Difference between 'always' and 'only one' Autosubmit options in Wait event
I tested some jobs with 'always' and 'only one' Autosubmit options by placing some files. Whenever the file is placed, the instance of the job is getting submitted irrespective of the previous instance of the job is running or not.
Can one please explain is there any much difference between the two options 'always' and 'only one' Autosubmit options in Wait event tab.
Gerben Blom replied
In your scenario 'Only One' should behave the same as 'Always'. However, due to timing issues in the 'Only One' case it is possible that the previous job is not started quickly enough by the system, in that case, it will see a pre-running job, causing the Autosubmit NOT to happen. Now no additional job is started that can clear the Raised event. And now the process gets stuck as there is an event in status Raised, and all new files will put their Event in status Pending until the Raised Event gets cleared, which will never happen. So here you want to avoid using the 'Only One' option but use 'Always' instead.
The only reason to use 'Only One' (and still you might run into this deadlock scenario due to timing issues) is when the job waiting on the file is sometimes already Scheduled/Waiting/EventWait and sometimes has to be started by the File Event. Because when the job is already waiting, the Always will kick off the waiting job AND autosubmit a new job.