@Marvin, can I gracefully terminate a deployment’s flow run if the deployment still has a previously running flow run?

The search results did not yield direct information on gracefully terminating a deployment's flow run if a previous run is still active. However, you can conditionally handle flow runs using conditional checks and the

pause_flow_run

function. You can pause and resume flow runs based on specific conditions. For more comprehensive guidance, you'll need to check Prefect's latest documentation or Prefect GitHub Issues for similar user queries and solutions. 🔗 Resources: - Prefect Deployments - Pausing Flow Runs Feel free to explore these links for more detailed strategies tailored to your requirements.

@Marvin how can I retrieve a list of a deployment’s runs that are still running?

To retrieve a list of a deployment's runs that are still running, you can use the Prefect Client API to filter and list the flow runs based on their state. Here is an example of how to do this in Python:

python
from prefect.client import get_client
from prefect.orion.schemas.filters import FlowRunFilter, FlowRunFilterStateName

async def list_running_flow_runs(deployment_id: str):
    async with get_client() as client:
        flow_run_filter = FlowRunFilter(
            deployment_id={"any_":[deployment_id]},
            state={"type": ["Running"]}
        )
        
        flow_runs = await client.read_flow_runs(flow_run_filter)
        return flow_runs

# Example usage
if __name__ == "__main__":
    import asyncio
    deployment_id = "your_deployment_id_here"
    flow_runs = asyncio.run(list_running_flow_runs(deployment_id))
    for run in flow_runs:
        print(run)

In this example, we: 1. Connect to the Prefect client. 2. Define a filter for flow runs that match the specified deployment ID and are in the "Running" state. 3. Use the

client.read_flow_runs

method to retrieve a list of such flow runs. You can modify the

deployment_id

with the ID of your specific deployment. 🔗 Resources: - Using the Prefect Client - Flow Run Filters This will give you an up-to-date list of all active runs for a given deployment.

@Marvin can you show a sample of the client method read_flow_runs() with a FlowRunFilter that filters on a deployment_id and a list of flow run states?

It looks like the provided code example isn't directly related to the

read_flow_runs

method with

FlowRunFilter

. I will create a custom example for you. Here's a sample code that demonstrates how to use the

read_flow_runs

method with a

FlowRunFilter

to filter based on

deployment_id

and a list of flow run states:

python
from prefect.client import get_client
from prefect.orion.schemas.filters import FlowRunFilter

async def list_filtered_flow_runs(deployment_id: str, states: list):
    async with get_client() as client:
        flow_run_filter = FlowRunFilter(
            deployment_id={"any_": [deployment_id]},
            state={"type": states}
        )
        
        flow_runs = await client.read_flow_runs(flow_run_filter)
        return flow_runs

# Example usage
if __name__ == "__main__":
    import asyncio
    deployment_id = "your_deployment_id_here"
    states = ["Running", "Scheduled"]  # List of states you want to filter on
    flow_runs = asyncio.run(list_filtered_flow_runs(deployment_id, states))
    for run in flow_runs:
        print(run)

In this code: 1. We connect to the Prefect client using

get_client()

. 2. Create a

FlowRunFilter

with the

deployment_id

and a list of desired states. 3. Use

client.read_flow_runs()

to fetch the flow runs that match the filter criteria. Make sure to replace

"your_deployment_id_here"

with the actual deployment ID and modify the

states

list as needed. This should help you retrieve and filter the flow runs based on your deployment and specified states.

@Marvin I get this error when I use the above:

pydantic.error_wrappers.ValidationError: 1 validation error for FlowRunFilter
state -> type
  value is not a valid dict (type=type_error.dict)

What is the correct way to define the state filter?

The error indicates that the

state

filter requires a dictionary format. Let's correct the implementation: Here's the adjusted example:

python
from prefect.client import get_client
from prefect.orion.schemas.filters import FlowRunFilter, FlowRunFilterState, FlowRunFilterStateName

async def list_filtered_flow_runs(deployment_id: str, states: list):
    async with get_client() as client:
        flow_run_filter = FlowRunFilter(
            deployment_id={"any_": [deployment_id]},
            state=FlowRunFilterState(
                name=FlowRunFilterStateName(any_=states)
            )
        )
        
        flow_runs = await client.read_flow_runs(flow_run_filter)
        return flow_runs

# Example usage
if __name__ == "__main__":
    import asyncio
    deployment_id = "your_deployment_id_here"
    states = ["Running", "Scheduled"]  # List of states you want to filter on
    flow_runs = asyncio.run(list_filtered_flow_runs(deployment_id, states))
    for run in flow_runs:
        print(run)

In this corrected implementation: - We use

FlowRunFilterState

to define the state filter. - Within

FlowRunFilterState

,

FlowRunFilterStateName

is used to specify the list of states. This should resolve the validation error and provide the filtered list of flow runs.

@Marvin How can I dynamically get the deployment Id for the current deployment run?

To dynamically get the deployment ID for the current deployment run, you can utilize the Prefect runtime context. Here’s a code snippet demonstrating how to fetch the deployment ID from the runtime context:

python
from prefect import flow
from prefect.context import FlowRunContext

@flow
def my_flow():
    # Access the runtime context
    context = FlowRunContext.get()
    
    if context:
        deployment_id = context.flow_run.deployment_id
        print(f"Deployment ID: {deployment_id}")
    else:
        print("No context available")

if __name__ == "__main__":
    my_flow()

In this example: 1. Use

FlowRunContext.get()

to fetch the current runtime context. 2. Access the

deployment_id

from the

context.flow_run

. This code will print the deployment ID for the current deployment run if it exists. 🔗 Resource: - Runtime Context This approach will give you the deployment ID dynamically during the execution of your flow.