Cloud computing is the concept of using the power of large servers for computation, i.e. all computation is on Internet. Cloud computing customers then can use applications, store data, and do various computings via Internet, as a service, and pay for the amount of resources they used.
Microsoft's Windows Azure Platform is a cloud computing platform which provides a wide range of Internet services. In other words, it is a group of cloud technologies. Each of those technologies provides a specific set of services to application developers. This means that developers have an application platform, which provides all needed services for creating applications. Developers have not to invest in buying and maintenance their own machines, because they use infrastructure of the cloud (it is called Infrastructure as a Service). Also, they can use cloud as a data (and/or source code) storage. This means that applications that run inside a company (also called on-premises applications) can store their data in the cloud, or alternatively applications can run in a cloud and store data also in a cloud. The key is that they use services of a cloud, and pay for how much they use. Those services are for example framework, database server etc.
Windows Azure Platform consists of 3 components: Windows Azure, SQL Azure, and AppFabric.
Windows Azure:
Windows Azure is an operating system which provides developing environment, service hosting and service management environment for running applications and storing data at Microsoft data enters. It supports multiple languages and can integrate with on-premises environment. It supports standard protocols and standards, including SOAP, PHP, XML, and REST. Precisely, Windows Azure provides following features:
- Computation Services: Ability to run ASP .NET or .NET code in the cloud, service hosting environment – IIS 7.0, Microsoft .NET Framework 4.0 and Microsoft .NET Framework 3.5 SP1, fast CGI which allows running web applications written with PHP and other non-Microsoft programming languages, .NET Full Trust for usage of additional features as WCF, call into unmanaged DLLs, runtime API for logging and local scratch storage, web portal used for deploying, scaling and upgrading services quickly. Security is supported by Code Access Security policies.
- Data storage: As you compute in cloud, you can store those tables, queues and blobs. Safety of data is improved triple replication and of course authenticated access. Data is accessed through REST interfaces.
- Development Tools: Windows Azure offers complete offline development environment including computation and storage services. Also there are command-line SDK, Visual Studio add-in that enables local debugging. Visual Studio 2008 and Visual Studio 2010 are extended to enable developing process of scalable web applications and services on Windows Azure.
SQL Azure:
SQL Azure provides relational database service based on SQL Server. Following are major features of SQL Azure:
- Relational Database Management Services: Provides creating, accessing and manipulating database objects, Insert, Update and Delete operations, constraints, transactions, temporary tables, functions, some of SQL Server built-in stored procedures and system views. Also it provides support for tracking billable metrics in real time.
- Programmability: there is PHP support, native ODBC and managed ADO .NET access.
- Tools: offers deployment support for running SQL configuration scripts and provision of logical servers and databases.
AppFabric:
Third component, AppFabric, is for connecting applications in the cloud or on-premises. It includes applications running on various platforms – Windows Azure, Windows Server, Java, Ruby, PHP, etc.
It has two big parts – Service Bus and Access Control. Service Bus is bridge between on-premises and off-premises applications. Also it can be used for connection of Windows Azure and SQL Azure databases with other applications and databases and for creating composite applications. Access Control, as its name says is used for various types of authentication and authorization.
Pricing information:
There are several pricing offers. Here will be presented the most interesting one, which is typical for cloud computing. Consumption mode in which you pay how much you use – for example for Windows Azure Compute service at small instance price is $0.12 per hour. Price for Storage service at Windows Azure is $0.15 per month and $0.01 per 10.000 storage transactions.
SQL Azure in Consumption mode has two editions – Web edition, in which $9.99 is per database up to 1GB a month, or $49.95 per database up to 5GB per month. Business Edition is from $99.99 a month, depending on a database size. For AppFabric, Access Control price is $1.99 per 100,000 transactions. Service Bus is being paid for number of connections - $3.99 per connection or in packs of 5, 25, 100 or 500 connections for respectively $9.95, $49.75, $199.00, $995.00.
More pricing offers and detailed pricing information can be found on official site.