Is it possible to have a parameter the user could set in the UI to have a flow tell a task to ignore its own cache? e.g. most of the time when a task reruns inside the cached period I want it to use the cache, but every now and then I want it to rerun without it. Currently I just manually delete the cache files before kicking off a run to get this to happen; is there a better way? Ideally maybe a parameter I could pass in from the UI to tell it to ignore the cache this run?

Kind of. You would need to use that

Parameter

as an input into the task, and then create a

cache_validator

based on it. So if the input into the task changes, the cache is be invalidated

I am not. The flow has

LocalResult()

set for

result

Ah ok you use

cache_for

to set it?

Yes

Ah yeah then I would explore using the cache_validator. Yep!

I'm new to parameters in that case though, in the run screen of the UI, is is the

context

field I use to pass in parameters?

No you need to register a parameter in your flow to be able to input it from the UI

Ahh, so once I register it, it'll show up in the run screen

Yes exactly

Cool; that should pretty much give me exactly what I wanted; thanks!!

I think there is

all_inputs

and

all_parameters

. If you have 10 tasks but only want to invalidate one, you need to use

all_inputs

, otherwise all will be invalidated with

all_parameters

right? So yes the task would need to take in an extra input

Got it. And if I'm registering a flow, adding a parameter should make it show up in the UI too? So add the

Parameter

function to the flow itself and add a parameter key to the register command?

flow.register(_project_name_=PROJECT_NAME,_parameters_={'cache_invalid':False},_idempotency_key_=FLOW_NAME)

So far that doesn't seem to be working

Yep!

That worked! Thanks!

sorry to hijack this thread. What's the difference between

target

caching and

cache_for

caching? Is the latter just for anything that is not file-based? This helps with a question I had earlier. I was just going to either 1) write a wrapper that builds a flow with two different decorators, one with

target

and one without, or 2) use

case

conditional to choose whether to use the function decorated with

target = True

or the one with

target = False

. But the cache validator is very interesting and I think it can serve the same purpose. https://prefect-community.slack.com/archives/CL09KU1K7/p1639327736415300

Yes that’s right. They are two forms of caching and

target

is file based, like

cache_for

is recorded in Prefect Cloud as a state