Introduction to Windows Azure Content IBuySpy Receptacle

As part of the Windows Azure CTP, we have released the Windows Azure content IBuySpy Receptacle (CDN), which can be used to transfer Windows Azure Blob content. Windows Azure CDN provides developers with a global solution for delivering high-bandwidth content.

Windows Azure CDN is located in 18 locations worldwide (USA, Europe, Asia, Australia and South America) and will continue to expand. Windows Azure CDN Caches your Windows Azure blobs in one of the best locations, providing the maximum bandwidth to transfer your content to your users. You can open CDN Transport for any one of your storage accounts through the Windows Azure Developer Portal. The CDN provides only the Edge transport of a blob stored in a public blob container that can be accessed anonymously.

The benefits of CDN are the better performance and user experience for those who are farther away from content sources stored in Windows Azure BLOB services. In addition, Windows Azure CDN provides a worldwide range of High-bandwidth access to popular event content.

When you open CDN access for your storage account, Windows Azure Portal provides you with a domain name in the following format: http://<guid>.vo.msecnd.net/. This domain name can be used to access a blob within a public container. For example, for a public container "images" and a storage Account "Cohowinery", once the CDN access function is enabled by the storage account, the user can access the BLOB in the container through any of the following URLs:

Windows Azure Blob service url:http://cohowinery.blob.core.windows.net/images/windows Azure CDN Url:http://&lt;guid &gt;.vo.msecnd.net/images/

When a request is sent through the Windows Azure Blob service URL, the Blob is read directly from the Windows Azure blob service. When a request is sent through a Windows Azure CDN URL, the request is redirected to the CDN endpoint closest to the location where the request was issued. If the desired blob is not found at the endpoint, then the CDN retrieves the desired blob from the Windows Azure BLOB service, caches it at that endpoint, and sets a lifetime (Time-to-live, TTL) for the cache blob. The TTL specifies when the Windows Azure BLOB service should be cached in the CDN before it refreshes the blob. The CDN attempts to refresh the blob obtained from the Windows Azure blob service only when the TTL expires. The default TTL time is 72 hours. At the 2009 PDC conference, we will allow users to specify the standard HTTP Cache-control headers for your Windows Azure blobs. If the value is set for a blob, the TTL is set to the value specified by the Cache-control header.

Caching a blob in a CDN makes sense only if the content is transmitted through the CDN edge cache, so content that is requested only once in the BLOB lifetime does not gain performance gains from the edge cache. The most improved performance is the Blob content that is frequently accessed during its lifetime.

You can also register a custom domain name for Windows Azure CDN Access in the Windows Azure Developer Portal, according to your storage account. For example, if you wish to visit your CDN content via "merlot.cohowinery.com", you can register a custom domain name for the CDN endpoint within the portal. This allows you to access the following 3 URL types:

http://cohowinery.blob.core.windows.net/images/http://&lt;guid&gt;.vo.msecnd.net/images/http:// Merlot.cohowinery.com/images/

The last 2 URLs access the BLOBs in the "Images" container through windows Azure CDN. The first URL accesses the Blob directly through the Windows Azure Blob service.

Use the following steps to open the CDN access function for the storage account:

Access windows Azure Developer Portal. Click your storage account. Click Enable CDN for your storage account. Windows Azure Developer Portal provides CDN domain names in the following format: http://&lt;guid&gt;.vo.msecnd.net/.

The configuration created for the endpoint does not take effect immediately; it takes up to 60 minutes to transfer the registration configuration to a worldwide CDN network. Using the CDN domain name immediately at this time will get a 400 error until the configuration is updated globally.

After you complete the above steps, you must specify which containers are to be used as public containers. (http://msdn.microsoft.com/en-us/library/dd179391.aspx). You can then access the blobs in those containers through the CDN URL. The CDN domain name represents the storage account, so any blob container that is exposed in the storage account can be accessed through the CDN URL.

You can also register a custom domain name for the Windows Azure CDN endpoint. Register with the following steps and use a custom storage domain name for your CDN content:

Access Windows Azure Developer Portal Click your storage account at your http://&lt;guid&gt;.vo.msecnd.net/endpoint click "Manage" to enter your custom domain name in order to complete the registration of the custom domain name , verify that you have the domain name. You will be asked to register a CNAME record for your "Custom.domain.name" (from "&lt;guid&gt;.custom.domain.name" to " Domainnameverification.windows.azure.com, &lt;guid&gt; is specified by the Windows Azure Developer portal. Once you have registered the CNAME, click Verify the CDN endpoint. Windows Azure verifies that the CNAME record exists, and if successful, your custom domain name registration is complete.

Use a custom domain name:

Create a CNAME record that points "custom.domain.name" to "&lt;guid&gt;.vo.msecnd.net" using the following BLOB API to make the container that you want to provide anonymous access into a public container:

After
http://msdn.microsoft.com/en-us/library/dd179391.aspx, you can provide anonymous access to your blob via http://custom.domain.name/.

If you no longer want to cache blobs in a CDN, you can:

deletes a blob from a public container. Use the Blob API to change a public container into a private container:


http://msdn.microsoft.com/en-us/library/dd179391.aspx in Windows Azure Developer Portal, remove Windows Azure from your storage account CDN Endpoint.

BLOBs already cached in the Cdn are preserved until the TTL expires. When the TTL expires, Windows Azure CDN verifies that the CDN endpoint is still valid and that the Windows Azure blob can still be accessed anonymously. If not, the BLOB is no longer cached. This means that if you change the contents of the Blob and the Blob is cached in the CDN, these new changes will not be fed back through the CDN until the lifetime of the cached content expires and the CDN refreshes its contents.

Additional Information:

Now CDN access to your BLOB will not be charged. We will provide Windows Azure CDN Solution Pricing information in the future. To achieve the best performance, we recommend that the cached blob be less than ten GB. Windows Azure CDN Access only supports anonymous access. CDN Access does not support HTTP. HTTPS. A custom domain name can only be registered for one storage account endpoint at a time. For example, you cannot register "merlot.cohowinery.com" with 2 different Windows Azure CDN endpoints at the same time. You can register overlapping domain names for different endpoints. For example, the following domain name can be registered for different storage accounts or endpoints at the same time. : http://merlot.cohowinery.com/http://vintage.merlot.cohowinery.com/