<@ULVA73B9P> Can I make that all my prefect tasks ...
# marvin-in-the-wild
e
@Marvin Can I make that all my prefect tasks persist their state to an s3 bucket without having to put arguments in the decorator for all of them?
m
I'll look up information about configuring state persistence to an S3 bucket for Prefect tasks without modifying each task decorator. Let's see what the documentation and GitHub issues have to say about this. To make all your Prefect tasks persist their state to an S3 bucket you can configure a storage block and set it up for your deployment, thus avoiding the need to manually set state persistence in each task decorator. Here's how to approach it: 1. Create an S3 Storage Block: You can define an S3 storage block that specifies where to store the data. 2. Configure Default Storage: Use this storage block as the default for your deployments. Here’s how you can achieve it: ### 1. Create an S3 Storage Block You need to create a storage block to point to your S3 bucket. This might be set up via Python or Prefect CLI. Here’s an example using Python:
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python
from prefect.filesystems import S3

s3_block = S3(
    bucket="your-bucket-name",
    aws_access_key_id="your-access-key-id",
    aws_secret_access_key="your-secret-access-key",
)
s3_block.save("s3-storage-block", overwrite=True)
### 2. Configure Deployment to Use the S3 Storage Block When you build your deployment, you reference this storage block. You can do it through the CLI or programmatically. Below is an example using the
prefect deployment build
command:
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sh
prefect deployment build your_flow.py:your_flow_function --name your-flow --storage-block s3/s3-storage-block
### Documentation Links 1. Persisting Results 2. Deployment Storage These steps ensure that all task states in your flow are persisted to the specified S3 bucket without needing to modify each task individually. If you need more detailed information or have further questions, you might find this deployment guide for Prefect with S3 helpful.
e
@Marvin but would this approach make that the tasks only use the cache on flow retries?
m
Persisting the task states to an S3 bucket using the deployment configuration approach does ensure that task states are saved, which can be helpful in scenarios like flow retries and task caching. However, let's clarify how it works and ensure it meets your requirements for reusing the cache: 1. Persisted Results for Task Retries: By default, Prefect uses persisted results to ensure that upon retrying, the task can continue from where it left off. If the results are stored in S3, Prefect will fetch these results from there during retries. 2. Task Caching: Task caching in Prefect ensures that if the task inputs haven't changed, Prefect can reuse the existing result instead of re-running the task. This mechanism also relies on persisted results. ### Setup for Task Caching and Persistence To ensure tasks are always using the cache (persisted results) effectively, you will want to make sure: 1. Enable Caching for Tasks: This can be done by setting the appropriate caching options within your task decorators. 2. Ensure Persisted Storage is Configured: As mentioned previously, you'll configure your deployment to use S3 as the storage backend. This configuration will automatically ensure that results are persisted to S3. Here's how to enable caching on tasks while ensuring results are persisted to your S3 block, and without explicitly configuring each task to persist results: ### Example Task with Caching:
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python
from prefect import task, flow
from datetime import timedelta

@task(cache_key_fn=lambda *args, **kwargs: "my_unique_cache_key", cache_expiration=timedelta(days=1))
def my_task(param):
    # Task code here
    return f"Processed {param}"

@flow
def my_flow(param):
    my_task(param)

if __name__ == "__main__":
    my_flow("data")
### Setting Up the Deployment: 1. Save the S3 Storage Block:
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python
from prefect.filesystems import S3

s3_block = S3(
    bucket="your-bucket-name",
    aws_access_key_id="your-access-key-id",
    aws_secret_access_key="your-secret-access-key",
)
s3_block.save("s3-storage-block", overwrite=True)
2. Build the Deployment:
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sh
prefect deployment build my_flow.py:my_flow --name my-flow --storage-block s3/s3-storage-block
### Deployment Command for Prefect:
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sh
prefect deployment apply my_flow-deployment.yaml
### Summary: By defining the caching at the task level and ensuring the entire deployment uses S3 for result storage, you achieve two things: - Task results are persisted to S3. - Task caching works as expected, reusing results stored in S3 whenever possible. This approach provides an efficient way of managing and reusing task states without modifying each task decorator to handle state persistence manually.
n
hi @Esteban Vásquez Giraldo
there's a setting for this
PREFECT_DEFAULT_RESULT_STORAGE_BLOCK
which you could set like
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PREFECT_DEFAULT_RESULT_STORAGE_BLOCK=s3/my-bucket-block-name
🙌 1
e
Hi @Nate Thank you so much! I will look into this.
@Marvin My flow failed with the following error: Crash detected! Execution was interrupted by an unexpected exception: ValueError: Bucket create failed 'http:': Parameter validation failed: Invalid bucket name "http:": Bucket name must match the regex "^[a-zA-Z0-9.\-_]{1,255}$" or be an ARN matching the regex "^arn:(aws).:(s3|s3-object-lambda):[a-z\-0-9][0 9]{12}accesspoint[/:][a-zA-Z0-9\-.]{1,63}$|^arn:(aws).*s3 outposts[a-z\-0-9]+[0 9]{12}outpost[/][a zA Z0 9\ ]{1,63}[/]accesspoint[/:][a-zA-Z0-9\-]{1,63}$" How can I fix it?
m
The error arises because the bucket name is being set incorrectly, which violates the validation rules for S3 bucket names. The invalid name "http:" suggests a misconfiguration in the setup of your storage block or a misinterpretation of your parameters. Here’s a step-by-step guide to resolve this: ### 1. Correct Storage Block Definition Ensure that the S3 storage block is correctly defined with the proper AWS credentials and bucket name, and that no extraneous parts like "http:" are included. Here's how you might define an S3 storage block:
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python
from prefect.filesystems import S3

s3_block = S3(
    bucket="your-valid-bucket-name",
    aws_access_key_id="your-access-key-id",
    aws_secret_access_key="your-secret-access-key"
)
s3_block.save("s3-storage-block", overwrite=True)
### 2. Ensure Valid Bucket Name Make sure that the bucket name follows the rules specified by AWS. It should: - Be between 3 and 63 characters long. - Consist only of lowercase letters, numbers, dots (.), and hyphens (-). - Start and end with a letter or number. ### 3. Verify Deployment Configuration Ensure that your deployment configuration properly references this storage block without including additional URL schemes or protocols:
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sh
prefect deployment build my_flow.py:my_flow --name my-flow --storage-block s3/s3-storage-block
### Additional Notes - Make sure you don't include "http:" or "https:" within the bucket name or anywhere it isn't needed. - Double-check your environment variables or configuration files to ensure they are correctly set. ### Example YAML Configuration (Optional) If you're using a YAML configuration file for deployments, ensure it's correctly set up:
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yaml
storage:
  - block: s3/s3-storage-block

deployments:
  - name: my-flow-deployment
    flow: my_flow.py:my_flow
    storage: s3/s3-storage-block
For a comprehensive guide on configuring and using storage blocks in Prefect, check out the Storage documentation. By ensuring these configurations, you should prevent misconfigurations like "http:" from being set as part of the bucket name, and your flow should execute without this error.
e
@Marvin Is http: required within the s3 url?
m
No, "http:" or "https:" is not required or valid within the bucket name itself. The bucket name must adhere strictly to the rules for AWS S3 bucket names, which do not include URL schemes like "http:". Here’s what you need: ### Correct Example: When defining your S3 storage block, ensure you use only the bucket name:
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python
from prefect.filesystems import S3

s3_block = S3(
    bucket="your-valid-bucket-name",
    aws_access_key_id="your-access-key-id",
    aws_secret_access_key="your-secret-access-key"
)
s3_block.save("s3-storage-block", overwrite=True)
### Incorrect Example: DO NOT include "http:" within the bucket name:
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python
# INVALID EXAMPLE - DO NOT USE
s3_block = S3(
    bucket="http:your-invalid-bucket-name",
    aws_access_key_id="your-access-key-id",
    aws_secret_access_key="your-secret-access-key"
)
### Valid URL: When you need to include full URLs (e.g., accessing objects in the bucket), you might use the "https://" schema, but this is separate from identifying the bucket name itself:
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python
# Accessing an object in the bucket
object_url = "<https://your-valid-bucket-name.s3.amazonaws.com/path/to/object>"
### In Summary: - Bucket Name: Should be just the name of your bucket, e.g.,
"your-valid-bucket-name"
. - URL to Access Objects: May include the protocol, but this is separate from the bucket name and generally used within your application logic for accessing objects. Hope this clears up any confusion! Let’s ensure you apply this correctly in your storage block and deployment configurations.