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Recurrence is gradually changing it's start time RRS feed

  • Question

  • Hi,

    I have found that recurrences seem to gradually change their start times....i.e. it's not recurring at exactly the same time.  Over the course of a day it ends up losing around 2 minutes.

    e.g. An app is scheduled to run every 5 minutes.  At the beginning of the day the first execution starts at 12:01, but on the next day the first execution starts at 12:03 and so on...adding 2 minutes more each day.

    Is this normal, or a bug?

    Thanks

    Regards, David


    Tuesday, December 3, 2019 4:36 AM

Answers

  • Just checking if you are considering Time Zone setting as well. Also, If you navigate to the Logic App's overview blade in the Azure portal, there should be a section called "Trigger history" on the right-hand side. Do you see "Skipped" entry showing in the list.

    Update :

    1. Instead of using "5/Minutes", you can use "1/Hour" but "At these minutes: 0,5,10,15,20,25,30,35,40,45,50,55" to get the expected behavior. Also if the recurrence is in days or longer, then having a start time specified will also ensure that there’s no drift.

            Or

    1. The logic apps will be scheduled to run based on the recurrence from the last executed time. This recurrence can be off by a second to minute in some cases which will cause this drift. This could be caused by latency in storage calls and other factors. If there is an missing execution because of this, recommendation is to use the sliding window triggerhttps://docs.microsoft.com/en-us/azure/connectors/connectors-native-sliding-window 


    Tuesday, December 3, 2019 5:17 AM
    Moderator

All replies

  • Just checking if you are considering Time Zone setting as well. Also, If you navigate to the Logic App's overview blade in the Azure portal, there should be a section called "Trigger history" on the right-hand side. Do you see "Skipped" entry showing in the list.

    Update :

    1. Instead of using "5/Minutes", you can use "1/Hour" but "At these minutes: 0,5,10,15,20,25,30,35,40,45,50,55" to get the expected behavior. Also if the recurrence is in days or longer, then having a start time specified will also ensure that there’s no drift.

            Or

    1. The logic apps will be scheduled to run based on the recurrence from the last executed time. This recurrence can be off by a second to minute in some cases which will cause this drift. This could be caused by latency in storage calls and other factors. If there is an missing execution because of this, recommendation is to use the sliding window triggerhttps://docs.microsoft.com/en-us/azure/connectors/connectors-native-sliding-window 


    Tuesday, December 3, 2019 5:17 AM
    Moderator
  • Hi,

    Per the below screenshot, you can see that there are no skipped executions. The recurrence is set to 5 minutes, and up until 6:01am it was running at times ending with 1 and 6.  Then it changes to running at times ending with 2 and 7. 

    This is the case where the start times are gradually changing by a few seconds each hour.  This adds up and then at some point the start minute increases by 1.  

    The impact on this is that if the app includes time-sensitive calls to other APIs and you want to get all updated items since the last run, with this issue you can't rely on the start time of each exection as you could miss out on some items due to the seconds of difference.  It's rare but a potential to cause issues / data loss.

    My workaround for the moment is to store the start time in an Azure table each time the apps run and then use this as part of the API query in the next execution.  However if we could rely on the start time always being on schedule then we could just subtract the recurrence amount (5 mins in this case) from the start time.

    Hope this helps clarify.  I don't think timezones have anything to do with this.

    Wednesday, December 4, 2019 12:09 AM
  • Hi DavidC555,

    Thanks for the information and putting across the business case. I definitely want to take this further and need more information from your side. Hence I would recommend you to send an email to AzCommunity[at]Microsoft[dot]com along with the link to this thread and instructions will be sent back for next steps.

    Looking forward for your response.

    Wednesday, December 4, 2019 3:33 AM
    Moderator
  • Thank you - I've sent the email.


    Regards, David

    Wednesday, December 4, 2019 10:13 PM
  • OK, thank you for the updates.


    Regards, David

    Wednesday, December 11, 2019 12:17 AM