Control Room & Scheduler

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Missed Task in a Schedule

  • 1.  Missed Task in a Schedule

    Posted 08-15-2019 09:12
    ​Hi,

    I have a schedule that runs daily which is set to run the Login Agent as task 1 then on both completion and exception it runs task 2, and again on completion or exception of that it should run task 3.

    The schedule has been running fine for weeks now but this morning it ran the login agent but then jumped to task 3. Has anybody experienced this before? Is there anything I can do to prevent this happening again?

    I'm on version 6.4.2

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    Emma Burns
    Ground Control Ltd

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  • 2.  RE: Missed Task in a Schedule

    Posted 08-15-2019 11:36
    Edited by David Morris 08-15-2019 11:38
    Because you have Task 2 calling Task 3 on completion or exception, Task 2 could seem to be skipped at times. The reason this could happen is if something prevents Task 2 from running. I'm not sure how to guess what caused Task 2 not to start for you, but I'd say that it's impossible for Blue Prism to actually skip the task entirely. Most likely the app server sent instructions to the resource for Task 2 to begin after Task 1 and when it failed to start, Task 3 ran immediately after that.

    An example of a time that this could happen is if you have Task 2 run on Runtime Resource 1 and Task 3 is supposed to start after Task 2 but this time on Runtime Resource 2. Regardless of whether Task 2 is successful, Task 3 will start on Runtime Resource 2. The reason this might happen is if Runtime Resource 1 is busy at the time the call is made for Task 2 to begin, such as an exclusive mode session running on Runtime Resource 1 already.

    You may have found a bug, but verify that the schedule is still configured as it has been for weeks. Yesterday, I created a schedule and forgot to set Task 1 to call Task 2 on completion. It stumped me at first until I realized I just made a silly mistake and forgot to specifically choose the on complete and on exception drop downs for each Task.

    It sounds like what I've described is not your issue, but it would be good to verify it again just in case Task 1 is calling Task 3 now.

    Edit: I'd suggest changing the Login Agent action to not fail if the runtime resource is logged in already and then change your schedule so that it only runs the next task on completion. 

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    Dave Morris
    3Ci @ Southern Company
    Atlanta, GA
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  • 3.  RE: Missed Task in a Schedule

    Posted 08-15-2019 12:00
    Thank you for your reply.

    On looking into the logs for the schedule I saw that it did in fact attempt task 2 as scheduled, but it threw an exception saying that No Sessions were successfully created. I still would have expected to see a failed line in the Control Room for this task though.

    "Failed to create session on RESOURCENAME  - COMMAND NOT VALID AT THIS TIME - RESOURCE IS STOPPING (WAITING FOR RUNNING SESSIONS TO COMPLETE)"

    I too have fallen down at forgetting to set the next task in a schedule - you'd think it would automatically go on to the next item in the list!

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    Emma Burns
    Ground Control Ltd

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  • 4.  RE: Missed Task in a Schedule

    Posted 08-15-2019 12:06
    I agree that it'd be nice to see that failed attempt in Control Room. I suspect the reason it doesn't put a line in Control Room is that Scheduler will retry items for a period of time, and it could really clutter up Control Room if every attempt was put it and showed as terminated. That would also require a change to how Blue Prism works because a session ID isn't assigned until the session is created so if it never starts there's no session ID so it couldn't exist in the same table as the rest of the entries shown in Control Room.

    Do you have a good 100+ second post completion delay on your Login task before Task 2 runs? I suppose that could cause the issue as well if Task 2 failed to run because the resource was not quite logged in. I can't imagine it saying that error though. I'd just try increasing that post completion delay and see if the error ever happens again.

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    Dave Morris
    3Ci @ Southern Company
    Atlanta, GA
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