Windows Azure Storage blob storage mechanism overview

Windows Azure provides a highly scalable storage mechanism for storing structured and unstructured data, known as Windows Azure Storage. Windows Azure Storage provides a development interface for the REST-based Web Service. This means that any programming language under any platform can access Windows Azure Storage by this development interface as long as it supports HTTP communication protocols. Of course, Windows Azure applications that are in the same datacenter are more likely to be able to access Windows Azure Storage performance.

Like Windows Azure Cloud Services (hosted service), Windows Azure Storage provides the fault tolerance required to maintain high availability, all currently stored in Windows Azure Storage data Microsoft automatically backs up three copies to prevent loss of data, and Windows Azure Storage also provides data backup services that automatically cross data centers if users are willing to pay additional costs.

Because the data stored by Windows Azure Storage is accessed through the HTTP communication protocol in a rest architecture, many function libraries that support the rest architecture in the. NET framework can use Windows Azure at different levels of abstraction Storage. For example, a developer who is familiar with the. NET Framework can directly use WCF to call the Windows Azure Storage API, or access Windows Azure Storage via the WebRequest category directly from the HTTP communication protocol, while The Windows Azure SDK also provides a properly encapsulated client library for the. NET Framework, making it easier for familiar. NET Framework developers to use Windows Azure Storage. Because Windows Azure Storage uses a rest architecture, other non-Microsoft programming languages and software frameworks, such as Java, PHP, and Ruby, can be easily integrated. Currently, Windows Azure Storage provides four types of storage mechanisms, blobs, drives, tables, and queues respectively. Before using Windows Azure storage This service, users must first establish a properly stored account (storage accounts) through the Windows Azure Management portal site https://manage.windowsazure.com/.

While establishing a storage account, the user must determine the location of the data center where Windows Azure Storage resides, and for Taiwanese users, it is recommended that the Microsoft East Asia Data Center be used to obtain a better access rate. At present, each storage account allows storage of up to terabytes of data, users can set up five accounts by default, if users need to expand the higher than the default value of storage, you can contact Microsoft Online Support Request assistance for the purpose of achieving the amplification.

Blobs

In general, BLOBs are storage mechanisms designed to store large binary data, the so-called binary data contains images, films, music and other types of files, each storage account can have any number of containers (containers), and each container can be stored in any number of binary type data, Any program or browser can access a specific binary file by storing the URL of the account and the container in the context of permission control allowing access, and the format is as follows

HTTP (s)://< Store account name storage accounts name>.blob.core.windows.net/< container name container name>/< binary data file name blob Name>

The Windows Azure blob storage mechanism also supports the concept of root container (root container), which works when the binary file I store only wants to be expressed in domain name, and users only need to use reserved names $root can represent the root container. Suppose that an image file named "mypicture.jpg" is stored in a BLOB and the user registers a stored account as "MyAccount", and the user expresses the URL of the file in the following manner:

http://myaccount.blob.core.windows.net/$root/mypicture.jpg

Will equate to this URL as follows:

Http://myaccount.blob.core.windows.net/mypicture.jpg

Users are free to organize the hierarchy of many files stored in a BLOB with the namespace (namespace) (hierarchical), but in most applications, namespaces are often simple without too complex hierarchical relationships. An example of a BLOB namespace is as follows:

Http://myaccount.blob.core.windows.net/pictures/trips/seattle/spaceneedle.jpg

At first glance you might think that there are multiple tree-level folders "Pictures", "trips" and "Seattle" that correspond to the namespace of this blob, but in fact many of the members in all the paths are only the names of the binary files themselves. In this example, the name of the container (container) is "pictures" and the stored binary file name is "Trips/seattle/spaceneedle.jpg".

Containers (container) and binary files are free to choose whether or not to store additional metadata, which are composed of a string pairing name (name)/value (value) that can store up to 8 kilobytes (KB) of information. In addition, developers can add, move, and delete data from Windows Azure blobs through Create, Update, and Delete methods. BLOBs also provide advanced data manipulation commands such as Copy, Snapshot, and Lease.

In Windows Azure blobs the container (container) is also the basic unit of permission control, and all applications that access blobs by default need to know a set of security key values (secret key), and developers can set access rules in a container for the unit. Of course, users can also open Windows Azure blobs to anyone anonymously to access binary files through this mechanism. In addition to container-level permission control, Windows Azure BLOB also provides permission management at the binary file level, and access control at the container level will affect whether a program can successfully locate and access all binary files within the container. However, the management of the binary file level will further determine whether the URI of the specific file (Uniform Resource Identifier) can be accessed smoothly by a program. The following figure is the user interface for the Management container (container) in the Windows Azure Management portal site.

Windows Azure provides CDN (content IBuySpy Receptacle) cache, all data placed in Windows Azure BLOBs can be combined with CDN services to quickly take your data to the nearest data center from your customer's location. Increase the speed at which users access binary files. For example, a large film file is particularly popular in Taiwan, where users can store the video files in a windowsazure blob and enable CDN services, allowing users in Taiwan to visit faster, and Windows Azure is a handful of cloud services with CDN data centers in Taiwan, This service will dramatically increase the binary file access rate, and will add additional costs to Microsoft.

The following illustration shows how Windows Azure blobs organizes numerous binary files stored within a storage account that can contain multiple blob containers, and a container that contains multiple binary files.

Blob Storage Service

The Windows Azure blob is divided into two types, the block blob and the page blob, respectively, as described below.