tony-brookes commented on issue #16764:
URL: https://github.com/apache/airflow/issues/16764#issuecomment-1195543647

   This one really caught me out the other day as I couldn't see from the 
dependency lines being drawn in the graph view why my tasks were starting with 
their dependencies un-met.
   
   It would seem that for task groups to be totally convenient it shouldn't 
matter when I add the dependency information, the outcome should be the same 
(as others have posted.). Because that's exactly what would happen when you 
link two tasks.  It doesn't matter when you link them or in what order you 
create them.
   
   This looks like it might get a fix some time quite soon but if that is not 
the case perhaps some form of warning logged if tasks are added to groups AFTER 
dependencies have been added would at least alert people that the behaviour 
they expect is unlikely to be what they get. :)
   
   Do like task groups though.  Make things really simple and also lets me 
compose the same set of tasks multiple times in the same DAG by adding a 
different task group around the outside of them and letting the prefix keep 
them uniquely identifiable, which can be really really handy when you are 
programatically generating a DAG from meta data about the files you have been 
given to process. :)


-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]

Reply via email to