7e5abd504f
Add three DBOS SDK skills with reference documentation for building reliable, fault-tolerant applications with durable workflows. Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
53 lines
1.5 KiB
Markdown
53 lines
1.5 KiB
Markdown
---
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title: Use Workflow IDs for Idempotency
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impact: MEDIUM
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impactDescription: Prevents duplicate executions of critical operations
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tags: idempotency, workflow-id, deduplication, exactly-once
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---
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## Use Workflow IDs for Idempotency
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Set workflow IDs to make operations idempotent. A workflow with the same ID executes only once.
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**Incorrect (duplicate payments possible):**
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```python
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@app.post("/pay/{order_id}")
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def process_payment(order_id: str):
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# Multiple clicks = multiple payments!
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handle = DBOS.start_workflow(payment_workflow, order_id)
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return handle.get_result()
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```
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**Correct (idempotent with workflow ID):**
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```python
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from dbos import SetWorkflowID
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@app.post("/pay/{order_id}")
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def process_payment(order_id: str):
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# Same order_id = same workflow ID = only one execution
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with SetWorkflowID(f"payment-{order_id}"):
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handle = DBOS.start_workflow(payment_workflow, order_id)
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return handle.get_result()
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@DBOS.workflow()
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def payment_workflow(order_id: str):
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charge_customer(order_id)
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send_confirmation(order_id)
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return "success"
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```
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Access the workflow ID inside workflows:
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```python
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@DBOS.workflow()
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def my_workflow():
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current_id = DBOS.workflow_id
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DBOS.logger.info(f"Running workflow {current_id}")
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```
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Workflow IDs must be globally unique. Duplicate IDs return the existing workflow's result without re-executing.
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Reference: [Workflow IDs and Idempotency](https://docs.dbos.dev/python/tutorials/workflow-tutorial#workflow-ids-and-idempotency)
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