https://prefect.io logo
Join Slack
Powered by
Hi folks, I'm trying to figure out the simplest an...
# ask-community
t
Hi folks, I'm trying to figure out the simplest and least expensive way to get my first Prefect flow into production. Am I correct in thinking I could just spin up a Digital Ocean $5/mo droplet, install 
prefect
on it, copy my workflow repo onto it, 
prefect login
to prefect cloud, and then have systemd run 
prefect agent start
? Or do I need to add a 'process block'?
r
Oracle cloud give you free vm's https://www.oracle.com/uk/cloud/free/
but yeah systemd your agent like you say
t
Thanks. Currently trying to get it working on fly.io as well, though that's a bit more complex
Unfortunately, for both digital ocean and inside a container, I'm getting 
prefect.exceptions.MissingResult
errors 😞
r
on the back of what?
t
The result was not persisted and is no longer available.
I'm assuming it's because I haven't configured a 'storage' block, but I'm struggling to wrap my head around why I'd need to in this simple setup. Here's my deployment config, if that helps (thanks so much for your time with this) https://gist.github.com/timwis/2e6aa51b803839a77229beea3342c777
r
are you trying to persist the result in the flow constructor
t
Nope
Just added my flow code to that gist
r
perhaps the flow crashed and it is trying to persist results so it doesn't have to rerun
t
oh, that's interesting. It probably did crash. But why does it have a problem persisting the results on the VM, but not on my laptop? 🤔
r
its just that you have not configured where to persist
so its defaulted to none, the error is just saying it hasnt saved anything
t
Interesting... does that mean I need to define it in the 
storage
section of the deployment.yaml file? Or in the python code, when I call the flow? (like this https://docs.prefect.io/concepts/results/?h=persistence#result-storage-location)
r
The storage is where it downloads flows from
what you need is result_storage on the flow
t
Thanks, but above that (here), it says:
The result storage location can be configured with the 
result_storage
option. The 
result_storage
option defaults to a null value, which infers storage from the context. Generally, this means that tasks will use the result storage configured on the flow unless otherwise specified. If there is no context to load the storage from and results must be persisted, results will be stored in the path specified by the 
PREFECT_LOCAL_STORAGE_PATH
setting (defaults to 
~/.prefect/storage
).
My take-away from that is that, if I don't specificly specify a result storage option, it will store results in 
~/.prefect/storage
r
so try persist_result:true and leave the storage
that is if you want to do this...first address whats crashing imo
t
Sure, but I want to make sure the system can crash and record the error that's actually causing it to crash, rather than this error 😛
That seems to have helped! I got an error message from one of the APIs I'm hitting.
r
should be logs in prefect cloud on the flow run
t
Thanks for your help
r
No worries, helps me to learn all of this too
2 Views
Open in Slack
PreviousNext
Powered by