Hi guys What s the proper way of running a one time only sch

Question

Hi guys What s the proper way of running a one time only schedule flow in Orion I can t find the DatesClock class anymore in Orion In Prefect 1 X i was using something like this to start the flow 10 seconds after the registration ```def get schedule schedule str return Schedule clocks= DatesClock pendulum now add seconds=10 if schedule == one time else CronSchedule cron=schedule ``` Thanks

Mason Menges · Answer

Hey < Alexandru Anghel> I m not sure I follow exactly what you re wanting to accomplish here i e what s the Purpose behind scheduling a flow to run only once That said you could potentially use to do this

Alexandru Anghel · Answer

Hey < Mason Menges> thanks for replying I am loading some historical data using hard coded start and end dates so i need some flows to run only once I am looking now at rrules never used it before

Mason Menges · Answer

You might find some use with this functionality for 2 0 then <https github com PrefectHQ prefect blob main src prefect deployments py L40> run deployment allows you to specify the start time and parameters for a flow run deployment directly rather than through the schedule smile

Alexandru Anghel · Answer

Thanks i wil have a look I tried with rrules but i get this error `Invalid RRule string FREQ=DAILY COUNT=1 DTSTART=20221104T220851Z unknown parameter DTSTART type=value error ` Edit Nevermind i ve added by mistake dtstart in the rrule string

Alexandru Anghel · Answer

I don t think rrules are helpful for me From what i understand it s good for repeated schedules which is not my case

Alexandru Anghel · Answer

One workaround would be something like this and hope i won t be around for the next run smiley ```def get schedule schedule str dtstart = datetime now + timedelta 0 10 return IntervalSchedule interval=timedelta days=9999 anchor date = dtstart timezone= UTC if schedule == one time else CronSchedule cron=schedule timezone= UTC ``` Going back to your proposal of setting the parameters directly to the flow run i m not sure this will work for my use case I m using dask runner and relying heavily on flow templates Finally i m declaring the flows through kubernetes manifests It would be really helpful to be able to specify a particular timestamp directly to the schedule like we used to have in Prefect 1 x

Nate · Answer

Hi < Alexandru Anghel> You could use `run deployment` in your CI CD which is not a task so it doesn t need to be in a flow to trigger a given deployment some amount of time after the deployment is applied ```from prefect deployments import run deployment my deployment apply sleep 10 run deployment name= myDeployment params=dict ```

Alexandru Anghel · Answer

Thank you < Nate> This is indeed a better solution

Alexandru Anghel · Answer

The only downside of this is that the pod that launches the deployment is staying in Running state until the dask pods complete their tasks

Nate · Answer

You can pass `run deployment name= xxx xxx timeout=0 ` to avoid waiting for the referenced deployment to run