Azure Function app is on TLS 1.2 and Service on TLS 1.0 , causing data loss issues

Question

Hello!!

We have been facing few data loss issues in our Prod, my observation is that our function app is running on TLS 1.2 and Service Bus still at 1.0. I have seen notifications/warnings regarding the deprecation on TLS version(1.0, 1.1) from Feb end.
We seeing the issues in our systems from march that the end systems are complaining that they are receiving partial data only(like 130 records sent only 115 received)

I have checked the app insights configured, mostly the issues are with Service Bus processing only , its delaying too much and sometimes like trying to insert duplicate data eventually caught exceptions.

I can upgrade my Sb to 1.2 , but still i am not sure why this issue is happening from March only, is that related to TLS 1.0? and we didn't made any code changes from last one year (in SB or Function app). Why partial records are processing?

Please help and through some light on it.

Regards,

Sujeeth

Answer 1

Hello ,

Welcome to the Q&A platform! Thank you for raising your question.

According to the update, the exact retirement date for TLS 1.0 and TLS 1.1 in Azure services varies by service. For the Azure Service Bus, TLS 1.0 and TLS 1.1 will be deprecated on February 28, 2025.It seems thats why you are getting this error from march. However, several other Azure services will continue supporting TLS 1.0 and TLS 1.1 until August 31, 2025.You can check the link for the retirement dates within the portal. Link

To ensure uninterrupted services, it is highly recommended to upgrade your TLS version to TLS 1.2. If your services are affected, a network trace would show the successful establishment of a TCP connection and successful TLS negotiation before a 401 error is returned if the TLS version used is less than the minimum TLS version configured.

Please accept the answer if you find it helpful. Thank you!

Thanks

Deepanshu