60 lines
1.4 KiB
Markdown
60 lines
1.4 KiB
Markdown
---
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title: Set Workflow Timeouts
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impact: CRITICAL
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impactDescription: Prevents runaway workflows from consuming resources
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tags: timeout, cancel, deadline, limits
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---
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## Set Workflow Timeouts
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Use `SetWorkflowTimeout` to limit workflow execution time. Timed-out workflows are cancelled.
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**Incorrect (no timeout):**
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```python
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@DBOS.workflow()
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def potentially_long_workflow():
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# Could run forever!
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while not done:
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process_next()
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```
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**Correct (with timeout):**
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```python
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from dbos import SetWorkflowTimeout
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@DBOS.workflow()
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def bounded_workflow():
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while not done:
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process_next()
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# Workflow must complete within 60 seconds
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with SetWorkflowTimeout(60):
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bounded_workflow()
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# Or with start_workflow
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with SetWorkflowTimeout(60):
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handle = DBOS.start_workflow(bounded_workflow)
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```
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Timeout behavior:
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- Timeout is **start-to-completion** (doesn't count queue wait time)
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- Timeouts are **durable** (persist across restarts)
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- Cancellation happens at the **beginning of the next step**
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- **All child workflows** are also cancelled
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With queues:
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```python
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queue = Queue("example_queue")
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# Timeout starts when dequeued, not when enqueued
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with SetWorkflowTimeout(30):
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queue.enqueue(my_workflow)
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```
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Timeouts work with long durations (hours, days, weeks) since they're stored in the database.
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Reference: [Workflow Timeouts](https://docs.dbos.dev/python/tutorials/workflow-tutorial#workflow-timeouts)
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