Timer Function apps are firing randomly at a late time.

Question

We have timer jobs running on function apps, and we have recently noticed that they are running past the scheduled time on several occasions.

Logs indicate the following message.
UnscheduledInvocationReason: IsPastDue, OriginalSchedule: 2024-04-15T03:30:00.0000000-04:00

In the example above the job ran at 10: 45 am instead of 3:30 am in the morning. It is critical for us to have them on time. We are on consumption plan and have the WEBSITE_TIME_ZONE set to Eastern Standard Time.

The invocation Id for the delayed timer job execution is "6b2423b7-2c01-427e-bff3-4796d02f2268"
Runtime version is 4.33.1.22394
Cron expression is "0 30 3 * * *";

Please let me know if any additional information is required.

Answer 1

@Sharvari H Desai Thanks for reaching out. There could be different reasons for this issue, and I will suggest you review the below document to troubleshoot the issue and see if you are able to find the root cause.

• https://github.com/Azure/azure-functions-host/wiki/Investigating-and-reporting-issues-with-timer-triggered-functions-not-firing
• https://github.com/Azure/azure-webjobs-sdk-extensions/wiki/TimerTrigger#troubleshooting

If you are still facing issue, I would suggest you open a support ticket for in depth analysis to find the root cause of the issue.