Steps

When using DBOS workflows, we recommend annotating any function that performs complex operations or accesses external APIs or services as a step.

You can turn any Python function into a step by annotating it with the @DBOS.step decorator. The only requirement is that its inputs and outputs should be serializable (pickle-able). Here's a simple example:

@DBOS.step()
def example_step():
    return requests.get("https://example.com").text

You should make a function a step if you're using it in a DBOS workflow and it accesses an external API or service, like serving a file from AWS S3, calling an external API like Stripe, or accessing an external data store like Elasticsearch.

Making a function a step has two benefits:

If a workflow is interrupted, upon restart it automatically resumes execution from the last completed step. Therefore, making a function a step guarantees that a workflow will never re-execute it once it completes.
DBOS provides configurable automatic retries for steps to more easily handle transient errors.

Configurable Retries

You can optionally configure a step to automatically retry any exception a set number of times with exponential backoff. Retries are configurable through arguments to the step decorator:

DBOS.step(
    retries_allowed: bool = False,
    interval_seconds: float = 1.0,
    max_attempts: int = 3,
    backoff_rate: float = 2.0
)

For example, we configure this step to retry exceptions (such as if example.com is temporarily down) up to 10 times:

@DBOS.step(retries_allowed=True, max_attempts=10)
def example_step():
    return requests.get("https://example.com").text

Configurable Retries​

Configurable Retries