http://www.microsoft.com/china/msdn/library/archives/technic/develop/windna/0314d.asp
Windows DNA: Establishing Windows Applications for Internet Age
Stephen Rauch Microsoft is responsible for operating system platform strategies and architects
Summary: Discuss Microsoft's Windows DNA structure. Including: Microsoft's idea for collaborative components
Three-layer application model scalability to existing systems and database compatibility
Now, individual computers that are getting stronger and more powerful, and price will be lower, whether it is a big company or a small company is building more powerful applications. Every day, these applications are used by hundreds of users, but new forces have had a profound impact on software developers now develop application software and their development and configuration application platform. As the application of Internet technology is increasing, global information sharing is possible (not only from or large or small companies, but any individual). Due to the operation of 24 hours a week, the Internet has activated new creativity in many ways, resulting in many new industries suddenly emerged overnight. Competition and increasing changes are in further demand for application platform, and in order to obtain strategic advantages, this platform should make application software developers can create faster and higher configuration adaptive applications. Considering these new Internet applications need to handle hundreds of thousands of users - just a few years ago, it is still very possible now. Therefore, the application software needs to handle the number of users, which relies on 24 hours a day and to flexibly meet the changing business needs. As the foundation platform for these various applications, the application software model must also be provided with a set of next-layer construction and a first built-in service program that enables these new applications to develop and manage.
Figure 1. Windows DNA
Microsoft's application software platform consists of two parts: a multi-level distributed application model - Windows DNA (Figure 1), a comprehensive underlying construction and application software service procedures. Windows DNA (http://msdn.microsoft.com/isapi /gomscom.asp?target=/dna/) unified the service program on your personal computer, the application software server, and the top three of the current hosts; The intrinsic of the Internet technology of the client-server computing system and the application software structure of public basic components. Simply put, the guiding principle of Windows DNA is:
In the Internet. Development solutions should completely develop the flexibility of the application software platform, the global range of the Internet and the communication capabilities that meet demand.
Quickly enter the market. Development configuration solutions should be quickly and do not need developers to receive re-education or learning software how to develop examples. Through the basis of "lead products" to reduce the number of code that developers must prepare, this reveals services and functionality.
Real compatibility. Development should be compatible with all levels, so functionality can be added to an existing system. Adhere to open protocols and standards, so other vendors can be integrated.
Reduce complexity. Turn some key services directly into the operating system and reveal them in a unified manner through components. Reduce the needs of information technology experts, only as system integrators understand their functions, so users can concentrate on solving business problems.
Language, tools and hardware needs. Provides a component model-independent component model so that developers can use task-oriented tools. Developed on a PC computer model, users can configure solutions based on a broader hardware.
Reduce the overall cost of users. Developing applications should be easily configured, managed, and modified at any time.
As long as the correct lower structure is given, such a multi-layer model consisting of the business logic and data can be physically assigned to multiple computers. However, the core abstraction of a layer or two layers of models in the past is used as a high-grade programming language, database management system, graphical user interface - does not fully meet the needs of multi-level application development. Developable, manageable, manageable multi-user applications require abstraction of different layers, in Microsoft, we believe this abstraction is a collaborative component. Collaborative component
Microsoft's Windows DNA strategy depends on the prospects of its collaborative components, which is established based on the binary standard called the Component Object Model (COM). Com (http://msdn.microsoft.com/isapi /gomscom.asp?targt=/com/) is the most widely used software component model in the world, and now there is now 150,000 table-sided computers and On the server. It offers a wide range of integrated services that can be widely used, and you can provide a complete set of applications. In addition, it provides a commercially available market for the available Customer-server components that can be reused.
COM allows software developers to write application applications from the binary software components that can be configured at any level of the application model. These components support packaging, split, and distributed application functions. COM can also use component development applications with any form of code compression or application feature, such as one user control interface or linear commercial object. One component may have one or more interfaces; each of them can be described by a set of methods and attributes that can be accessed by other components and applications. For example, one user component can be described by various attributes such as name, address, and telephone numbers.
Due to Microsoft's Windows DNA model, components reduce the complexity of developing multi-layer applications. Applications based on components and Windows DNA models depend on a set of basic underlying construction and network services provided by the Windows application platform. For example, Microsoft's Windows NT security services provide access control for Internet Information Server (IIS), and things and message queue services. Other basic services include system management, directory services, network, and hardware support.
User environment and representation
Many application software developers using collaborative components will now develop their application software to the Windows platform to make full use of the rich user interfaces provided by Windows. Similarly, users have gradually wanted to get rich and powerful user interfaces from the application. The Internet can provide users with as much information and services, which have brought new challenges to application developers. Today, application software developers must develop distributed, user interfaces that are commonly used on Windows and Non-Windows platforms, and support a wide range of user environments from hand-held wireless devices to high-end workstations. However, application software must have a feature, so it can be competitive and constantly provide the user's expectations.
Figure 2. Windows DNA representation
As shown in Figure 2, Windows DNA provides a wide range of representations that allow application software developers to choose when developing best solutions. Windows DNA allows developers to choose a suitable Windows component and Internet technologies to support as many interfaces as possible (from hand-held devices to high-end workstations).
In order to adapt to as many user environments to obtain compatibility for all browsers, application developers often use standard HTML languages to develop their independent browser applications. Microsoft's development tools and application software services support the current generation of HTML languages.
The cost of using a static HTML language is to reduce the functions and rich content of the application software user interface, and this is the user's hope. This may be suitable for some applications because they require broad and independent of the browser.
But there is a class of applications that don't need to be independent of the browser. In fact, many companies have their own separate browser standards. In addition, those who want to provide more features than the standard HTML language in their applications, and write code mainly depends on the browser used. These enhanced browser applications can make full use of the browser inherent techniques to achieve maximum features and benefits. With the application of technologies such as dynamic HTML language and scripting, application software developers can create a web interface-based action without using traditional Applet controls for data access and reporting. DHTML is based on W3C standard document object model, which makes all web page elements into programmable objects. Ten DHTML consider "programmable" HTML. The content of the HTML document - includes style and location information - can be dynamically modified by script source code embedded on the web page. Therefore, the script can freely modify the style, content, and structure of the web page without having to refresh the web page on the web server. In doing so, customers do not have to repeatedly access the web server for increasing network performance in order to constantly change the web. DHTML is not like Java Applets or Microsoft ActiveX controls, which does not depend on the lower-level virtual host or operating system. For the user, if there is no support for DHTML, its content seems to be low.
Sometimes DHTML and script are not sufficient. Some parts of the application need to use the operating system and the lower host host, and maintain the Internet for data or additional services. In these aspects, application software developers can use powerful components and Internet services provided by Windows to create applications that depend on the Internet. A Internet-based application is not like web-based applications, which is a complete Windows executable, which can fully use any services provided by Windows users. These applications typically use HTML, DHTML, SCRIPTING, and Active controls to provide integrated services to client systems and connecting Internet remote services.
On the application platform that supports the Win32 Application Interface (API), the application software written in Microsoft Win32 API provides powerful features. By using collaborative components, today's developers use Internet technology based on WIN32-based applications on the Windows application platform. These applications that are written as WIN32 API utilize the advantages of the operating system and the Internet of Internet, known as enhanced Internet applications. This example is like Microsoft Office 97 and Microsoft Visual Studio 98 development system. These applications can support unified browsing by nesting the hyperlink in the application, and can log in to the browser for files written with DHTML and download the latest version of the application software on the Internet.
Application software service
Figure 3. Application software service
The business logic layer is the core, special software processing and business rules of the application. The business logic layer in the component links the user environment and the data layer. After years of improvement, the Windows DNA application software platform has supported large-capacity, large-scale, transaction-processed application software configuration, and also provides a powerful operating environment for accessing business logic components. As shown in Figure 3, the platform for developing Windows applications includes web services, messaging services, and component services.
Web service
Microsoft's integrated application software platform is a high-performance representation layer pathway. Microsoft's Internet Information Server (HTTP "// msdn.microsoft.com/isapi/gomscom.asp?target=/ntserver/nts/, then click" Web Services ") makes it easy to develop web-based commercial software, These software can be extended to the entire Internet or on intranet. By using IIS, Microsoft introduces a new example-transaction processing application in the Internet. Transaction application makes running real configured fast easy telescopic High reliability commercial software is possible.
Dynamic Server Web Page Technology (ASP), one component of IIS is independent of the language-free assembled server script environment that can be used to create run dynamic interactive web server applications. Based on DHTML, Scripting, and components, ASP enables application software developers to create dynamic interactive web content and powerful web-based applications. With the increasing application of distributed calculations in the enterprise environment, communication between applications is flexible and highly reliable. Even if the application does not run simultaneously, commercial applications also require applications that run in different systems to communicate or exchange information independently. The application software created by the ASP script that uses collaborative components can be interoperable between existing systems, applications, and data.
Component service
In the early 1990s, the basic concepts of facilitating interoperability are componentization; the basic techniques of achieving interoperability are COM. As a result, componentization is not only an important method for realizing interoperability, but also an important way to design and develop universal software. Therefore, in the mid-1990s, Microsoft has widen the scope of COM, and it is extended from desktop applications to distributed applications by introducing Microsoft Life Processing Server (MTS). The COM planning model provides services for the development, configuration and management of components based on components, and MTS is an extension. The application software platform can be convenient for distributed application applications under the Windows platform. As its foundation, MTS is simpler than other methods smaller.
COM is the next generation of COM and MTS improvements. The unity of the inherent planning model in COM and MTS services makes it easier to develop distributed applications, and can be eliminated for applications that use COM (for a particular service) and MTS (for other services). Monotonic differences in development, commissioning, configuration, and maintenance. This is the benefit of the application software developer lies in making the development of distributed applications easier and less cheap by reducing the number of code used for the underlying system services.
By expanding COM and other services in MTS 2.0, COM consists of an improvement and new service of existing services of the application software platform. include:
Produce your own things. The COM component can be added to the work processing of the COM Work Processing (TP) environment-supported Internet Location Processing Protocol (TIP). Secret expansion. Support for confidentiality based on task confidentiality and process access. In task-based privacy models, access to different parts of application software is agreed or rejected based on logical groups or tasks assigned by the caller (eg administrator, full-time employee or part-time employee). COM extends the current task-based application by confidential levels for traditional and iDispatch (EX) interfaces. Centralized management. Component Services Explorer, a substitute for MTS Explorer and DCMCNFG now, provides a unified management model, which makes it easier to configure, manage, monitor N-layer applications by eliminating a large amount of personal management tools in use. easy. Built-in database. The built-in database maintains steady state and transient information in a compatible manner. The built-in thing-processed database system can query data at very fast speed on the machine. Queue components. When collaborative components are separated, it can be used asynchronously, but except for session-based synchronous client / server planning models, the client can keep logically and event notifications here. Sometimes a loose connection event notification mechanism is necessary, COM event is a little / multi-point, published / subscribe mechanism, which allows multiple clients "subscribe" by different servers "published" events. This is not in the existing event notification framework passed by the connection point. Balanced load. Balanced loading allows components-based applications to allocate their workload in a transparent manner to clients through an application string.
Interoperability on existing systems, applications and data
Since many companies are gradually developing to the Internet, providing new services, providing more accessible information for their users, partners, and employees, and therefore important, the application software structure can provide the company's internal extensive application software and data necessary Methods. Some software vendors advocate a public component model with a language that can be run on any platform to package your existing applications so you can implement interoperability between application software and data. This is a high goal, it has been promised for thirty years ago, but it still has no results now. Microsoft's approach has been experimenting on existing applications and data on other platforms, and the results are not damaged. Therefore, Microsoft's application software platform allows application software developers to interoperate application software and data by using a message service, COM. Framework that is called universal data access. Message service
Microsoft Message Queue Server
(http://msdn.microsoft.com/isapi.gomscom.asp?target=/ntserver/appservice/exec/overview/msmq overview.asp) provides a reliable network communication on the basis of a message queue model service. MSMQ makes an integrated application easier by performing a propulsive business event delivery environment between applications, making it easy to develop reliable applications running on a network that is unreliable but a small price. Simple application on COM, make developers can centrally commercial logic instead of mature communication programs. MSMQ also provides complete interoperability to other message queue products, such as IBM's MQ series, and products that can be obtained from Microsoft's Independent Salers (ISV) collaborators.
Host things to handle the extension of the world
Using Microsoft COM Listing Processing Integrated Environment (TI) and COM components, application software developers can extend and reveal complex command processing Computer (CISC) and Information Management System (IMS). COM TI consists of a set of development tools and runtime services, which automatically converts IBM hosts and commercial logic as a COM component running in a Windows DNA environment. All COM TI processing is performed on the Windows NT server, and login communications can be completed via the SNA server (http://msdn.pacerosoft.com/isapi/gomscom.asp?target=/sna/). The COM TI does not require a host to run any executable code or program in any dedicated manner.
General data access
General Data Access is a policy for Microsoft to provide information access to enterprises (http://msdn.icrosoft.com/isapi/ gomscom.asp? Target = / data /). Today, because each company wants to get the largest commercial interest from distribution in large amounts of data and information distributed in the company, they are facing many challenges when studying database solutions. General Data Access provides high performance access to various information sources, including relational and non-relational data, and is easy to use independent of tools and language programming interfaces.
General Data Access does not need to move those data to a single data store, nor does it need to be responsible for a developer's product. General Data Access is based on an open industrial specification with extensive industrial support, you can work on all existing main database platforms.
Figure 4. Data Access
As shown in FIG. 4, the frame based on the general data access is active in two hierarchies. On the system layer, the OLE DB defines the component-based determined architecture as a set of COM-based interfaces that compress a variety of database management system services. OLE DB structure does not limit the type of data source; • target = / data / oledb / products / products.htm). On the application layer, the ActiveX Data Object (ADO) provides a advanced interface to enable developers to access data from any programming language. in conclusion
The Windows DNA structure and the Windows NT platform provide many significant advantages to users and their ISV collaborators. Its main advantage is:
Providing a comprehensive platform for distributed applications such that developers can completely get rid of an obstruction of the desired lower layer structure and use a segment determination method to assemble it. The existing enterprise application software and the traditional system of the traditional system can easily expand the existing system. By providing an in-depth component model, extended pre-construction applications and broad choices for programming languages and support tools, making it easier for development distributed applications.
