Windows Azure Storage Introduction and Application Scenario selection

Applications cannot be separated from data, and cloud computing applications are supported by data. Windows Azure Service Platform, Microsoft Cloud Computing Services platform provides storage Service--windows Azure storage to store data for cloud applications and, of course, SQL Azure to store relational data. Windows Azure Storage consists of three important parts or three storage data services: Windows Azure Blob, Windows Azure Table, and Windows Azure Queue. This article will give you an overview of the three storage services in Windows Azure Storage, the configuration and use of development storage in the Visual studio environment, and the Windows Azure storage scenario.





the composition of the Windows Azure storage service





Windows Azure Storage consists of three important parts:


Windows Azure Blob: Storing large data.





Windows Azure Table: Stores table data, similar to a datasheet in a relational database, but different, as described in the following article.





Windows Azure Queue: Provides an assignment message service for asynchronous work, somewhat similar to a Windows system message queue.

Their composition can also be described using the diagram:

(1) Windows Azure Blob

The easiest way to use storage services in Windows Azure is to use Windows Azure blobs. BLOBs store binary data, such as images, XML documents, compressed files, and other bytes that are arranged in any container.

BLOB storage data is implemented through a simple hierarchical relationship, with each account having a container, which is a user-defined set of BLOBs (BLOB sets) with only one attribute, and the container does not store data directly, and each blobs contains multiple blobs. The Windows Azure blob stores data and hierarchy relationships as shown in Figure 2:

Blob stores the data by the address:

http://.blob.core.windows.net/

It can be done in rest, that is, by using the access method shown in Figure 1: HTTPS. When uploading large files, we can first split large files into multiple blobs to upload, which solves the problem of large file uploads. The block is transparent to the download process, and the downloader does not have to know how many blocks the file it is downloading is divided into.

Note In the put BLOB operation you can upload the maximum 64MB of data to create a blob, by uploading a contiguous block can create a blob larger than 64MB, the maximum block can only be 4MB.

(2) Windows Azure Table

BLOBs only for large capacity two-tier data storage, it is too "unstructured". In order to save and use dense data in a cloud application, such as storing an object in a cloud storage service, this object is somewhat of its own, and in fact such objects can be considered examples or entities, so Windows Azure table comes in handy. Windows Azure table can store entity classes and entity objects directly into the table structure.

The difference between Windows Azure table and SQL server/sql Azure is that Windows Azure table is a service designed to store data with entity relationships rather than relational databases. Windows Azure Table provides lightweight, fast, low-cost, mass-storage data, including entities and attributes. It is not a relational database, so it cannot provide a method similar to joins in SQL, nor can it manage the foreign keys. In fact, a single Windows Azure table can store billions of entities, and a Windows Azure table can reach trillions of bytes, which is a fairly large amount of storage. This can also be illustrated by example Figure 3.

(3) Windows Azure Queue

Windows Azure blob and Windows Azure table are used to store and access data. Windows Azure provides a third type of storage service Windows Azure Queue, which provides the dispatch messaging service for asynchronous work, and one of the most common applications is the message queues that communicate between the worker role instance and the Web-role instance. For an example of Windows Azure queue usage We will describe it in a scenario.

Regardless of whether a blob, queue, or table is used to store data in Windows Azure Storage, Microsoft Cloud computing Services platform will store blobs in at least three separate containers in the same data center to ensure data security. The location-based features of table and Queue,windows Azure allow you to replicate data to multiple Microsoft Data centers, enhance disaster recovery capabilities, and improve performance in specific areas.

After installing the VS2008 or VS2010, SQL Server 2005/2008/2008 R2, you can then install an extended toolkit for cloud application development, which is: Windows Azure tools for Microsoft Visual Studio 1.1, whose download address is:

http://www.microsoft.com/downloads/details.aspx?familyid= 5664019e-6860-4c33-9843-4eb40b297ab6&displaylang=en

The process of developing cloud applications using VS 2008 and VS2010 is not fundamentally different, but VS 2010 provides the development of cloud applications , debugging, deploying, and managing the entire set of tools, such as developing cloud computing program patterns, developing cloud computing models, project templates for cloud computing, off-line testing of cloud computing projects, cloud computing deployments, and so on, which shorten the development cycle of cloud applications, we will use vs get to develop cloud applications. Note that SQL Server Express needs to be installed during the development of the cloud application, and installation can be added using the VS 2010 installation file If it is not installed.

In addition to the above installation, Windows Azure Storage is used in the Visual studio environment, and the Windows Azure SDK is installed with the download address:

http:// Www.microsoft.com/downloads/details.aspx? familyid=21910585-8693-4185-826e-e658535940aa&displaylang=en

says Windows Azure storage in Visual In the development environment under studio, the following steps are needed to get Windows Azure storage to "Run" in a cloud application:

(1) Configure the connection string: This string indicates your Windows Azure storage account.

(2) initializes Windows Azure Storage: Sets the project's start Development Storage Services property to True by right-clicking the project | Properties, Attributes | Development tab, develop tab| Start Development Storage Services.

Once these installations and configurations are complete, we can access windows by using the Windows Azure Consolidator Library and the Windows Azure Storage Services REST APIs in our programs two class libraries Azure Storage. The Windows Azure Consolidator Library contains the namespaces:

Microsoft.windowsazure Microsoft.WindowsAzure.ServiceRuntime Microsoft.WindowsAzure.Diagnostics Microsoft.WindowsAzure.Diagnostics.Management Microsoft.WindowsAzure.StorageClient Microsoft.WindowsAzure.StorageClient.Protocol

The Windows Azure Storage Services REST API provides a BLOB service API, a Table service API, and a Queue service API.

Windows Azure Storage Application Scenario

In the Windows Azure storage scenario, we'll show you some of the Windows Azure storage scenarios by using some sample diagrams or actual diagrams.

In the scenario shown in Figure 4, the user accesses the data in the table through the Web role instance, and the message passing between the Web role and the worker role is done through the queue, while the worker role accesses the large data in the BLOB.

In the scenario shown in Figure 5, message passing between WEB role and worker role is done through queue, while worker role accesses large data in the BLOB.

In the application scenario shown in Figure 6, the user accesses the data in the table through the Web role instance.

Here are two data interfaces that are accessed using BLOBs and table, as shown in Figure 7~8:

In Figure 7, we can browse to the binary data stored in the BLOBs, the default state, the data is read-only, you can find the data in the above search bar, you can download the file, this is not similar to FTP?

in Figure 8, a table is used to store data, each row is marked with an entity, and each column identifies an attribute of the entity. The storage looks similar to the SQL Server datasheet. Similarly, data can be filtered, and data can be refreshed.

Summary

Windows Azure platform supports three extensible persistent storage: unstructured data (BLOBs), structured data (Table), applications and services, or messages (Queue) between applications and services. Combined with Visual Studio's development environment and application scenarios, the understanding of Windows Azure storage services is deepened.