David Martin Calalang
07/15/2025, 8:46 PMdask-ecs
log groupMarvin
07/15/2025, 8:46 PMMarvin
07/15/2025, 8:47 PMMarvin
07/15/2025, 8:48 PMdask-ecs
log group in CloudWatch as you've noticed.
2. While you can't automatically create a new log group per flow run through Prefect's built-in configuration, you have a few potential workarounds:
a. You can modify the log group configuration when creating the FargateCluster by specifying custom container definitions. This would need to be done in your cluster configuration.
b. You could create a custom logging configuration that includes the flow run ID in the log stream name within the existing log group, which would help with organization.
Here's a basic example of how you might customize the logging configuration:
python
from dask_cloudprovider.aws import FargateCluster
from prefect import task, flow
from prefect_dask.task_runners import DaskTaskRunner
def create_fargate_cluster(n_workers=2):
return FargateCluster(
n_workers=n_workers,
container_definitions=[{
# Your existing container definition settings
'logConfiguration': {
'logDriver': 'awslogs',
'options': {
'awslogs-group': f'your-custom-log-group-name',
'awslogs-region': 'your-region',
'awslogs-stream-prefix': 'dask'
}
}
}]
)
@flow(task_runner=DaskTaskRunner(
cluster_class=create_fargate_cluster,
cluster_kwargs={"n_workers": 2}
))
def your_flow():
# Your flow code here
pass
Important notes:
1. You'll need to ensure your ECS task role has the appropriate permissions to create and write to CloudWatch log groups if you want to use custom log groups.
2. The exact configuration might need to be adjusted based on your specific AWS setup and requirements.
3. Be aware that creating new log groups for each flow run could have cost implications and require additional CloudWatch log group management.
If you really need separate log groups per flow run, you might need to implement a custom solution that:
1. Creates a new log group before the flow run starts
2. Passes that log group name to your Dask cluster configuration
3. Handles cleanup of old log groups according to your retention requirements
Would you like me to provide more specific details about any of these approaches, or would you like to explore a particular solution further?David Martin Calalang
07/15/2025, 8:51 PMcontainer_definitions
, is this related to the image
cluster_kwarg that can be passed in? If I'm passing in a custom image, could I add these log configurations to that image I'm using?Marvin
07/15/2025, 8:51 PMMarvin
07/15/2025, 8:51 PMimage
parameter) vs Container Definitions:
- The image
parameter specifies WHAT container image to use (the actual Docker image)
- container_definitions
specify HOW the container should run (including environment, logging, resources, etc.)
- These are separate concerns - logging configuration cannot be embedded in the image itself
2. Container Definitions vs Docker Image:
- Docker image: Contains your code, dependencies, and filesystem
- Container definitions: Runtime configuration that ECS uses to determine how to run containers
- Logging configuration belongs in container definitions because it's about how the container interfaces with AWS services
Here's an example to illustrate:
python
from dask_cloudprovider.aws import FargateCluster
from prefect_dask.task_runners import DaskTaskRunner
def create_fargate_cluster(n_workers=2):
return FargateCluster(
n_workers=n_workers,
image="your-custom-image:latest", # WHAT to run
container_definitions=[{
# HOW to run it
'logConfiguration': {
'logDriver': 'awslogs',
'options': {
'awslogs-group': 'your-custom-log-group',
'awslogs-region': 'your-region',
'awslogs-stream-prefix': 'dask'
}
},
# Other container configuration options
'memory': '4096',
'cpu': '1024',
# ... other settings
}]
)
@flow(task_runner=DaskTaskRunner(
cluster_class=create_fargate_cluster,
cluster_kwargs={"n_workers": 2}
))
def your_flow():
# Your flow code here
pass
Important points:
1. You cannot embed the CloudWatch logging configuration in your custom image - it must be specified in the container definitions
2. The custom image you're using will still respect the logging configuration specified in the container definitions
3. If you need to modify logging behavior that happens INSIDE your application, that would go in your custom image
4. The container definitions control how ECS handles the container's logs at the platform level
Would you like me to provide more specific details about what can be configured in container definitions, or would you like to explore how to combine custom images with specific logging configurations?