Storage Tiering

Every file in your app goes into Azure Blob Storage in the same tier: Hot. Hot costs more per gigabyte, but it returns a file the fastest, which is great for a file that's actually being read right now.

Most files aren't being read right now. A file nobody's touched in months still sits in Hot storage, costing exactly as much per gigabyte as a file being read constantly. As more files pile up, your storage costs just keep climbing, even though most of that storage barely ever gets touched.

Every file sits in the same expensive tier forever, whether it's read every day or not at all. That's exactly what storage tiering fixes.

Storage tiering moves the quiet files somewhere cheaper, automatically: turn on an Azure Blob Storage lifecycle management policy on the storage account, with a rule that moves a file from Hot to Cool once it hasn't been read for a set number of days, say 30, and a further rule moving it from Cool to Archive after longer, say 180 days. A file can move back to Hot if it suddenly gets read again, at the cost of a slower first read.

Use: Azure Blob Storage Lifecycle Management

Keep only what's actually being read in the expensive tier, and let a policy move the rest down on its own.

A kitchen keeps the pans used every day on an open shelf by the stove, within arm's reach. A roasting tray used once a year for a holiday gets packed away in the attic instead, taking longer to dig out but not taking up counter space the rest of the year.

Keeping the roasting tray on the open shelf all year would mean paying for prime kitchen space with something used once.

Keep what's used constantly within easy reach, and move what isn't into cheaper, slower storage automatically.