I'll have to test, bit my gut says that isn't how it works, instead next schedule = previous schedule + interval.
On 20 January 2021 19:25:50 GMT, Elad Kalif <elad...@gmail.com> wrote: >Sorry ignore my explanation. It's wrong. > > https://github.com/apache/airflow/issues/8649 explains why >`schedule_interval=timedelta(days=14), start_date=...`. is not the exactly >the same as bi-weekly for an exact specified time. >It also provide an example for daily. > >On Wed, Jan 20, 2021 at 9:19 PM Elad Kalif <elad...@gmail.com> wrote: > >> > `schedule_interval=timedelta(days=14), start_date=...`. >> >> ash from what I've seen It doesn't give the same exact functionality >> This is what I observed: >> cron = schedule exactly on regardless of what happened with previous run >> (mostly) >> timedelta() = schedule after delta passed. However it's from end_date not >> from start_date. >> so schedule_interval=timedelta(days=14) means It will be scheduled 14 days >> from end_date or the previous run. If we consider for example that the dag >> takes 2 days to complete then the next one will be scheduled after 14 days >> from end_date (= 16 days from start_date). >> >> This exact case is actually explained really well in the first issue >> listed https://github.com/apache/airflow/issues/8649 using daily example >> >> On Wed, Jan 20, 2021 at 9:17 PM Kaxil Naik <kaxiln...@gmail.com> wrote: >> >>> >>> `schedule_interval=timedelta(days=14), start_date=...`. >>> >>> >>> That won't support every second Thursday for example >>> >>> On Wed, Jan 20, 2021 at 6:54 PM Ash Berlin-Taylor <a...@apache.org> wrote: >>> >>>> Running exactly every two weeks can be done by setting >>>> `schedule_interval=timedelta(days=14), start_date=...`. >>>> >>>> Does this do what you need Elad? >>>> >>>> On 20 January 2021 18:12:36 GMT, Elad Kalif <elad...@gmail.com> wrote: >>>>> >>>>> >> In the example of a twice-a-month dag (not sure if it you have this >>>>> use case too?) what do you expect the "data interval" (i.e. >>>>> execution_date) >>>>> to be? >>>>> Yes we have this use case too. The execution date does matter because I >>>>> want it to be bi-weekly for starting specific day and time >>>>> so with the current implementation I expect to provide >>>>> start_date=datetime(2021,1,19,20,5) & schedule_interval='2 weeks' >>>>> >>>>> Currently Airflow has 'hourly', 'daily' , 'weekly' - which doesn't >>>>> allow us to set it. >>>>> So a possible solution for this specific use case could be defining: >>>>> repeat_every - integer that represents the frequency (1,2,3,... n) >>>>> unit - str that provide the "gaps" (minutes, hours, days, weeks, >>>>> months, years) >>>>> Example: bi-weekly / twice a month can be: repeat_every = 2, unit = >>>>> 'weeks' >>>>> To get the 'hourly', 'daily' , 'weekly' functionality it >>>>> just needs to set unit=1. >>>>> >>>>> By the way this is exactly what google calendar allows to set if you >>>>> click on custom scheduling for a meeting. >>>>> >>>>> I'm still in favor of the python function approach as it should cover >>>>> all cases and provide full control for the users. >>>>> >>>>> On Wed, Jan 20, 2021 at 7:20 PM Deng Xiaodong <xd.den...@gmail.com> >>>>> wrote: >>>>> >>>>>> A quick thought (*maybe not making sense*): if *schedule_interval* >>>>>> accepts >>>>>> a list of values, we may support much higher complexity. >>>>>> >>>>>> For example, I may want to schedule my jobs at every days' 04:05 AND >>>>>> 02:31 , which cannot be expressed by single Cron pattern. Then I may want >>>>>> to have *schedule_interval = ["5 4 * * *", "31 2 * * *"]*. >>>>>> >>>>>> Maybe I missed something or the idea doesn't make sense. Please let me >>>>>> know. >>>>>> >>>>>> >>>>>> XD >>>>>> >>>>>> On Wed, Jan 20, 2021 at 6:09 PM Ash Berlin-Taylor <a...@apache.org> >>>>>> wrote: >>>>>> >>>>>>> Yes, we quite possibly could do this -- I'm trying to work out what >>>>>>> the needs are here. >>>>>>> >>>>>>> In the example of a twice-a-month dag (not sure if it you have this >>>>>>> use case too?) what do you expect the "data interval" (i.e. >>>>>>> execution_date) >>>>>>> to be? >>>>>>> >>>>>>> Or for this case does it not matter? >>>>>>> >>>>>>> -ash >>>>>>> >>>>>>> >>>>>>> On Wed, 20 Jan, 2021 at 19:06, Elad Kalif <elad...@gmail.com> wrote: >>>>>>> >>>>>>> Another case that is mentioned in one of the issues is the ability to >>>>>>> schedule a bi-weekly job (equivalent of bi-weekly meeting that you can >>>>>>> set >>>>>>> in a calendar) which is very much needed. >>>>>>> >>>>>>> Maybe this is unrealistic but I think the game changer is if it would >>>>>>> be possible to let the users define their own logic and airflow will >>>>>>> use it >>>>>>> to schedule DAGs. >>>>>>> My thought here is - if I can define the logic in a python function >>>>>>> (regardless of what this logic is). Can't Airflow utilize it? >>>>>>> >>>>>>> On Wed, Jan 20, 2021 at 5:39 PM Ash Berlin-Taylor <a...@apache.org> >>>>>>> wrote: >>>>>>> >>>>>>>> Hi everyone, >>>>>>>> >>>>>>>> I'd like to (re)start the discussion about a new feature I'd like to >>>>>>>> add for Airflow 2.1, that I am loosely calling "improving >>>>>>>> schedule_interval" (catchy name I know!) >>>>>>>> >>>>>>>> I have two main high-level goals in mind here: >>>>>>>> >>>>>>>> 1. To reduce the confusion around execution_date (specifically the >>>>>>>> naming of the parameter!) - the whole start vs end discussion. >>>>>>>> 2. To support more complex schedules. >>>>>>>> >>>>>>>> Previous thread on this point 1 here: >>>>>>>> https://lists.apache.org/thread.html/2b12ae265795ff2e655a5161c972f5c7bbe60722a12849a0e2c5c55f%40%3Cdev.airflow.apache.org%3E, >>>>>>>> (but I'm taking a bit of a step back from that to think if there's a >>>>>>>> bigger >>>>>>>> change we could make that encompases this) >>>>>>>> >>>>>>>> >>>>>>>> I don't yet have a concrete plan, nor implementation in mind, but >>>>>>>> I'd like to start collecting peoples "wish list" when it comes to >>>>>>>> scheduling DAGS: >>>>>>>> >>>>>>>> - What do you wish you could express natively in terms of scheduling >>>>>>>> your DAGs? (I.e. without using "hacks" such as date sensor/skip tasks >>>>>>>> at >>>>>>>> start) >>>>>>>> - What schedules do you wish you could express now, that you just >>>>>>>> can't? >>>>>>>> - Do you have good example workflows that give a good example of >>>>>>>> where you want schedule at start? Follow up question: do you also want >>>>>>>> this >>>>>>>> to be different for different DAGs in your Airflow install? >>>>>>>> >>>>>>>> >>>>>>>> Existing issues: >>>>>>>> https://github.com/apache/airflow/issues/8649 "Add support for more >>>>>>>> than 1 cron exp per DAG" >>>>>>>> https://github.com/apache/airflow/issues/10194 "Ability to better >>>>>>>> support odd scheduling time" >>>>>>>> https://github.com/apache/airflow/issues/10449 "Dynamic Schedule >>>>>>>> Intervals" >>>>>>>> https://github.com/apache/airflow/issues/10123 "Job Schedule >>>>>>>> Interval on 2nd & 4th Tuesday" >>>>>>>> >>>>>>>> I'll start: >>>>>>>> >>>>>>>> Case1: >>>>>>>> >>>>>>>> One example that came up recently in slack was an actual astronomer >>>>>>>> wanting a DAG to run with a schedule of "@sunset"! This also brings up >>>>>>>> the >>>>>>>> subject of "running dags at interval start or end" >>>>>>>> >>>>>>>> Case2: >>>>>>>> >>>>>>>> I'd like to be able to run a daily process at the end of each week >>>>>>>> day. I.e. to process data for Monday..Friday. The naive way of >>>>>>>> expressing >>>>>>>> this would be "0 0 * * MON-FRI", but that means that the dags would run >>>>>>>> Tuesday, Wednesday ,Thursday ,Friday, Monday -- meaning Friday's data >>>>>>>> isn't processed until Monday! >>>>>>>> >>>>>>>> My thoughts on this is we need to separate schedule interval (when >>>>>>>> to run a task) from the period duration (i.e look at one days worth of >>>>>>>> data). >>>>>>>> >>>>>>>> Thanks, >>>>>>>> Ash >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>>
