What is Windows azure?
Since the launch of the Microsoft PDC Conference in 2008, the windowsazure platform has undergone several changes in functions and modules until the beginning of 2010. As mentioned above, the Windows azure platform currently has four features: Windows Azure, SQL Azure, Windows azure appfabric, and Windows azure connect.
Windowsazure
Windows azure provides distributed and Scalable Computing and storage functions. The so-called computing means windowsazure is responsible for providing corresponding virtual machines and boarding services for the programs deployed on it, including ASP. the net website and the WCF Service provide the IIS-based boarding service. For common background programs (C # Or F #), the host service is provided based on Windows azure worker role, and provides FastCGI-based boarding services for PHP and other applications.
While providing computing power, windowsazure also provides storage capabilities. Unlike sqlazure introduced later in this book, Windows azure provides the following storage services:
Table Storage: A non-relational service that stores structured databases.
Blob storage: a service that stores binary files.
Queue storage: a persistent Distributed Queue Service.
In the windowsazure data center, the computing and storage nodes are responsible for the computing and storage services of Windows Azure, as shown in 2-1. The top Microsoft Online Services Portal is responsible for purchasing and subscribing windows azure. The windowsazure developer portal provides users with the function of controlling windows azure services, including creating and deleting windows azure computing and storage services, managing passwords, and certificates. Both of the above two portals use a Service Management
Services, while providing restapi external interfaces, the underlying windows azure fabric controller of the data center controls its Internal Computing and storage nodes. For storage services, the Windows azure platform also provides a set of rest APIs to facilitate external access.
The application is first developed on the developer's computer through Visual Studio and Windows azure SDK, and then through the developer portal website or Visual Studio (based on the Management Service API ), upload a configuration file to the specified data center. The data center assigns one or more virtual machines according to the configuration file, and then installs the corresponding components by the specific Startup Program. Finally, the application code will be deployed in a specific directory of the virtual machine.
However, applications are not directly exposed to the Internet. The Windows azure platform also supports Server Load balancer while providing computing functions. 2-2 shows the computing service deployed on the Windows azure platform, whether it is an IIS-based website or WCF Service, an asynchronous task executed in the background, and a deployed storage service, when the caller accesses the server over the external internet, the Windows azure platform provides Server Load balancer. In addition, Server Load balancer on Windows azure uses a polling-based scheduling solution. For example, if a user sets up three running instances for a website deployed on the Windows azure platform, that is, there are three virtual machines running website code simultaneously on the platform, when the user accesses this website, the system cannot predict the program on which the current request will access. In addition, when a user accesses a website, each HTTP
Requests cannot always point to the same windows azure virtual machine.
This feature of Windows azure directly affects how developers design applications.
This article is excerpted from the book "Practical windows azure: Microsoft cloud computing platform technology details"
Book details: http://blog.csdn.net/broadview2006/article/details/6859004