creates a cycle — a task directly or indirectly depends on itself. Snowflake rejects cyclic task graphs at creation or resume time.

Common causes

1Task B lists Task A as a predecessor while Task A also lists Task B (direct cycle)
2Multi-task DAG where an indirect chain creates a loop: A → B → C → A
3Copy-paste error when building a large task graph that accidentally creates a back-edge
4Dynamic task graph generation producing incorrect predecessor assignments

How to fix it

1Map out the full task dependency graph and identify the cycle
2Remove the task definition creating the back-edge: `ALTER TASK <task> REMOVE AFTER <predecessor>`
3Rebuild the graph as a true DAG (no cycles) — Snowflake only supports directed acyclic task graphs
4Use `SHOW TASKS IN SCHEMA <schema>` and the `PREDECESSORS` column to inspect the current graph
5Query `SNOWFLAKE.ACCOUNT_USAGE.TASK_HISTORY` to verify which tasks are running and in what order

Frequently asked questions

Does Snowflake support any form of looping in task graphs?

No — Snowflake task graphs must be directed acyclic graphs (DAGs). For iterative processing patterns, use a Stored Procedure called by a single task instead.