Microsoft released Windows Azure as a production service in February 2010. A common complaint was that it was too expensive to develop small websites because a web role could support only a single website. The cause of this limitation was that a web role hosted a website using hosted web core rather than full IIS.
With the Windows Azure SDK v1.3 release, Windows Azure added support for full IIS for web roles. This means that a single web role can host multiple websites. However, all of these websites share the same Virtual IP (VIP) address, and a CNAME record must be used to map the domain name of the website to the servicename.cloudapp.net URL for the web role. Each website is then distinguished inside IIS by its distinct host header. The Providing a custom domain name for a hosted service recipe in this chapter shows how to use a CNAME record to map a custom domain to a hosted service domain. Note that full IIS is also available on worker roles.
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