Cloud storage: Building the Information "bank"

What is cloud storage? An internet entrepreneur said: "We do not care whether you are distributed, is not xxx, I as long as you can give me to save things, can be taken, it is finished." Is not the cloud also does not matter, as long as can obtain quickly. "Yes, this is cloud storage.

The purpose of cloud storage is very simple, is to save data, and just save data. Cloud storage does not attempt to understand and analyze the content of the data, nor does it consider the relationship between the data and the organization of the data. Cloud storage holds only one data object. However, user action data objects require an identity. This has a "key". Cloud storage requires users to upload a data, the name for it, that is, key. Data objects are often called value. The user sends a data pair to the cloud store while writing the data. While reading, cloud store send key, it will get the corresponding value (or "Data does not exist" feedback information, if the cloud storage does not exist corresponding key). In cloud storage, the size of value usually covers a large range, small to several bytes, up to dozens of hundred gigabytes.

Cloud storage is functionally a super large map that maintains mappings from Key->value. But the simplicity of the function does not represent the simplicity of the system, the size of which determines everything. As a massive storage system for huge user groups, the cloud storage system itself is a huge server cluster. On the one hand, cloud storage consolidates a large number of server storage resources into a single system, forming a unitary data storage entity. On the other hand, cloud storage needs to replicate multiple copies of each user's data and spread it across different servers to ensure the reliability of the data, which we call "replicas." Finally, in the face of a large number of users of high pressure access, the load must be distributed to different servers, so as to give full play to the overall effectiveness of the system.

These technical features cause cloud storage to be a very special type of distributed system that needs to be specifically designed and developed. Specifically developed systems are relatively highly reliable and highly available. Some storage services try to provide services with other uses of distributed storage systems, and often do not achieve the desired results. The domestic cloud storage started late, specially developed cloud storage is relatively rare. At present, only the "Grand Cloud" has built a new dedicated cloud storage system to provide real cloud storage services.

Although the functionality of cloud storage is simple, it provides services that are essential for most network applications. Unlike traditional PC software, which provides simple information processing functions, network applications focus on the exchange of messages and tend to multimedia more and more. As a result, Web applications save a large amount of user data, including pictures, videos, music, documents, and so on. and Internet applications rely more on the size of the user base to gain benefits. A large number of customer base will produce a huge amount of data storage requirements. On the other hand, the miniaturization and mobility of terminal equipment has become an obvious trend. More and more applications use mobile devices such as mobile phones and tablets as primary target clients. These lightweight devices cannot support large-capacity data storage. At this point, cloud storage becomes their ideal data depot. In turn, the advent of cloud storage makes the development of these mobile applications more convenient and quicker. It can be said that cloud storage will greatly promote the development of mobile applications, as a powerful catalyst for mobile internet.

We're not going to be installing a big safe in the house to keep all the cash. We will get a safer and more convenient savings service from the bank. A company rarely raises a few boats, or a group of transport planes, to ensure their shipments. They will buy transportation services from the logistics companies. Our society is highly specialized, people do not have to build their own facilities to serve themselves. Similarly, Internet applications do not need to build storage clusters of their own to get services from cloud storage at a much lower price.

Cloud storage services are purchased on demand, and the cost can be increased incrementally as the business progresses. For small-scale Internet applications, entrepreneurial enterprises, etc., more practical significance. These budget-limited projects do not need to invest a lot of resources to build data storage systems at the outset, and precious funds are nailed to a variety of hardware and software facilities. There is no need to be bothered by the scale of the system when the scale of the business expands rapidly. Using cloud storage enables projects to be more flexible, freer and more efficient in terms of capital investment and cash flow.

Cloud storage is a booster of internet entrepreneurship. Developers can focus more on the design, development, and operation of the application itself, while delegating the task of building, operating, and managing the storage system to cloud storage. With the support of cloud storage, the entrepreneur can complete the application in the shortest time and seize the opportunity in the fast-changing Internet market.

At present, in the industry, major IT giants have been involved in the field of cloud storage. Amazon's S3 is currently the main cloud storage service provider. Other companies have launched such products, including Google's Google Storage, Microsoft's Live Mesh, EMC's Atmos, IBM's XIV, and so on. The domestic cloud storage started late, but developed rapidly. Shanda Cloud Computing invests a lot of resources, developed the domestic first specialized cloud storage system. Other domestic internet giants have also unveiled their own strategies for cloud storage. Predictably, future cloud storage services will boost the innovation and development of SMEs.

(Responsible editor: Duqing first)