Unavailable backends in azure frontdoor

Deshmukh, Vijit 496

Hi Team,

We are getting message in Azure Front Door under diagnose and solve problem tag.

Message : "Azure monitoring system received the following information regarding your resource km-frontdoor: One or more of your Front Door/CDN profiles backends are responding with errors to health probes. The backends associated with this Front Door/CDN profile are not responding to health probes with the expected status."

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Please guide us to resolve this message error.

KapilAnanth-MSFT 35,001 Reputation points Microsoft Employee

2023-02-22T12:03:02.1533333+00:00
@Deshmukh, Vijit

Welcome to the Microsoft Q&A Platform. Thank you for reaching out & I hope you are doing well.

I understand that you are facing issues with AFD.

From the error message, it appears one of your backend Origin is in an unhealthy state.

Is this issue still happening?

Can you confirm if the AFD is working fine despite the notification?

Can you directly access the individual backend and see if they are up and running as expected?

You can also check the HealthProbeLogs from AFD and determine why the health probes are reporting failure

Cheers,

Kapil
Patchfox 3,621 Reputation points

2023-02-22T12:24:41.8066667+00:00

Hi,

can you show the configuration of the origins (backend).
Is it possible to manually check the origins for reachability via http/https
Deshmukh, Vijit 496 Reputation points

2023-02-23T05:55:44.64+00:00

Hi @KapilAnanth-MSFT

We are still facing the issue.

Backends source are responding.

Please guide us how and where we can see the HealthProbeLogs.
Deshmukh, Vijit 496 Reputation points

2023-02-23T06:58:11.3633333+00:00

Hi @Patchfox

Please find below screenshot

As highlighted Enable Health probes was enabled earlier.

After getting the message in FD of unavailable backends we disabled it for the testing purpose.

But issue is still present
Deshmukh, Vijit 496 Reputation points

2023-02-23T07:00:59.6566667+00:00

Hi @Patchfox

Please find below the screenshot
Patchfox 3,621 Reputation points

2023-02-23T08:40:29.0166667+00:00

@Deshmukh, Viji thanks for the screenshots. They look fine at first sight.

Is it possible to send us the health probe log (after activation) additionally.
Deshmukh, Vijit 496 Reputation points

2023-02-23T13:12:27.87+00:00

@Patchfox Please let me know how and from where I can extract that log
KapilAnanth-MSFT 35,001 Reputation points Microsoft Employee

2023-02-23T15:33:10.1266667+00:00
@Deshmukh, Vijit

I take it that AFD is working despite the notification - is this correct?

Please refer to the Configure Logs section to enable Logs for AFD.

Also, enable health probes to the Origin.

Post this, you can run the below query

AzureDiagnostics | where Category == "FrontDoorHealthProbeLog"

and see what the response received is

Cheers,

Kapil
KapilAnanth-MSFT 35,001 Reputation points Microsoft Employee

2023-03-01T03:36:33.2666667+00:00

@Deshmukh, Vijit

Could you please provide an update on this post?

Kindly let us know if you were able to configure the logs and check the status?

Thanks,

Kapil
Deshmukh, Vijit 496 Reputation points

2023-03-01T13:06:57.7+00:00

Hi @KapilAnanth-MSFT by Running the below Query AzureDiagnostics | where Category == "FrontDoorHealthProbeLog"

Some logs been generated.

Please let me know next step
KapilAnanth-MSFT 35,001 Reputation points Microsoft Employee

2023-03-02T16:27:31.2766667+00:00

@Deshmukh, Vijit

I believe we will need a specialized 1:1 session, where a support engineer can have a screen share session to pinpoint the issue.

If you have a support plan you may file a support ticket, else please do let us know, we will try and help you get a one-time free technical support.

In case you need a one-time free technical support could you please send an email to azcommunity[At]microsoft[Dot]com with the below details.

Subject : Attn Kaananth | Unavailable backends in azure frontdoor

Thread URL: Link to this thread.

Subscription ID : Subscription ID of the front door

Cheers,

Kapil