Practicing Microsoft Azure: Part 6 (Cloud Computing)

1.1.4 CDN

A Content Delivery Network (CDN) avoids user latency problems by reducing the number of hops the request must make. This service provides a convenient way to minimize latency, because it caches data in various geographic locations across the globe. At a site, the Content Delivery Network (CDN) stores replicas of a BLOB closer to the clients that use it. Blobs typically store information such as videos that will be accessed from many locations. Hence, this mechanism speeds up the delivery of reputedly accessed content and improves performance.

1.2 AppFabric

Azure AppFabric provides a wide-ranging cloud middleware platform for developing, deploying and managing applications on the Windows Azure Platform. It allows the creation of combined access control and distributed messaging across clouds and enterprises and enables the linking of our existing applications to the cloud using secure connectivity across networks and geographic boundaries. Developers practice Windows Azure AppFabric to connect application pieces together, manage identity and access control, cache remote resources and create composite applications. Developers can build WCF-like services in Visual Studio .NET and publish endpoints to the cloud from within Visual Studio .NET design environment. The following diagram depicting the diverse components of AppFabric as in the following:



1.2.1 Access Control

The Access Control mechanism in the cloud employed to identity and access control to web applications and services resources using REST and the Web Resources Access Protocol (WRAP), while integrating with standards-based identity providers, including enterprise directories such as Active Directory (AD) and other web identities including Windows Live ID and Google. The client sends the request or claims to the public Access Control URL to access a specific remote application resource. Further, the Access Control service checks the input claims against the defined rules and produce the output claims and sends these claims in a secure token that the client application then sends to the remote application.



1.2.2 Caching

Caching is the most effective ways to improve performance to frequently accessed data in ASP.NET websites. Some applications repeatedly accesses the same information, caching therefore and making this information more readily accessible can make the application faster. In final words, the caching provisions in-memory, distributed and highly available application cache services for Windows Azure applications.



1.2.3 Service Bus

Via HTTP and the REST protocol, the Service Bus service allows secure connectivity and messaging experiences through which distributed applications can talk together. The Service Bus is of course, hosted in the cloud atmosphere, so any application with an internet connection can access it. You create a new service namespace using the portal itself to start exchanging messages via the Service Bus from any application and platform. The messages transmitted by service bus contains XML, graphics, binary data, text and streaming data content and moreover exposes classes to various programming environments using REST and HTTP to interact with the Service Bus nodes.

1.3 SQL Azure

The SQL Azure technology is employed into the cloud atmosphere to address the growing size and scale of the data that can address the primary data challenges associated with scalability, availability, security and manageability. Developers can access SQL Azure using a tabular data stream typical accessing on-premise SQL Server instances using SQL clients like ADO.NET, ADO.NET Entity Framework, LINQ and ODBC. Developers can create tables, indexes and views, use Stored Procedures and define triggers alike with SQL Server. Moreover, the significant benefits for SQL Azure is that the management requirements are significantly reduced because they need not worry about other operations, such as monitoring disk usage and servicing log files. The following figure depicts the various components of SQL Azure as in the following:



SQL Azure is the cloud-based technology solution to deal with relational and other types of data as part of the Windows Azure platform. Broadly, SQL Azure provides the following activities and key benefits:

• SQL Azure offers “Server Management Studio” that is an integrated environment to configure and access the databases on the cloud.
  
  
• SQL Azure provides a similar authentication and authorization framework as that of SQL Server databases in on-premise systems and using firewall security that can be configured using Azure Management Portal.
  
  
• SQL Azure supports overall development, deployment and provisioning of databases on the cloud.
  
  
• SQL Azure performs basic operations, including Create, tables, indexes, views, roles, Stored Procedures, triggers and functions, Constraints and Temp tables.
  
  
• SQL Azure executes complex queries and joins across multiple tables, as well as performs transactions with basic aggregation functions.
  
  
• SQL Azure performs the logging and monitoring of administration capabilities to monitor and track the potential issues associated with the data.

1.3.1 Database

A SQL Azure Database provides the core database functions of SQL Server as a cloud service. An application using SQL Azure Database typically accesses data via a protocol called a Tabular Data Stream (TDS) that is also used to access a local SQL Server database. So, a SQL Azure Database application can use any existing SQL Server client including ADO.NET, ODBC, Entity Framework, PHP and others.



1.3.2 Reporting

The SQL Azure Reporting is based on SQL Server Reporting Services used to meet the demand for reporting of stored data in a SQL Azure Database. Such created reports can be published to a SQL Azure Reporting portal and accessible to a user via an URL. Reports used with SQL Azure Reporting are created on-premises and designed to correlate with data stored in a SQL Azure Database.

1.3.3 Synchronization

The key feature SQL Azure is to offer anytime and anywhere access of data by means of SOAP and REST interfaces. Further, you can use the SQL Azure by creating a storage account in the Windows Azure platform account. Hence, Azure Data Sync enables an equilibrium between SQL Azure and on-premise SQL Server for the purose of providing bidirectional data synchronization functionality based on the Microsoft Sync Framework and allows linking an on-premise database to a SQL Azure Database. Each Windows Azure platform account can host several SQL Azure storage servers that can include multiple databases that use the Master database by default.

1.4 Marketplace

The Windows Azure marketplace contains data and various other application market segments including data and web services from leading commercial data providers and authoritative public data sources. Customers will have access to datasets such as demographic, environmental, financial, retail, weather and sports. The following figure depicts the various components of the Azure marketplace.

1.4.1 App Market

The App Market exposes the applications or services created by developers for potential customers so that they can easily use them to suit their needs.



1.4.2 Data Market

Data Market offers a chance to expose their offerings to more customers using Microsoft's cloud platform. In simple words, Data Market provides a single place to find, buy and access a variety of commercial datasets.

Operating in Azure

The initial moment for Azure application development to the cloud is the Windows Azure Development portal that required a Windows Live ID to be access using a remote login utility such as Putty or RDP (mstsc.exe). The typical developer workflow involves the following procedure for creating or deploying an application in Windows Azure Platform.

Step 1: Create a Windows Azure account and login using Microsoft Live ID.

Step 2: Prepare the development fabric to create an application in the local cloud platform.

Step 3: Test the application in the development fabric.

Step 4: Package the application for cloud deployment.

Step 5: Test the application on Windows Azure in the cloud.

Step 6: Deploy the application in the production farm.



Microsoft is currently offering a free one month trial experience of Azure services. However, Microsoft doesn't offer free use of Azure services so far. Even as you create an account after buying the necessary Azure cloud services subscription and finally login into your Azure portal (manage.microsoftazure.com), you will be able to utilize the entire services including, Compute, Websites, Mobile and Data services, offered by Azure virtual operating system.



3. Security Concerns

The Windows Azure platform offers developers with on-demand compute and storage to host, scale and manage web applications on the cloud using Microsoft datacenters. Everything is managed so easily in the cloud; we don't need any hardware, software and configuration at all. But, the sole concern is data or resource security that is a nonnegotiable obligation for a cloud service. Business or sensitive data stored in the cloud needs to be encrypted not only during storage but also transport. Hence, it is mandatory to implement proper access control mechanisms to prohibit unauthorized access to the data and applications because critical data is one step away from getting in malicious hands. Secure channels across application domains in the cloud should be constructed into the cloud service infrastructure. If the environment and applications are not properly secured, any cloud platform could be compromised. However, IT architects are repeatedly concerned about the risks of cloud computing.

Conclusions

Cloud computing is the next generation of emerging technology where everything will be located in the cloud, just a naive device like tablet PC and mobile phone is equipped with an internet connection and a simple browser would be sufficient to get the taste of cloud computing. Executing applications in Azure clouds offer many advantages over the traditional way of running programs, like faster service deployment and massive savings upfront and easily manage business growth by scaling up or down the computing power and storage. Hence, this article provides a comprehensive tour of Windows Azure cloud computing. Moreover it has explained the various layers of the Windows Azure platform, including Windows Azure, data services, AppFabric and the marketplace. Finally, it discusses the life cycle of application development with real experiences of the Azure portal and examines various potential threats when operating in an Azure cloud environment in terms of sensitive data protection and authentication.

References

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• A. Weiss. Computing in the clouds. netWorker, 11(4):16–25, 2007.
• The cloud for modern business.
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• Services that matter and power you can depend on.