BlobContainerClient.CreateIfNotExistsAsync throws exception if container exists

Library name and version

Azure.Storage.Blobs, Version=12.10.0.0

Describe the bug

We are seeing the below error when using Container.CreateIfNotExistsAsync. Please note that the issue is intermittent.

Azure.RequestFailedException: The specified container already exists.
RequestId:8798dabf-201e-0060-0a49-60afb2000000
Time:2022-05-05T06:26:54.0405240Z
Status: 409 (The specified container already exists.)
ErrorCode: ContainerAlreadyExists

Please note that the container is never getting deleted.

Expected behavior

The Exception should not be thrown

Actual behavior

The described exception is thrown.

Reproduction Steps

Use BlobContainerClient.CreateIfNotExistsAsync, we can see the exception in some cases.

Environment

Azure App Service .Net core 3.1

[LenaVinogradov]

We are affected by the same issue. The fact that exception is thrown when container exists and logged to AppInsights enquire extra cost on our AppInsights instances. This is internal exception and should not be logged to appInsights. Suggested workaround of suppressing all 409 is not acceptable as it hides all of them leading to missing critical information for other cases when 409 is not a results of Blob.CreateIfNotExist.

@RakeshMohanMSFT , many people on this thread clearly consider it as a bug. What’s required in order for the product team to treat is as a bug?

[Sandeep7OnShell]

Hi @RakeshMohanMSFT By design everything is alright. The issue is when using BlobContainerClient.CreateIfNotExists, it says “Azure.RequestFailedException: The specified container already exists.” whereas it should just be silent and shouldn’t touch the container when it’s already there.

Note: 409 is not fatal, its just an information/indicator - Application insights flags this as an error/failure. Also, further process seems to be in problem when this happens.