About four days ago, my Azure Function timer triggers just ceased to operate without any warning. I had three functions that were functioning throughout the day, but now none are triggering automatically according to the cron schedule.
Although my app remains operational and HTTP triggers are still working fine, all timer triggers have gone silent. There has been no indication of invocation, and the logs are completely empty—it's as if they just decided to stop working altogether. I haven't changed anything on my end.
I attempted to manually run them using the master key, following instructions I found, but I'm getting a 404 error, something that used to work for me consistently. I'm at a loss as to why these functions have stopped functioning; they don't see much action and typically run around six times a day for approximately eight minutes each.
I later figured out that the root of the problem was related to the Cron syntax; it started rejecting the format I was using, which hadn't changed in over six months. I had to adjust the syntax from `* * * * *` to `* * * * * *` by adding seconds for it to work again. It's frustrating how Azure seems to make changes without notifying users.
3 Answers
Have you checked if there’s an 'Always On' feature enabled? Sometimes functions stop if not kept alive, especially if you’re on a consumption plan. But, this has been a common issue where functions don’t trigger just because of the server settings. Let me know what you find!
Totally understand your frustration! I had the same issue—the Cron format seems to change without warning. It's bewildering and can be a real hassle trying to keep up with these updates.
I think 'Always On' is crucial for dedicated plans, but on a dynamic plan, you might not have that option. Maybe double-check if that's impacting your triggers? And, yeah, the recent issues with Cron syntax are pretty annoying.
When did the 'Always On' feature become necessary? I’m also on the dynamic plan, and I thought that wasn't a requirement since it's been working fine for a while.