Random 404 error on Azure Function

Question

Random 404 error on Azure Function

Anonymous

Hi guys,

Does anyone of you have experience a 404 nginx issue from Azure Function (called made by ADF).

Error message is :
failed with status-'NotFound' and message - '<html> <head><title>404 Not Found</title></head> <body bgcolor="white"> <center><h1>404 Not Found</h1></center> <hr><center>nginx</center> </body> </html>

And I have a loop that is calling the same Function multiple time and occasionally it failed with the error above (majority is succeeding).
Also because the error arrived at NGINX level, no logs on the Azure Function

Pramod Valavala 20,656 Reputation points Microsoft Employee Moderator

2021-05-13T14:16:50.753+00:00

@Anonymous Looks like this issue is similar. Feel free to share your observations there as well to get more insights.

As per this comment, this is expected if the host shuts down for an invocation that goes over the timeout limit. Could you confirm if this is true for your case?
Kiran Pradeep 106 Reputation points

2021-06-14T07:12:15.933+00:00

I see this same exact issue. Not sure what to do.
Anonymous

2021-06-16T23:49:12.603+00:00

In Adf, you can set a retry to 1 or 2 and then if it bumps in a 404 it will retry. However, if your function timeout (sync mode after 4min), you will have the same behavior while it might just executing it stuff in the background.

3 answers

Your answer

Pramod Valavala 20,656 Reputation points Microsoft Employee Moderator

2021-05-13T14:16:50.753+00:00

@Anonymous Looks like this issue is similar. Feel free to share your observations there as well to get more insights.

As per this comment, this is expected if the host shuts down for an invocation that goes over the timeout limit. Could you confirm if this is true for your case?
Kiran Pradeep 106 Reputation points

2021-06-14T07:12:15.933+00:00

I see this same exact issue. Not sure what to do.
Anonymous

2021-06-16T23:49:12.603+00:00

In Adf, you can set a retry to 1 or 2 and then if it bumps in a 404 it will retry. However, if your function timeout (sync mode after 4min), you will have the same behavior while it might just executing it stuff in the background.

Answer 1

Pramod Valavala 20,656 Microsoft Employee Moderator

@Anonymous According to this comment, it is expected for the host to shut down on function timeouts but as covered in another issue, this isn't detected immediately, causing the 404.

Even if you have the max timeout set to 10 minutes (assuming consumption tier), it could still be possible that one of our executions is taking longer. If this is the case, you should be able to confirm the same in the logs as mentioned in the linked issue.

Answer 2

I am also facing this exact same issue when am calling an API endpoint to fetch data and write them in Data Lake. The processing takes around ~7 minutes, but the function throws error in Synapse pipeline within 4 minutes of execution. In some cases, the function completes the processing and write data into Data Lake while at other times it simply don't and the application monitor also don't track any log. As if the execution vanishes without writing any log. This is crazy!

Did anyone find a solution to this?

Btw, even the retry doesn't help @Anonymous

Answer 3

Tommy Ballo 1

We solved this issue by upgrading to Function App version: 4 instead of running on the older V3.

Maybe this will help if anyone has the same issue in the future.

Tommy Ballo

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Random 404 error on Azure Function

3 answers

Your answer