David Martin Calalang
07/03/2025, 2:23 PMNate
07/03/2025, 2:26 PMthe scheduler/everything in dask automatically resorts to using a local cluster if it fails to connect to ECSI seem to remember that you might have posted this somewhere else. Can you show/link the code that you're using to configure your task runner?
David Martin Calalang
07/03/2025, 2:36 PMdef fargate_cluster(
n_workers=4,
scheduler_task_definition_arn: str = {task_definition},
execution_role_arn: str = {execution_role},
scheduler_timeout: str = "15 minutes",
security_groups: list[str] = {security_groups]
):
return FargateCluster(
n_workers=n_workers,
scheduler_task_definition_arn=scheduler_task_definition_arn,
execution_role_arn=execution_role_arn,
scheduler_timeout=scheduler_timeout,
security_groups=security_groups,
)
@flow(task_runner=DaskTaskRunner(
cluster_class=fargate_cluster
))
def test_cluster():
flow...
David Martin Calalang
07/03/2025, 2:37 PMNate
07/03/2025, 2:37 PMcluster_class
instead of a classNate
07/03/2025, 2:38 PMcluster_kwargs
I would thinkNate
07/03/2025, 2:38 PMMarvin
07/03/2025, 2:38 PMNate
07/03/2025, 2:39 PMMarvin
07/03/2025, 2:39 PMprefect-dask
. Here's what you need to know:
1. First, install the package:
bash
pip install prefect-dask
2. Then import and use it as:
python
from prefect_dask import DaskTaskRunner
The DaskTaskRunner accepts several key configuration options:
- `cluster_kwargs`: Dictionary of kwargs to pass to the Dask cluster
- `adapt_kwargs`: Dictionary of kwargs for cluster adaptation (auto-scaling)
- `client_kwargs`: Dictionary of kwargs to pass to the Dask client
- `cluster_class`: The class of Dask cluster to use (defaults to LocalCluster if not specified)
A typical configuration might look like:
python
from prefect_dask import DaskTaskRunner
runner = DaskTaskRunner(
cluster_kwargs={"n_workers": 2},
adapt_kwargs={"minimum": 1, "maximum": 4}
)
@flow(task_runner=runner)
def my_flow():
# your flow code here
pass
Given your interest in container-based deployments, you might want to consider using Dask's ECSCluster
for AWS ECS integration. This would allow you to dynamically spin up Dask workers in your ECS environment.
For more details and the latest documentation, visit:
https://prefecthq.github.io/prefect-dask/
Would you like me to dig deeper into any specific aspect of the DaskTaskRunner configuration, particularly around ECS integration?David Martin Calalang
07/03/2025, 2:40 PM@flow(task_runner=DaskTaskRunner(
cluster_class="dask_cloudprovider.aws.FargateCluster",
cluster_kwargs={kwargs}
))
But I saw the same result, hence why I tried being more specific and passing in the cluster/callable as the class.David Martin Calalang
07/03/2025, 2:41 PMcluster_class
from this github issue on the repository, specifically Anna Geller's implementationDavid Martin Calalang
07/03/2025, 2:47 PMDavid Martin Calalang
07/03/2025, 2:53 PMMarvin
07/03/2025, 2:53 PMMarvin
07/03/2025, 2:54 PMbash
pip install prefect-dask "dask-cloudprovider[aws]" dask
2. Here's how to configure the DaskTaskRunner with ECS:
python
from prefect_dask import DaskTaskRunner
from dask_cloudprovider.aws import FargateCluster
runner = DaskTaskRunner(
cluster_class=FargateCluster,
cluster_kwargs={
"image": "daskdev/dask:latest", # You can customize this
"n_workers": 2,
"fargate_use_private_ip": False, # Set to True if using private subnets
"aws_region": "your-region", # e.g., "us-east-1"
"environment": {
"AWS_PROFILE": "${AWS_PROFILE}", # This will use your environment variable
}
},
adapt_kwargs={
"minimum": 1,
"maximum": 10
}
)
@flow(task_runner=runner)
def your_flow():
# your flow code here
pass
3. For AWS credentials, since you're using AWS_PROFILE, there are several approaches you can take:
a. Environment Variables (Your current approach):
python
# The environment section in cluster_kwargs above will handle this
# Make sure AWS_PROFILE is set in your environment
b. Alternatively, you can use explicit credentials:
python
cluster_kwargs={
# ... other kwargs ...
"environment": {
"AWS_ACCESS_KEY_ID": "your-access-key",
"AWS_SECRET_ACCESS_KEY": "your-secret-key",
"AWS_SESSION_TOKEN": "your-session-token", # if using temporary credentials
}
}
4. Important considerations:
- Ensure your IAM role/user has the necessary permissions for ECS operations. The minimum required permissions include:
- ecs:CreateCluster
- ecs:RegisterTaskDefinition
- ecs:RunTask
- ecs:DescribeTasks
- ecs:ListTasks
- iam:GetRole
- iam:PassRole
- ec2:DescribeSubnets
- ec2:DescribeVpcs
- ec2:DescribeSecurityGroups
- If you're running in a VPC, make sure to configure:
- Proper subnet access
- Security group rules
- NAT Gateway or VPC Endpoints for private subnets
5. Container Image Considerations:
- The default daskdev/dask:latest
image should work for basic operations
- For custom dependencies, you might need to build your own image based on the Dask image
- Ensure your image has all the required Python packages installed
If you run into any issues with task deserialization (which can happen), you might need to ensure that:
1. All dependencies are consistently installed across your local environment and the Dask workers
2. The Python versions match between your local environment and the workers
3. Any custom objects you're passing to tasks are properly serializable
Would you like me to elaborate on any of these aspects, particularly around the container image configuration or IAM roles setup?Nate
07/03/2025, 2:56 PMDavid Martin Calalang
07/03/2025, 3:02 PMNate
07/03/2025, 3:05 PMNate
07/03/2025, 3:13 PMDavid Martin Calalang
07/03/2025, 3:14 PMdask_cloudprovider.aws
library directly.
Am I correct in understanding that by "allow[ing] all cluster options supported by the upstream", this means that whatever parameters that are accepted/needed by the dask_cloudprovider.aws
function that I'm using (FargateCluster in this case) can be passed in the cluster_kwargs
field in the Prefect dask task runner?Nate
07/03/2025, 3:15 PM