@Marvin How to use S3Bucket block as task's result_storage?

To use an S3Bucket block as a task's

result_storage

, follow these steps: 1. Install the relevant library: Ensure you have

prefect-aws

installed. 2. Create and register the block: Register your S3 storage block using Prefect's cloud integration. 3. Reference the block in your flow: Use the

S3Bucket.load

method to load your S3 block. Here's a code example to illustrate:

from prefect import task
from prefect_aws.s3 import S3Bucket

# Load your S3 bucket configuration
my_s3_block = S3Bucket.load("MY_BLOCK_NAME")

@task(result_storage=my_s3_block)
def my_task():
    # task logic here
    pass

This will save the result of the task to the specified S3 bucket instead of storing it in memory. For more details and step-by-step instructions, you can refer to: Prefect Guide on Big Data

@Marvin What is difference between task result caching and persistence?

In Prefect, task result caching and task result persistence serve different purposes: 1. Task Result Caching: - Caching allows tasks to reuse results from previous runs if the inputs are the same. This saves time and compute resources. - It requires task result persistence because the results need to be stored and retrieved for future comparisons. - Example: If you enable caching for a task with a specific cache key and expiration, Prefect will reuse the result if the task is called again within the expiration period. 2. Task Result Persistence: - Persistence is the act of storing the task's result outside the memory, such as in a database or cloud storage. - This is necessary for features like retries, where results need to be available beyond the immediate run of the task. - By default, persistence is enabled automatically if a Prefect feature requires it (like caching or retries). It can also be manually controlled via parameters. Links for detailed information: Prefect Concepts: Results These links explain how to toggle result persistence and how caching works in practical scenarios.

@Marvin Does cache_expiration affect persisted result in storage? If not, then how to delete persisted results from storage after specified time?

The

cache_expiration

parameter in Prefect does not directly affect the deletion of persisted results in storage. It only controls how long the cached result should be considered valid for reuse in subsequent runs. To delete persisted results from storage after a specified time, you need to implement a custom cleanup mechanism. This could be a separate process or task that periodically deletes old results based on your specified criteria. Unfortunately, Prefect does not provide built-in functionality for automatically deleting persisted results after a certain period. You might need to integrate with the storage provider's lifecycle management policies, such as S3's object expiration policies, to handle automatic deletion. For more in-depth details, you can refer to the Prefect Concepts: Results page.