Hello everyone Just wondering if prefect supports adding add

Question

Hello everyone Just wondering if prefect supports adding additional logs to the flow logs I am running a cached task with the following parameters ``` cache key fn=task input hash cache expiration=datetime timedelta hours=2 persist result=True result storage=LocalFileSystem Change to remote in future result serializer=JSONSerializer ``` For every task call I want to log the `cache key` if the task returned the cached result OR if the result were cached Is this supported by prefect by default What are the best practices for this type of logging to be implemented

Filip Panovski · Answer

I m not sure what the Prefect way of doing this would be but perhaps adding a log message inside your actual task would suffice As I understand it the task is not actually run when a cached result is available so nothing should be logged It s not explicit but it s something at least

Deceivious · Answer

Yes that s one of the issue I have Any logging code I write within the task will not be executed I could wrap my own function over `task input hash` to log the `cache key` but I have no way of knowing if the result was returned from the cache or not

Filip Panovski · Answer

Maybe you can have a log at the log levels <https docs prefect io concepts logs logging configuration> I d set everything to e g `DEBUG` and check if the caching layer logs anything additionally If so you could set the log level of only the cache class to `DEBUG`

Deceivious · Answer

Thanks Ill try changing the log level and see if anything else in the logs have changed Also will wait for peeps who have had same issue to comment

Christopher Boyd · Answer

< Deceivious> you can add `print logs=True` to your task flow decorators to add print statements to your log output Additionally `2 7 11` allowed the use of custom loggers

Deceivious · Answer

< Christopher Boyd> this doesn t solve the actual issue I have mentioned Cuz those logs i want are internals of prefects

Christopher Boyd · Answer

I believe it can be retrieved from the task context but if I can t verify that it can be re computed

Christopher Boyd · Answer

it can t be retrieved from task context the task context is used as input

Christopher Boyd · Answer

Deceivious · Answer

< Christopher Boyd> This function is for creating a cache key What I am trying to do is find a way to check if the task result returned was cached or actual result for a task that was run from within the flow

Deceivious · Answer

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Deceivious · Answer

Here are 2 flows the one in left builds the cache and the one in second you can see the cached bubble denoting that the results were from cache I can get these info from UI and API but unsure as to how to get those from within the flow run code itself

Christopher Boyd · Answer

The cache result is stored cloud side so when you re run your flow it computes the cache key then verifies if it matches or does not cloud side

Deceivious · Answer

Yes I understand that the task `state` is stored on the database previously `orion` The result itself is stored in memory OR defined blocks depending on how that task decorators are configured But what I want to know is ```if the flow context has any information on if the called task actually ran or took the result out of the storage cache ``` For example in API the state name field changes based on the state and if the results were cached left pic Cached right pic completed I want to get this in the flow code so i can send a warning if we received cached data

Deceivious · Answer

Also thanks for the patient < Christopher Boyd> smile I know this is a weird use case

Christopher Boyd · Answer

I could be mistaken but isn t this already the case in the agent logs that the task reports it was in a cached state Maybe < Zanie> might have a better understanding here as I believe they helped write the cacheing and docs

Deceivious · Answer

``` 16 19 31 273 | INFO | Task run send request with retry 1 Finished in state Cached type=COMPLETED ```

Deceivious · Answer

I do see the cached log

Christopher Boyd · Answer

I d like to be more helpful here I just don t quite know the answer

Deceivious · Answer

Thanks < Christopher Boyd> I think ive found it Seems like if i use `return state` when calling the task it does seem to have the state name saying it is `Cached` I am not sure if the intentended usage of this name is for this purpose though