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Azure CDN – Solutions for things that are not available (yet)

Last week I had some interesting discussions around payload delivery and CDNs. I realize how easily people can misunderstand some features or functionality, thinking that it is normal or making the wrong assumption.
In this context, I will write 3 posts about Azure CDNs, focusing on what is available, what we can do and what we cannot do.

Let’s see what we can when we need to do when we need the Azure CDN features that are missing in this moment in time. In the last post we talked about this features, we will not focus on explaining them – for this please see the previous post.

SAS Support for Blob Storage
If you need on top of Azure Store, a CDN system that has support for SAS, then you need to be inventive. The simplest solution is to replicate the content in multiple Azure Storage Accounts or even in the same Storage Account (if the problem is download speed) and create a web endpoint (that can be hosted as a web app), that will provide the locations from where the content can be downloaded.
This web endpoint, can have a Round Robin mechanism (the simplest thing) to serve different locations.

Using this approach, you will also need a mechanism that replicates the content in multiple locations. AzCopy might be a good out of the box solution.

HTTPS for Custom DNS Domains
The same store with Azure CDN is with Azure Storage. In this moment we don’t have yet support for HTTPS and Custom DNS Domains. In this case if you really need HTTPS, then the only solution is to serve the content from an Azure Web App. There not to many options for now.

HTTPS Client Certificates
The story is similar with the previous one. We don’t have to many options. The best way for now is to use an Azure Web App and serve your binary content from there.

None. As above an Azure Web App.

Fallback to custom URI
For this situations, we have a simple solution. We can go with the approach presented in the SAS Support example. The additional thing that we need to do is to have multiple Azure Web Apps that can server the content location and add an Azure Traffic Manager in front of them.

Access logs of CDNs are raw data
If you really need this logs, then you need to use Azure Blob Storage. The above approach and activate logs in each Azure Storage Account.

As we can see, there are so many features support by Azure CDN. Of course we will not be able to find a perfect solution that supports all the things that we need. The same is happening with Azure CDN. But what is important to remember that a part of the features that we are missing are already marked as In Progress in the feedback portal of Azure. This means that soon, we will have support for them also.


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