In both Prefect 2.0 and 3.0, task caching allows you to reuse the results of tasks that might be costly to reproduce with every flow, making your workflows more efficient and ensuring the idempotency of your pipelines.
### Prefect 2.0 Caching
Tasks in Prefect 2.0 support caching their return values, which can be reused in subsequent runs. However, the specific storage location (e.g., disk, memory, or cloud storage) is not detailed in the documentation excerpts available. Typically, the caching mechanism would involve some form of result persistence, likely configured by the user with the openness of the Prefect infrastructure in mind.
Source for Prefect 2.0 caching:
Prefect 2.0 Task Caching Docs
### Prefect 3.0 Caching
In Prefect 3.0, task caching is implemented with specific configurations that hash based on:
- The inputs provided to the task
- The code definition of the task
- The prevailing flow run ID, or task run ID if executed autonomously
These hashed values form a task's cache key. By default, calling the same task with the same inputs more than once within a flow will result in the cached behavior for all calls after the first. However, this caching also relies on result persistence, and the default setting for this is off. Again, the result persistence usually involves external storage and can be configured based on the user's infrastructure.
Source for Prefect 3.0 caching:
Prefect 3.0 Task Caching Docs
In both versions, it's important to configure your environment, such as Kubernetes, with the necessary storage options that meet your caching and persistence needs, since Prefect's open-source configuration allows for flexibility and remote execution scenarios.