I did not see the clear explanation there : http://airflow.incubator.apache.org/concepts.html?highlight=provide_context#latest-run-only
All good! On Wed, Mar 22, 2017 at 2:22 PM, Vincent Poulain < vincent.poul...@tinyclues.com> wrote: > Sid, in your example what is the difference between using the > LatestOnlyOperator & set catch_up feature to False ? "[The catch up > feature] kick off a DAG Run for any interval that has not been run" > I am still learning Airflow concepts too.. > > Thanks! > > On Tue, Mar 21, 2017 at 10:31 PM, Ruslan Dautkhanov <dautkha...@gmail.com> > wrote: > >> Thank you for the detailed explanation Boris. >> >> >> Best regards, >> >> Ruslan Dautkhanov >> >> On Mon, Mar 20, 2017 at 12:12 PM, Boris Tyukin <bo...@boristyukin.com> >> wrote: >> >> > depends_on_past is looking at previous task instance which sounds the >> same >> > as "latestonly" but the difference becomes apparent if you look at this >> > example. >> > >> > Let's say you have a dag, scheduled to run every day and it has been >> > failing for the past 3 days. The whole purpose of that dag is to >> populate >> > snapshot table or do a daily backup. If you use depends on past, you >> would >> > have to rerun all missed runs or mark them as successful eventually >> doing >> > useless work (3 daily snapshots or backups for the same data). >> > >> > LatestOnly allows you to bypass missed runs and just do it once for most >> > recent instance. >> > >> > Another difference, depends on past is tricky if you use BranchOperator >> > because some branches may not run one day and run another - it will >> really >> > mess up your logic. >> > >> > On Mon, Mar 20, 2017 at 12:45 PM, Ruslan Dautkhanov < >> dautkha...@gmail.com> >> > wrote: >> > >> > > Thanks Boris. It does make sense. >> > > Although how it's different from depends_on_past task-level parameter? >> > > In both cases, a task will be skipped if there is another TI of this >> task >> > > is still running (from a previous dagrun), right? >> > > >> > > >> > > Thanks, >> > > Ruslan >> > > >> > > >> > > On Sat, Mar 18, 2017 at 7:11 PM, Boris Tyukin <bo...@boristyukin.com> >> > > wrote: >> > > >> > > > you would just chain them - there is an example that came with >> airflow >> > > 1.8 >> > > > https://github.com/apache/incubator-airflow/blob/master/ >> > > > airflow/example_dags/example_latest_only.py >> > > > >> > > > so in your case, instead of dummy operator, you would use your >> Oracle >> > > > operator. >> > > > >> > > > Does it make sense? >> > > > >> > > > >> > > > On Sat, Mar 18, 2017 at 7:12 PM, Ruslan Dautkhanov < >> > dautkha...@gmail.com >> > > > >> > > > wrote: >> > > > >> > > > > Is there is a way to combine scheduling behavior operators (like >> > this >> > > > > LatestOnlyOperator) >> > > > > with a functional operator (like Oracle_Operator)? I was thinking >> > > > multiple >> > > > > inheritance would do,like >> > > > > >> > > > > > class Oracle_LatestOnly_Operator (Oracle_Operator, >> > > LatestOnlyOperator): >> > > > > > ... >> > > > > >> > > > > I might be overthinking this and there could be a simpler way? >> > > > > Sorry, I am still learning Airflow concepts... >> > > > > >> > > > > Thanks. >> > > > > >> > > > > >> > > > > >> > > > > -- >> > > > > Ruslan Dautkhanov >> > > > > >> > > > > On Sat, Mar 18, 2017 at 2:15 PM, Boris Tyukin < >> bo...@boristyukin.com >> > > >> > > > > wrote: >> > > > > >> > > > > > Thanks George for that feature! >> > > > > > >> > > > > > sure, just created a jira on this >> > > > > > https://issues.apache.org/jira/browse/AIRFLOW-1008 >> > > > > > >> > > > > > >> > > > > > On Sat, Mar 18, 2017 at 12:05 PM, siddharth anand < >> > san...@apache.org >> > > > >> > > > > > wrote: >> > > > > > >> > > > > > > Thx Boris . Credit goes to George (gwax) for the >> implementation >> > of >> > > > the >> > > > > > > LatestOnlyOperator. >> > > > > > > >> > > > > > > Boris, >> > > > > > > Can you describe what you mean in a Jira? >> > > > > > > -s >> > > > > > > >> > > > > > > On Fri, Mar 17, 2017 at 6:02 PM, Boris Tyukin < >> > > bo...@boristyukin.com >> > > > > >> > > > > > > wrote: >> > > > > > > >> > > > > > > > this is nice indeed along with the new catchup option >> > > > > > > > https://airflow.incubator.apache.org/scheduler.html# >> > > > > > backfill-and-catchup >> > > > > > > > >> > > > > > > > Thanks Sid and Ben for adding these new options! >> > > > > > > > >> > > > > > > > for a complete picture, it would be nice to force only one >> dag >> > > run >> > > > at >> > > > > > the >> > > > > > > > time. >> > > > > > > > >> > > > > > > > On Fri, Mar 17, 2017 at 7:33 PM, siddharth anand < >> > > > san...@apache.org> >> > > > > > > > wrote: >> > > > > > > > >> > > > > > > > > With the Apache Airflow 1.8 release imminent, you may >> want to >> > > try >> > > > > out >> > > > > > > the >> > > > > > > > > >> > > > > > > > > *LatestOnlyOperator.* >> > > > > > > > > >> > > > > > > > > If you want your DAG to only run on the most recent >> scheduled >> > > > slot, >> > > > > > > > > regardless of backlog, this operator will skip running >> > > downstream >> > > > > > tasks >> > > > > > > > for >> > > > > > > > > all DAG Runs prior to the current time slot. >> > > > > > > > > >> > > > > > > > > For example, I might have a DAG that takes a DB snapshot >> > once a >> > > > > day. >> > > > > > It >> > > > > > > > > might be that I paused that DAG for 2 weeks or that I had >> set >> > > the >> > > > > > start >> > > > > > > > > date to a fixed data 2 weeks in the past. When I enable my >> > > DAG, I >> > > > > > don't >> > > > > > > > > want it to run 14 days' worth of snapshots for the current >> > > state >> > > > of >> > > > > > the >> > > > > > > > DB >> > > > > > > > > -- that's unnecessary work. >> > > > > > > > > >> > > > > > > > > The LatestOnlyOperator avoids that work. >> > > > > > > > > >> > > > > > > > > https://github.com/apache/incubator-airflow/commit/ >> > > > > > > > > edf033be65b575f44aa221d5d0ec9ecb6b32c67a >> > > > > > > > > >> > > > > > > > > With it, you can simply use >> > > > > > > > > latest_only = LatestOnlyOperator(task_id='latest_only', >> > > dag=dag) >> > > > > > > > > >> > > > > > > > > instead of >> > > > > > > > > def skip_to_current_job(ds, **kwargs): >> > > > > > > > > now = datetime.now() >> > > > > > > > > left_window = kwargs['dag'].following_ >> > > > > > schedule(kwargs['execution_ >> > > > > > > > > date']) >> > > > > > > > > right_window = kwargs['dag'].following_ >> > > schedule(left_window) >> > > > > > > > > logging.info(('Left Window {}, Now {}, Right Window >> > > > > > > > > {}').format(left_window,now,right_window)) >> > > > > > > > > if not now <= right_window: >> > > > > > > > > logging.info('Not latest execution, skipping >> > > > downstream.') >> > > > > > > > > return False >> > > > > > > > > return True >> > > > > > > > > >> > > > > > > > > short_circuit = ShortCircuitOperator( >> > > > > > > > > task_id = 'short_circuit_if_not_current_job', >> > > > > > > > > provide_context = True, >> > > > > > > > > python_callable = skip_to_current_job, >> > > > > > > > > dag = dag >> > > > > > > > > ) >> > > > > > > > > >> > > > > > > > > -s >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > >> > > >> > >> > > > > -- > > > > *Vincent Poulain* > > Senior Software Engineer > > > > Office +33 1 75 50 67 26 <+33%201%2075%2050%2067%2026> | Mobile +33 6 21 > 82 87 62 | vinc...@tinyclues.com <supp...@tinyclues.com> > > Tinyclues | 51 rue Étienne Marcel, 75001 Paris > > www.tinyclues.com <http://bit.ly/2hNL4Fs> | @tinyclues > <https://twitter.com/Tinyclues> > -- *Vincent Poulain* Senior Software Engineer Office +33 1 75 50 67 26 <+33%201%2075%2050%2067%2026> | Mobile +33 6 21 82 87 62 | vinc...@tinyclues.com <supp...@tinyclues.com> Tinyclues | 51 rue Étienne Marcel, 75001 Paris www.tinyclues.com <http://bit.ly/2hNL4Fs> | @tinyclues <https://twitter.com/Tinyclues>
