Using the Windows Azure Content-Delivery Network (CDN)
The Windows Azure Blob Service is hosted in a small number of Windows Azure datacenters worldwide. The Windows Azure Content-Delivery Network (CDN) is a service that enhances end user experience by caching blobs in more than 20 strategic locations across the World.
After the CDN is enabled for a storage account, a CDN endpoint can be used, instead of the storage-account endpoint, to access a cached version of publicly accessible blobs in the storage account. The CDN endpoint is location aware, and a request to the CDN endpoint is directed automatically to the closest CDN location. If the blob is not currently cached there, then the CDN retrieves the blob from the Blob service endpoint and caches it before satisfying the request.
The cache-control property of the blob can be used to specify a time-to-live in the cache. Otherwise, the CDN uses a heuristic based on how old the blob is and caches the blob, for the shorter of 72 hours or 20...
