Determining Azure Blob Storage Access Tiers with Ease

One of the things that is rather powerful about Azure Storage is that there are a number of different offerings. Azure Blob Storage has three tiers that should be very familiar Hot, Cool, and Archive. If you haven’t seen this Microsoft Docs post about the Azure Storage Tiers, I recommend you give this a quick read.

Hot and Cool are rather straightforward in their use case, but Archive is the one I’d like to bring some attention to. Archive is a special use case in Azure in that it has different retrieval costs, different retrieval times and more. I like to explain it as write once, read never, but never say never.

Determine which Azure Blob Access Tier is in Use

Azure Blob Access Tiers are set a number of ways, either how a data blob is made or by being inferred by the folder or container properties at a parent level. One of the easiest ways to set, view and manage Azure Storage outside of the Azure Portal is via the Azure Storage Explorer.  By the way, if you want an insider tip to know what’s coming from this cool tool, subscribe to this GitHub project for updates before the Azure Storage Explorer tool is updated. The figure below is the Azure Storage Explorer:

Image #1 Expand
rv az archivefig1

The most handy part of the Azure Storage Explorer is the Access Tier column, this is very helpful to discern what type of Azure Storage Tier is assigned to a blob, folder or other items.

Configuring Azure Blob Storage Tier in the Azure Portal

While the Azure Storage Explorer is indeed a quick and easy way to do some administrative work with Azure Blob Storage, there is always the Azure Portal. I go back and forth on which is my preferred interface. For provisioning, cleaning up and usage with other services; I like to use the Azure Portal. For specific inquiry, visibility and small scale ingest (or removal) of data; I like to use Azure Storage Explorer. Both have their use cases, both are Microsoft platforms. The only caution is that if you don’t update the Azure Storage Explorer, you may run risks of not being able to interact with the Azure Storage services with very old versions (updates are easy by the way). Nonetheless, in the Azure Portal, you can easily see the Azure Blob Access Tier as well:

Image #2 Expand
rv az archivefig2

Configuring or setting the tier has a special behavior in Azure that I think is unique among the cloud storage industry. The unique aspect is that within a single storage account, blobs sitting in a folder can have all types of explicit tiers (hot, cool, archive).  So, mix and match to your heart’s content! You’ll see applications who are tightly integrated with Azure storage take advantage of this efficiently as well.  So whether you upload data into Azure via the Azure Portal or via Azure Storage Explorer, the access tier can be set easily.

Further, the Blob Access Tier can be inferred. Inferred generally means it will take the property from the storage account settings. See this Petri post on how to configure an Azure Storage account. The storage account can be set to either Hot or Cool, but not Archive (I’ll get to that in a bit). The figure below shows a blob storage resource that is inferred:

Image #3 Expand
rv az archivefig3 1

Azure Blob Storage Access Tier Best Practices

The important thing to remember about the Access Tiers is that they each have their own price and performance characteristics. Archive is the special one, as the retrieval time and costs are unique for the use case and this should not be approached without consideration.

The main catch point for Azure Blob Storage Archive Access Tier is that it is expected to be stored for at least 180 days and the retrieval time (to read that data) can be a high number, measured in hours. Not every use case is suitable for that.

A best practice for Azure Blob Storage Cool Access Tier is to use if you don’t need the higher throughput (especially on egress), you don’t necessarily need to over-provision throughput if you don’t plan on using it. Likewise, if you need the highest performance for a Blob resources; Hot is where to go.

Using Azure Blob Storage Access Tiers

Using Blob storage is an important storage service in Azure, and you’ll be keen to use the right access tier for the right data. You can easily manage Storage Tiers either in the Azure Portal or via Azure Storage Explorer, your choice!