Feature Request: Azure Container Storage support

[takekazuomi]

Is the feature request related to the problem? Please explain.

Azure Container Storage support.

https://azure.microsoft.com/en-us/blog/embrace-the-future-of-container-native-storage-with-azure-container-storage/

Currently, when we try to host stateful services, the storage performance is insufficient.

Please explain your desired solution.

For example, the current Azure Storage File does not have enough performance to host kafka, mysql, etc. It cannot be used in production due to scalability issues.

Please explain the alternatives you considered.

We considered Azure Storage File, but the results were disappointing.

[simonjj]

Thank you for raising this with us. Could you maybe share some of the performance numbers you've seen please?

[kazeno]

I think anyone that has dealt with systems requiring reading and writing thousands of small files has seen the severely lacking performance of ACA in this regard. Even the internal container storage is at least 2x slower than on comparable Azure VMs, but taking that internal container storage as a baseline, and based on my experience on file-heavy PHP frameworks:

• Shared storage (between replicas in a revision) is at least 2x slower than internal storage
• Azure Premium Files is at least 6x slower than internal storage (and that's the high performance tier)

Definitely the storage options, and especially their performance, are one of the most severe weak spots in ACA, and since it's directly based on Kubernetes, I think adding Azure Container Storage is a no-brainer, as adding better storage options should be a top priority in order to expand possible use cases of the platform.

[DavidMarquezF]

Another issue that you come to (and not documented really) is that files loose permissions and owners, (unlike something like Azure Disks, which are used in AKS). Not having other storage options available makes it very hard/nearly impossible to migrate my workload form AKS to ACA (see #1135 )