Delight in Thinking

Cloud computing is not a technical nature, but a new mode of information processing and transmission. It can be defined from different perspectives cloud computing, such as technical support from the point of view, cloud computing is an important technical support for virtualization technology, virtual technology can be achieved through the sharing of computing resources, virtual technology is not a new technology, Its development can be traced back to the early stages of computer technology, especially in the mainframe - terminal mode, the number of terminals can use the same host of computing and storage resources. Later developed to the client - server model, the client has its own computing power for local processing, while the server data. The emergence of the Internet has changed the mode of the computer network, in particular the emergence of Web, making the client - server model has become more simple and clear, the formation of the browser - server model. This model can be said that the embryonic form of cloud computing.

Cloud computing is accompanied by development of the Internet to form a new computing model, the model is based on the network, use the word cloud of this romantic mode to name this calculation, it is entirely from the network, People often use the network cloud icon to indicate when the cloud paint more and more, icons, system structures almost always have to draw clouds to represent the Internet, the cloud would be independent, to form a specific pattern, This model is called Cloud Computing.

Cloud computing model is a fundamentally Internet profile, in the 这个 mode, the entire Internet as a Le a super computer, people can do most of this supercomputer to calculate Ren Wu, implementation of the information processing and Chuan Di, Zhe is cloud. When the Internet became a super computer, people's computing model is complete a cycle, that is, the calculation mode back to the original - host mode, that Internet users are using a computer, which is a virtual technology as a support of this computing model of core technology. Virtual technology is a complete multi-level architecture, including hardware layer, the platform layer, application layer level, including the completion of a computation, to achieve all the components of computer applications. The core of this architecture is how to integrate the various components to form a complete independent system. So, what is the adhesive bonding of various components? The answer is simple: service.

Service became the core of cloud computing, the cloud model, all are services. Infrastructure into a service that iaas; platform into a service that paas; software into a service that saas. If we extend this concept to the general level, that is xaas. Therefore, cloud computing is a basic equation:

Cloud computing = XaaS, all are service!

Here, we need an explanation of the services in the cloud computing model, the service has a broader meaning, it not only refers to the system to provide the services and, in a sense, more importantly, the system and systems of services, that all the services are services, including services to users, including system services, in other words, both human services, including service on the machine. When we establish a cloud computing service that all basic equations are after, then Renhe Yun computing is the process of solution of this equation,

Application of our library of cloud computing is the process of solution of this equation, if we will build in the cloud computing model known as cloud Library Services under the Library, then the cloud library can be expressed with this formula:

Cloud library = LaaS, that cloud is the library as a library service.

In the context of cloud computing, the library as a service consists of four aspects of meaning:

1. Library is web-based information services, libraries should be drawn in the application icon inside the cloud. In other words, the library should be a cloud;
2. Library network to provide information services to end users, that cloud is a network of libraries should exist;
3. Library system through the network information service, which goes into a large library exists in the network database, other applications can be seamless integration of library information;
4. Library system and other systems should be seamless to integrate access to other resources.

In the cloud computing environment, the library service as a kind of information and knowledge-based infrastructure, the cloud computing model is a function of layer architecture, the library is a ubiquitous cloud.

Dedication to be held in Shanghai, "Cloud Computing and Libraries" Conference

Debate between technology and humanity is very boring, because it is well aware that should not be controversial. Areas such as business studies, the emergence of electronic commerce by business studies in hot pursuit, not seen what people say service is the first of the exclusive e-commerce. Technology extends the service, which is not discussed, the success of e-business shows a very simple truth, that is in the Internet age, any service can only structure on the strong technical support. Library Services, of course can not be an exception. But it is a lot of the library community, "smart people" do not see these, do not know if this is "smart people" or the library community sad sad. Some people also plausibly play the "Library is the institutional arrangements," the slogan that I have to ask what social institutions are not institutional arrangements? If anything, what arrangements library, then there is no doubt that the library is a technical arrangement.
Some people may not opposed to technology, heart and even agree that the importance of technology, they are only opposed to "technical rescue plan", and they feared they would be excluded from the technology loop, unable to participate in a grand plan to save the cause of such concern very cute, but not necessary. Technical rescue plan is not a matter of several technical experts, but all librarians do. Xiamen University has a very great institutional innovation - "balls." "Balls" cause I do not know, but the "balls" all those who love the museum's entire focus on the development of young people concerned about libraries, regardless of what position they are, what background, IT experts, Ye Hao, cataloging experts Ye Hao, Circulation of library assistants or whatever, can join the "balls", "balls" as a cross-sectoral, multi-disciplinary, technology as the core business areas related to the entire library of technical innovation team, to bring together books Museum of technology building blocks, a library technology innovation engine, idea database, and I think this should be the Xiamen University Library in the field of technological development led the industry in the important reasons. Mechanism of rice balls, not only in Xiamen University library, but we can at the Shanghai Library, Peking University Library, Shanghai Jiaotong University Library and other large library to see the shadow of rice balls, these libraries are all technology leader. Rice ball is a great mechanism for innovation in this mechanism, each person can put a library to the library of technical innovation and the development of the flood, how exciting it is? Those who oppose the rescue plan technical people, why not get rid of the burden into the torrent to this?
Technical rescue plan is something all librarians, not just technical experts of things, but technical experts put the figure in the technology undoubtedly played an important role. However, the library of technical experts been marginalized public libraries, library technology experts, when the whole world enjoy the high-wage high-status, our technical experts been marginalized, this is not normal. I remember, and "technical rescue plan" put forward the slogan author to discuss the reason, he deeply marginalized for library technology sector concerned, technical department have a lot of talents, to carry out important functions, they should be more concern and attention, play a greater role. I am sure he is right is for the library's future development vision. This is what I have spared no effort "technology to save map" beating the drums of reasons.
In fact, like me, an ordinary librarian, can only be none other than the edge of a hand shouting numerous refueling only, sometimes crying out of the throat, were you one with a set of all the offset. I can do is be a clown just forwarding you laugh, and you have to have a much bigger role, which is why I suddenly want to write this letter to you.
Professor Cheng, your generation is worthy of respect and library scientists, because of your drum-banging and hard practice, our library from a bureaucratic institution-oriented services into a service-oriented social institutions, it is 30 years, the library has undergone a revolutionary leap, you Laohuai so humble, this generation of library scientists in the crowd are our idol. Service was in the library's survival and continued development of the foundation, we are deeply identified with the idea of your services, but services and technologies are not contradictory, emphasizing technology services is not necessary to exclude the cost of the rapid development of modern technology today , services and technology are inseparable in fact, technology that is service, service, technology, we can not separately to each other. Technology development is always beyond one's imagination, but also contrary to people's feelings, I know you have a deep love of books that will give you great joy scholarly, but technology is changing, times are changing, we The new generation of users is no longer emotionally attached to books, so that they no longer intoxicated is scholarly, but the mouse Titicaca sound. How do we do? We can not put Confucius used bamboo spread on the table, forcing the young man after reading, we can not treat addiction as as electric shock readers do not read. The only thing we can do is to change our service model, our services into their familiar environment to go, this is the basic concept of technical rescue plan. Professor Cheng, Professor of you as a librarian and a director of a large academic libraries should be able to resonate.
Professor Cheng, you may look down on technical drinkers, even you may look down on modern technology, but live in a technological world, you may be unable to avoid the technology, since technology can not be avoided, why not refuel for the technical applause? Maybe you another point of another position, contribution to the development of the technology would be enormous.
Technology exploration is a painful process, lonely process is under great pressure of the process, technology drinkers not only have the intelligence, more should have strong willpower. In my mind, these strong library technology explorers is a hero. I can not become a member of them, but would like to applaud them, but also urge Zhubozhaizhu to where we are cheerleaders, we were together cheering for the technical drinkers. Ok?

This topic is very luxurious, encompasses many of the current hot area of information technology terms, from Web2.0 to cloud computing, these terms constitute a bright Web world from the past into the future road map.

The life cycle network around the world is a stage of ten years, from the first generation Web experiences to Web2.0 about 10 years, 10 years, Web address of the person's interaction with the network problems, from Web1.0 Just read the network information to provide users the convenience to the development of Web2.0 to provide users with interactive access, from, Web is not just a media, but rather an information exchange platform to communicate with each other. In the Web2.0 environment, users do not just Web-readers, but also Web content providers and participants, today, Web2.0 basic Web has matured and become mainstream. Web2.0 site full of large networks, and nurture a large number of users, it can be said, Web2. Really fostered the rise of a virtual network society.

W eb2.0 A key feature is involved, that Web users can participate in Web content development. This is a surface feature, in this feature is the technical architecture behind the changes, Web1.0 is mainly a web form, but to the Web2.0, HTML is no longer a Web-based, but the application system, in particular, is called of the content management system (CMS) for Web applications, Web1.0 to Web2.0 development is from the Web Page to Web Application Development Changes.

This kind of structural change in technology has changed the basic properties of networks, Web is no longer an isolated site were linked through the network, but a variety of Web application integration, Web content into functional and integrating through a whole into a large system. In order to achieve this integration, need to be addressed in the Web environment, communications between systems, especially functions and data reuse problem, so gave birth to Web Service framework, such a service-oriented architecture to become a landmark structure Web2.0 . Therefore, from a technical architecture perspective, Web2.0 feature is that Web services Web Service.

W eb as a large distributed system requires not only open the Web Application services (Web applications), also need to be structured description of data. Only through a structured description of data, application systems can be understood, in other words, an effective distributed network applications need to have the machine can understand the data. If Web2.0 is built on open service architecture, then a new generation of networks will be built on the basis of a machine can understand the structured and interrelated with the data environment, once the data environment established, then the Web will enter a new era, this new Web environment, we can call Web3.0.

W eb3.0 to be addressed is a data representation, allows the machine to understand the data structure information, the data structure information is called the semantic information, which is the core of semantic networks need to address the problem, so the Semantic Web can be viewed as is Web3.0 start. Semantic Web has experienced a development from concept to reality the process, its technical architecture has become increasingly clear, that is of concern associated with the data (Linked Data). There are two basic points associated data that describe and connect. Description and links are for machine service, the machine can be achieved by describing the automatic discovery and confirmation of the link can support the machine automatically link.

We go back and look at web1.0, 1.0 conditions, the browser get information from the server directly displayed on the screen, do not know the meaning of information, web pages and link each other through hyperlinks, but the need to manually click the trigger, 2.0 by the machine to automatically aggregate all kinds of information, and to 3.0, the network in the data layer on the establishment of a link mechanism, the data structure information is well described with, and through the URI to ensure that the machine can automatically link to a variety of data, to achieve intelligent automation of information aggregation.

Then, cloud computing is not the natural effect?

L inked data can be the basis for a new generation of Semantic Web has a very broad application prospects. W3C recently announced, SKOS Linked Data will be full of. (Needle, 2009) which is significant for the library community. SKOS of the linked data should benefit from the libraries of the United States Congress, the Library of Congress Subject Headings (Library of Congress Subject Headings) of all the Linked Data, Linked Data application to become a successful example, promoted the Linked Data to practical. This in turn can be said that libraries contribute to the development of the Internet instance.

L inked Data is based on RDF and http protocols, in other words, Linked Data is to pass through the Http RDF data, and the RDF data is a special rule to follow the semantics of data, this rule is that any resources are characterized with a URI. So URI \ RDF \ HHTP constitute the three cornerstones of Linked Data. The application of any Linked Data revolve around these three aspects of the. Such as:

• How to build a resource URI?
• How to create RDF resources?
• How to use http to transfer RDF?
• How to accept and parse RDF data resources? And so on.

L inked Data Application There are two basic models: a model for the browser / server mode, that people through the browser to access Linked Data; The other model is a client / server model, where clients mainly refers to the application system, the model is actually the system and data transfer between systems. Whatever the mode, Linked Data is to pass through Http.

H ttp protocol actually defines two processes, one request, the other is the response. To these two processes as the blueprint, we can simulate a Linked Data transfer process.

• Client-side or browser sends a request to the RDF file server, requests the server to return an RDF document. Send this request is simple, you can directly enter a rdf file suffix, such as http://www.cloudlibrary.info/rainzenfoaf.rdf rdf is a simple request. Of course, this request is very weak, the file suffix is not necessarily with the rdf for RDF format, in turn, RDF format file suffix it may not rdf. So, to pass with the file extension is not very reliable RDF request. What we need is a mandatory request RDF very clear way, this request can only be through the system (such as the browser) rather than be issued manually. Now a common browser can not issue such a request, in order to apply Linked Data RDF we need to send the requested browser.
• RDF when the server receives a request, need to return an RDF document, and inform the client that this is a RDF file. This process is called content negotiation. To achieve this RDF-based content negotiation, which would set the MIMEType, the definition of an RDF type. RDF 2004, one on the content type: Application / RDF + XML to be registered. Linked Data on the terms, content negotiation is very important, if you want to publish Linked Data, require the server can implement content negotiation.
• Device sent a service response to a client, particularly the browser, how to parse the RDF file? Particularly in the browser mode, because RDF is not for seeing, but to the machine to see how the machine language translation of the expression of adults to read? This in turn requires a special browser to parse RDF.

View from the process, applications linked data needs:

• RDF can send a request, and be able to resolve RDF browser, we call RDF browser. Keven described in his blog a lot of RDF browser or plug-ins. (Wei, 2009)
• A server to return RDF type of server. Fortunately, we often use the Apache open source http server: that is one of the few to achieve a good content negotiation server.

Linked Data released in the use of Apache, the need for a simple Apache settings, need to increase the one on RDF's content-type, is set in Apache, or in. Htaccess to add a type description: AddType application / rdf + xml rdf . This Apache receives a request for RDF, RDF type can send messages back.

However, as application / rdf + xml is a new registration, and some browsers do not compatible, I found a phenomenon, visit http://www.cloudlibrary.info/rdf/rainzenfoaf.rdf when the software by checking the file header that, the server returned an application / rdf + xml document, but by Firefox to see the file information, been interpreted as text / html. It seems firefox's default content-type is text / html, and not authorized application / rdf + xml type, when receiving this type, only use the default value.

Another interesting phenomenon is that, Apache's default type is text / plain, if no RDF type, the server can not confirm RDF file to start the default value, the RDF file as text / plain. Return the text file information, then the browser displays text files. So, is the need to increase application / rdf + xml then this type? Is not necessarily a matter of fact, already stated, FireFox the application / rdf + xml interpreted as text / html, then we add a type: AddType text / html rdf also line, or directly to the Apache's default value is set to text / html on the line. So how do you explain the return to send over the text / html message, the browser was able to resolve it into RDF? It seems that the browser client also needs a judge, by analyzing the markup language to determine whether the RDF file. However, in the communication between systems, I think, or should be enabled application / rdf + xml, so clearly more reliable.

This text is formed during the discussion and Keven, thanks to Keven contribution to this article.

References:

Needle, David. 2009. W3C's New SKOS Standard Advances Linked Data. [Online] August 18, 2009. [Reference date: August 27, 2009.] http://www.internetnews.com/dev-news/ article.php/3835176 .

Wei, Liu keven. 2009. Associated data browser. Number Chart Research Notes. [Online] August 26, 2009. [Reference date: August 27, 2009.] http://www.kevenlw.name/archives / 1844 .

Background Links

http://www.w3.org/Protocols/

http://www.iana.org/assignments/media-types/application/