<@ULVA73B9P> we are currently dealing with a scena...
# ask-community
s
@Marvin we are currently dealing with a scenario where i'll having a deployment and that deployment will have one of the parameter called cfg where it will contains a string value which is dev1 which will automatyically connects to a /server/cfg/setup/dev1.cfg file and inside that file i have a configuration which will containes a ads server hostname that particular task connects to and execute the task. Now i want to move this part from deploymnet tlevel to workpool level. Because i have 6 ads's and i want to have these 6 ads's as 6 workpools so that i can connect to what ever pool i want while acalling run_deployment() and share the load. For example i have 1000'f of runs but the ads can handle only 200 connections at a time so this case i will add workpool concurranct so that the case will be achieved. is there any way to fullfill my scenario?
m
thought for 15.1 seconds
Let me help you with this scenario. This is a great use case for workpools and their configuration capabilities in Prefect. Here's how you can restructure your setup to move from deployment-level to workpool-level configuration: 1. First, create separate workpools for each ADS server. You can do this either via the UI or using the CLI:
Copy code
bash
prefect workpool create "ads-pool-1" --type process
prefect workpool create "ads-pool-2" --type process
# ... and so on for all 6 ADS servers
2. For each workpool, you can set base configuration using workpool settings. Instead of reading from
/server/cfg/setup/dev1.cfg
, you can set the ADS hostname directly in the workpool configuration:
Copy code
python
from prefect.client import get_client

async def configure_workpool():
    client = get_client()
    await client.update_workpool(
        "ads-pool-1",
        base_job_template={
            "env": {
                "ADS_HOSTNAME": "<http://ads1.example.com|ads1.example.com>"  # Your actual ADS hostname
            }
        }
    )
3. Modify your flow to read the ADS hostname from environment variables instead of the config file:
Copy code
python
import os
from prefect import flow

@flow
def your_flow(other_params):
    ads_hostname = os.environ.get("ADS_HOSTNAME")
    # Your logic using ads_hostname
    ...
4. When deploying your flow, you no longer need the cfg parameter:
Copy code
python
from prefect import flow
from prefect.deployments import Deployment

@flow
def your_flow(other_params):
    ...

deployment = Deployment.build_from_flow(
    your_flow,
    name="your-deployment",
    # Remove the cfg parameter since it's now handled by workpool
)
5. To handle the connection limits (200 connections per ADS), set the concurrency limits on your workpools:
Copy code
bash
prefect workpool update ads-pool-1 --concurrency-limit 200
6. When running deployments, you can now specify which workpool to use:
Copy code
python
from prefect.client import get_client

async def run_deployment():
    client = get_client()
    deployment_id = await client.create_deployment_run(
        "your-flow/your-deployment",
        workpool_name="ads-pool-1"  # Specify which ADS pool to use
    )
This setup gives you several advantages: 1. Load Distribution: You can distribute your 1000+ runs across multiple ADS servers by using different workpools 2. Connection Management: Each workpool's concurrency limit ensures you don't exceed the 200 connection limit per ADS 3. Configuration Isolation: Each workpool has its own configuration, making it easier to manage different ADS servers 4. Dynamic Selection: You can choose which ADS server to use at runtime by selecting the appropriate workpool For monitoring, you can use the Prefect UI to see how many runs are currently executing on each workpool and manage the workload distribution. Remember to adjust the concurrency limits based on your actual system capabilities and requirements. You might want to set it slightly lower than 200 to leave some headroom for other connections. This approach gives you more flexibility and better resource management than handling it at the deployment level, and it's more maintainable as you can update ADS configurations without modifying your deployments.
s
so here my .cfg file will include setting some config vaiables and also using export command and calling other scripts. So can i add these entire things into this base_job_template={ "env": { "ADS_HOSTNAME": "ads1.example.com" # Your actual ADS hostname }?
@Marvin so here my .cfg file will include setting some config vaiables and also using export command and calling other scripts. So can i add these entire things into this base_job_template={ "env": { "ADS_HOSTNAME": "ads1.example.com" # Your actual ADS hostname }?
m
thought for 15.9 seconds
Yes, absolutely! The
base_job_template
can handle complex configurations including environment variables, commands to run before your flow, and other settings. Here's how you can structure it:
Copy code
python
from prefect.client import get_client

async def configure_workpool():
    client = get_client()
    await client.update_workpool(
        "ads-pool-1",
        base_job_template={
            # Environment variables
            "env": {
                "ADS_HOSTNAME": "<http://ads1.example.com|ads1.example.com>",
                "OTHER_CONFIG": "value",
                "CUSTOM_SETTING": "setting_value",
                # Add all your environment variables here
            },
            # Commands to run before the flow starts
            "job_configuration": {
                "prepare_command": [
                    "export MY_VAR=value",
                    "source /path/to/your/script.sh",
                    # Add any other commands that were in your .cfg file
                ]
            }
        }
    )
If you have a lot of configuration, you can make it more manageable by loading it from a dictionary:
Copy code
python
config = {
    "env": {
        "ADS_HOSTNAME": "<http://ads1.example.com|ads1.example.com>",
        "DB_CONNECTION": "connection_string",
        "API_KEY": "your_api_key",
        # ... all your environment variables
    },
    "job_configuration": {
        "prepare_command": [
            "export PATH=$PATH:/additional/path",
            "source /path/to/setup.sh",
            "export CUSTOM_VAR=value",
            # ... all your export commands and script calls
        ]
    }
}

async def configure_workpool():
    client = get_client()
    await client.update_workpool(
        "ads-pool-1",
        base_job_template=config
    )
A few important notes: 1. The
prepare_command
commands run in sequence before your flow starts 2. Each command in
prepare_command
runs in a shell context, so you can use shell features like: - Environment variable expansion (
$VAR
) - Shell script sourcing (
source
or
.
) - Export commands - Piping and redirection 3. If you need to maintain different configurations for different environments, you could create a configuration file for each workpool:
Copy code
python
import yaml

# Load workpool-specific configuration
def load_workpool_config(workpool_name):
    with open(f"configs/{workpool_name}.yaml", "r") as f:
        return yaml.safe_load(f)

async def configure_workpool(workpool_name):
    config = load_workpool_config(workpool_name)
    client = get_client()
    await client.update_workpool(
        workpool_name,
        base_job_template=config
    )
Example YAML configuration (
configs/ads-pool-1.yaml
):
Copy code
yaml
env:
  ADS_HOSTNAME: <http://ads1.example.com|ads1.example.com>
  DB_CONNECTION: connection_string
  API_KEY: your_api_key

job_configuration:
  prepare_command:
    - export PATH=$PATH:/additional/path
    - source /path/to/setup.sh
    - export CUSTOM_VAR=value
This approach gives you: 1. All the configuration capabilities you had with your .cfg files 2. Better organization and separation of concerns 3. Easy management of multiple ADS configurations 4. The ability to version control your configurations 5. A clean way to update configurations without modifying the flows Remember that any sensitive values (like API keys or passwords) should be handled securely, preferably using Prefect Blocks for secrets management rather than storing them directly in these configurations. Also, make sure any scripts or files referenced in your
prepare_command
are accessible in the environment where your flows will run. If you're using remote workers, ensure all necessary files are either in the worker environment or copied there as part of the deployment process.
s
@Marvin so here in that can i add my cfg file in the job configuration so that it will look at that file and set those variables?
m
thought for 3.9 seconds
I apologize, but your question needs more context. You mentioned "that" and "cfg file" but I'm not sure what specific part of Prefect you're working with. Could you please: 1. Explain what configuration you're trying to set up (e.g., flow configuration, deployment configuration, etc.) 2. Describe what type of cfg file you have (is it a .env file, a YAML file, or something else?) 3. Share what variables you're trying to set This will help me provide a more accurate and helpful answer about how to properly configure your Prefect setup.