Outbound requests from Azure Function "Faulted"

Question

Outbound requests from Azure Function "Faulted"

Mikael Nilsson 5

Hi,

Starting from midnight between 2025-09-03 and 2025-09-04, outgoing requests from our Azure functions have been reporting resultCode "Faulted" with exceptions like these "System.Net.Http.HttpRequestException: Resource temporarily unavailable (oauth2.googleapis.com:443) ---> System.Net.Sockets.SocketException (11): Resource temporarily unavailable"

The http requests useally returns after 10s, hinting about some kind of timeout. It's not only oauth2.googleapis.com, our own azure hosted domains are also effected together with graph.microsoft.com and many others.

We've seen that "System" updated our appservices and functions around the same time that the problem occured (~2025-09-04 00:00 UTC) adding "RouteGeoCapacityClientTrafficToV2" and "RouteOperationClientTrafficToV2" to the "inFlightFeatures" array.

Användarens bild

(timezone in the above image is in CEST, UTC+2)

Användarens bild

Praveen Kumar Gudipudi 1,495 Reputation points Microsoft External Staff Moderator

2025-09-05T10:13:41.4366667+00:00

Mikael Nilsson,

Could you please check the private message and provide the required details for troubleshooting the issue further.

Here is the reference link on how to access & data retention policy of private messages in Microsoft Q&A.
Praveen Kumar Gudipudi 1,495 Reputation points Microsoft External Staff Moderator

2025-09-17T15:57:51.5233333+00:00

Mikael Nilsson,,

Sorry for the delay,

Since the error is "temporarily unavailable," implement retry logic with exponential backoff in your HTTP client code to handle transient network errors gracefully.

Also, please share me the function app plan and current status of the function app.
Praveen Kumar Gudipudi 1,495 Reputation points Microsoft External Staff Moderator

2025-09-22T15:14:51.2466667+00:00

Mikael Nilsson,

We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution please do share that same with the community as it can be helpful to others. Otherwise, will respond with more details and we will try to help.
Praveen Kumar Gudipudi 1,495 Reputation points Microsoft External Staff Moderator

2025-09-24T12:47:30.15+00:00

Mikael Nilsson,

We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution please do share that same with the community as it can be helpful to others. Otherwise, will respond with more details and we will try to help.
Mikael Nilsson 5 Reputation points

2025-09-24T13:24:04.7533333+00:00

Hello Praveen Kumar Gudipudi!

I'm still waiting on an answer from santoshkc who wrote to me in private message. He was going to "check the logs from the backend" on our function.

We've had some progress in this issue with the help of Azure Support, but we've not found out what caused it, starting from the 4th of September. We've checked our own data exensively and nothing has changed from our end. For us the only possible conclusion is that something has changed with the consumption and flex consumption plans.

The issue for us is SNAT Port Exhaustion. We've seen improvements after making sure that we're using .NETs IHttpClientFactory everywhere, but we were still having some issues until we migrated from flex consumption to an app service plan. We believe that this is load-related and not something we can change without impacting our customers.

We've reached the conclusion that this change is permanent and that the consumption and flex consumption in its standard form does not fit our use case any longer.

Our next step is most likely to explore the option of using a NAT Gateway.

Regards,

Mikael Nilsson
Praveen Kumar Gudipudi 1,495 Reputation points Microsoft External Staff Moderator

2025-09-29T12:42:44.8733333+00:00

Hello Mikael Nilsson,

Sure, i will check the logs and share you the root cause.
Praveen Kumar Gudipudi 1,495 Reputation points Microsoft External Staff Moderator

2025-10-06T12:27:23.45+00:00

Mikael Nilsson,

Could you please check the private message and provide the required details for troubleshooting the issue further.

Here is the reference link on how to access & data retention policy of private messages in Microsoft Q&A.

1 answer

Your answer

Praveen Kumar Gudipudi 1,495 Reputation points Microsoft External Staff Moderator

2025-09-05T10:13:41.4366667+00:00

Mikael Nilsson,

Could you please check the private message and provide the required details for troubleshooting the issue further.

Here is the reference link on how to access & data retention policy of private messages in Microsoft Q&A.
Praveen Kumar Gudipudi 1,495 Reputation points Microsoft External Staff Moderator

2025-09-17T15:57:51.5233333+00:00

Mikael Nilsson,,

Sorry for the delay,

Since the error is "temporarily unavailable," implement retry logic with exponential backoff in your HTTP client code to handle transient network errors gracefully.

Also, please share me the function app plan and current status of the function app.
Praveen Kumar Gudipudi 1,495 Reputation points Microsoft External Staff Moderator

2025-09-22T15:14:51.2466667+00:00

Mikael Nilsson,

We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution please do share that same with the community as it can be helpful to others. Otherwise, will respond with more details and we will try to help.
Praveen Kumar Gudipudi 1,495 Reputation points Microsoft External Staff Moderator

2025-09-24T12:47:30.15+00:00

Mikael Nilsson,

We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution please do share that same with the community as it can be helpful to others. Otherwise, will respond with more details and we will try to help.
Mikael Nilsson 5 Reputation points

2025-09-24T13:24:04.7533333+00:00

Hello Praveen Kumar Gudipudi!

I'm still waiting on an answer from santoshkc who wrote to me in private message. He was going to "check the logs from the backend" on our function.

We've had some progress in this issue with the help of Azure Support, but we've not found out what caused it, starting from the 4th of September. We've checked our own data exensively and nothing has changed from our end. For us the only possible conclusion is that something has changed with the consumption and flex consumption plans.

The issue for us is SNAT Port Exhaustion. We've seen improvements after making sure that we're using .NETs IHttpClientFactory everywhere, but we were still having some issues until we migrated from flex consumption to an app service plan. We believe that this is load-related and not something we can change without impacting our customers.

We've reached the conclusion that this change is permanent and that the consumption and flex consumption in its standard form does not fit our use case any longer.

Our next step is most likely to explore the option of using a NAT Gateway.

Regards,

Mikael Nilsson
Praveen Kumar Gudipudi 1,495 Reputation points Microsoft External Staff Moderator

2025-09-29T12:42:44.8733333+00:00

Hello Mikael Nilsson,

Sure, i will check the logs and share you the root cause.
Praveen Kumar Gudipudi 1,495 Reputation points Microsoft External Staff Moderator

2025-10-06T12:27:23.45+00:00

Mikael Nilsson,

Could you please check the private message and provide the required details for troubleshooting the issue further.

Here is the reference link on how to access & data retention policy of private messages in Microsoft Q&A.

Answer 1

We've had some progress in this issue with the help of Azure Support, but we've not found out what caused it, starting from the 4th of September. We've checked our own data exensively and nothing has changed from our end. For us the only possible conclusion is that something has changed with the consumption and flex consumption plans.

The issue for us is SNAT Port Exhaustion. We've seen improvements after making sure that we're using .NETs IHttpClientFactory everywhere, but we were still having some issues until we migrated from flex consumption to an app service plan. We believe that this is load-related and not something we can change without impacting our customers.

We've reached the conclusion that this change is permanent and that the consumption and flex consumption in its standard form does not fit our use case any longer.

Our next step is to explore the option of using a NAT Gateway.

Praveen Kumar Gudipudi 1,495 Reputation points Microsoft External Staff Moderator

2025-10-07T20:22:32.59+00:00

Mikael Nilsson,

Thanks for the update.

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Outbound requests from Azure Function "Faulted"

1 answer

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