<@U06RKAMK0UC> how do you define task dependency f...
# ask-aib
brief-family-9488
08/21/2025, 4:31 PM@ancient-wolf-19325 how do you define task dependency for task a -> task b -> task c , task d when there is no data dependency
j
jolly-florist-66728
08/21/2025, 4:31 PMReasoning Complete! 🤖 🔍 Searched knowledge base: I want to look up the best way to define task dependencies in a workflow when tasks need to run in a certain order, but they don't pass data between each other. This will help me give you a clear answer on how to set up these dependencies.
• Searching over 10 data sources from the following: File, Github File, Github Issue, Web
• Found 65 documents that could be relevant from the following data sources: Github File, Github Issue, Github Pull Request, Web Content.
• Filtered down to the top 30 most relevant documents.
✍️ Generated answer: I have found clear guidance on how to define task dependencies in Flyte when there is no data dependency. You can use the >> operator or runs_before to enforce execution order between tasks.
jolly-florist-66728
08/21/2025, 4:32 PMYou can define task dependencies in Flyte without passing data by using the >> (right shift) operator. For example, in a workflow, you can write: task_a() >> task_b() >> [task_c(), task_d()], which ensures task_a runs before task_b, and task_b runs before both task_c and task_d, even if there is no data passed between them. This chaining only establishes execution order, not data flow. According to the documentation, this is the recommended way to specify dependencies without data transfer between tasks or subworkflows.
Would you like more detail or a code example?
Sources:
- Flyte Fundamentals: tasks, workflows and launch plans 👍 0 button 👎 0 button 💡 Hint: Mention @runllm in the thread for followups.
b
brief-family-9488
08/21/2025, 4:36 PM@ancient-wolf-19325 Using task_a() >> task_b() >> [task_c(), task_d()] throws AttributeError: 'list' object has no attribute 'ref' exception
j
jolly-florist-66728
08/21/2025, 4:36 PMReasoning Complete! 🤖 🔍 Searched knowledge base: I want to look up why using the >> operator with a list of tasks in Flyte causes this error, and find the correct way to define these dependencies without running into this problem.
• Searching over 10 data sources from the following: File, Github File, Github Issue, Web
• Found 58 documents that could be relevant from the following data sources: Github File, Github Issue, Web Content.
• Filtered down to the top 30 most relevant documents.
✍️ Generated answer: I have found that the error occurs because the >> operator in Flyte does not support chaining to a list of tasks. You need to specify each dependency individually instead of using a list.
jolly-florist-66728
08/21/2025, 4:37 PMIt could be possible that chaining with >> only works between individual Flyte entities (tasks, subworkflows, or launch plans), not lists. Chaining like task_a() >> task_b() >> [task_c(), task_d()] is not supported and will raise an AttributeError, as lists do not have the required .ref attribute. Instead, you should chain each downstream task individually: task_b() >> task_c() and task_b() >> task_d() in separate statements. This is mentioned in the Flyte documentation and related GitHub issues.
Would you like a code example or more detail?
Sources:
- https://github.com/flyteorg/flytekit/blob/master/tests/flytekit/unit/core/test_node_creation.py
- https://github.com/flyteorg/flyte/blob/master/docs/user_guide/advanced_composition/chaining_flyte_entities.md
Note: I wasn’t able to find highly relevant data sources, but above are a few potentially relevant links. 👍 0 button 👎 0 button 💡 Hint: Mention @runllm in the thread for followups.
7 Views