ASP.NET Azure Blob Geographically Redundant Storage - How to use?

Question

I have been searching for an answer on MS, SE and Google and cannot find it. I want to use the GRS option for Azure Storage (Cloud Block Blobs) but I cannot figure out how to properly do that.

I created my storage object in Azure and chose the GRS option.

I get that I have a primary and secondary connection string and know how to get that from the Azure portal.

What I do not know, in ASP.NET 4.0, is how to set both connection strings in the CloudBlockClient and gracefully handle the primary storage being unavailable. --What exception is thrown and where, when primary is unavailable? Is this thrown when I create the client, or when I try to get a blob reference? -- How do I then use the secondary?

Do I have to just test for any old exception and then try using the secondary connection string in a new CloudBlockClient if the primary does not work? Or is there anything in the API for this. I would think there would be but I cannot find it.

None of the "How to use Azure Storage" tutorials I have seen go into this. Most of the documentation seems to date from before mid-2014 when this feature became generally available.

Answer 1

This blog post should help you. In short if you want to read from both primary and secondary you want to enable RA-GRS - essentially read access from the secondary. If you are using out storage client libraries you can also enable a retry policy that will first try to read from a primary and then from the secondary if the first read fails.