I think you can do something like Azure functions blob storage binding and let that kick off a dag by triggering it from the Rest API:
https://docs.microsoft.com/en-us/azure/azure-functions/functions-bindings-storage-blob <https://docs.microsoft.com/en-us/azure/azure-functions/functions-bindings-storage-blob> I don’t use Azure so it might not fit your case. Bolke > On 23 Oct 2017, at 16:15, Grant Nicholas > <[email protected]> wrote: > > It sounds like you want a background daemon that continuously monitors the > status of some external system and triggers things on a condition. This > does not sound like an ETL job, and thus airflow is not a great fit for > this type of problem. That said, there are workarounds like you mentioned. > One easy workaround if you can handle a delay between `condition happens -> > dag triggers` is setting your controller dag to have a recurring schedule > (ie: not None). Then when that controlling dag is triggered, you just > perform your sensor check once and then trigger/don't trigger another dag > depending on the condition. The thing I'd be worried about with your > `trigger dagrun` approach is if the trigger dagrun operator fails for any > reason you'll stop monitoring the external system, while with the scheduled > approach you don't have to worry about the failure modes of retrying failed > dags/etc. > > On Mon, Oct 23, 2017 at 2:30 AM, Niels Zeilemaker <[email protected]> > wrote: > >> Hi Guys, >> >> I've created a Sensor which is monitoring the number of files in an >> Azure Blobstore. If the number of files increases, then I would like >> to trigger another dag. This is more or less similar to the >> example_trigger_controller_dag.py and example_trigger_target_dag.py >> setup. >> >> However, after triggering the target DAG I would want my controller >> DAG to start monitoring the Blobstore again. But since the schedule of >> the controller DAG is set to None, it doesn't continue monitoring. I >> "fixed" this by adding a TriggerDAG which schedules a new run of the >> Controller DAG. But this feels a bit like a hack. >> >> Does someone have any experience which such a continuous monitoring >> sensor? Or know of a better way to achieve this? >> >> Thanks, >> Niels >>
