Shaoyi Zhang
07/03/2024, 6:14 PMMarvin
07/03/2024, 6:15 PMpython
from prefect import flow, get_run_logger
from prefect.runtime.flows import FlowRunContext
from prefect.blocks.system import Download
@flow(name="My Flow")
def my_flow():
logger = get_run_logger()
# Define a unique lock name for the deployment
lock_name = f"{FlowRunContext.get().deployment_name}-lock"
with Download.block(f"{lock_name}", "/tmp/lockfile.lock") as lock:
if not lock.acquire(timeout=1):
<http://logger.info|logger.info>("Another instance is running, skipping this run.")
return
# Your flow logic here
<http://logger.info|logger.info>("Running the flow logic")
if __name__ == "__main__":
my_flow()
In this snippet:
- The Download.block
is used to create a lockfile as a hacky way to manage concurrency.
- It attempts to acquire the lock; if the lock is already held (meaning another run is in progress), it skips execution.
- If the lock is acquired, it proceeds with the flow logic.
This is a basic example to demonstrate the idea. Depending on your use case, you might want to implement a more robust locking mechanism.
For more detailed information and examples, you can refer to Prefect's documentation or explore community discussions on GitHub.Bring your towel and join one of the fastest growing data communities. Welcome to our second-generation open source orchestration platform, a completely rethought approach to dataflow automation.
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