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prefect.runner.runner

Runners are responsible for managing the execution of all deployments.

When creating a deployment using either flow.serve or the serve utility, they also will poll for scheduled runs.

Example:

import time
from prefect import flow, serve


@flow
def slow_flow(sleep: int = 60):
    "Sleepy flow - sleeps the provided amount of time (in seconds)."
    time.sleep(sleep)


@flow
def fast_flow():
    "Fastest flow this side of the Mississippi."
    return


if __name__ == "__main__":
    slow_deploy = slow_flow.to_deployment(name="sleeper", interval=45)
    fast_deploy = fast_flow.to_deployment(name="fast")

    # serve generates a Runner instance
    serve(slow_deploy, fast_deploy)

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Classes

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ProcessMapEntry

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Runner

Methods:

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handle_sigterm

handle_sigterm(self, *args: Any, **kwargs: Any) -> None

Gracefully shuts down the runner when a SIGTERM is received.

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execute_in_background

execute_in_background(self, func: Callable[..., Any], *args: Any, **kwargs: Any) -> 'concurrent.futures.Future[Any]'

Executes a function in the background.

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reschedule_current_flow_runs

reschedule_current_flow_runs(self) -> None

Reschedules all flow runs that are currently running.

This should only be called when the runner is shutting down because it kill all child processes and short-circuit the crash detection logic.

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has_slots_available

has_slots_available(self) -> bool

Determine if the flow run limit has been reached.

Returns:

• • bool: True if the limit has not been reached, False otherwise.