What is MDA? What is the difference between it and other architectures? MDA is a new way for writing specifications and development applications, which is based on platform-independent models (PIM: Platform-Independent Model). A complete MDA specification contains: 1, an authoritative UML-independent model-independent model PIM; 2, one or more models related to a specific platform PSM; 3, interface definition set - each collection describes the basic model and different middle Implementation on the platform platform. A complete MDA application contains: 1, an authoritative PIM; 2, one or more PSMs; 3, one or more complete implementations - Developers decided to implement applications on all platforms supported. MDA-based development first focuses on distributed systems or applications, rather than which specific technique is implemented. The MDA is separated by the business logic and the detail. Therefore, whenever a new technique (such as XML / SOAP) comes, we don't have to repeat the process of modeling the system or application, while other architectures tend to be bundled with some specific technologies or platforms. Unable to achieve this. With MDA, we only need once to model the function and behavior of the system, and it is only once. The work of PSM maping PIM to a particular platform is automatically completed by the tool. When we need to support new technologies, this simplifies our work. Why is OMG to develop in a new direction? What is the reason for driving? If you re-examine OMG development history, you will find that in fact, MDA is not a new direction. In 1997, OMG expanded its work range and received work using UML and MOF. Although the platform-independent UML model can be implemented on any platform, the problem is that as the project progresses, the UML model and the implementation often appear to appear, and it is not well synchronized - the stump is still fixed on the ground, but over time The organizational structure around it has changed. MDA defines a good modeling standard (not only to Corba, but also in the past, now, all other middleware technology), will be created, or will be created, or The application is integrated. The MDA improves the threshold for design work, which is designed to design light and household operations at this level. What role does UML play in MDA? UML is a key to enable MDA technology: all applications created using MDA technology are based on standardized, platform independent UML models. By using this generic, universally accepted modeling standards, MDA enables developers to create a useful interoperability, naturally with good interoperability applications. Moreover, these applications can be accessed by an application of an embedded system, a desktop application system, a server, a large machine, etc., and can also be accessed across the Internet and have broad application prospects. What role played in MDA in MDA? In MDA, a specification PIM is used to define one or more PSM and interface definitions. Each definition describes how the base model is implemented on a different middleware platform. Due to the PIM, PSMS, and interface definitions will be used as part of the MDA specification, OMG will adopt a variety of middleware platforms. CORBA technology has the independence of platforms and languages, and has been tested transactions and safe nature. This makes it still from an embedded system to the desktop system and to the best choice to the Internet application. The direction of MDA is to make it easier to interact with other middleware platforms, and it is cheaper. Where will CORBA go? OMG will continue to develop CORBA and promote its development. The market of CORBA will continue to expand, especially in real-time embedded, large tasks, high-capacity-to-error in enterprise computing environments.
Since CORBA is a solution for only integrated multi-platform, many companies will use CORBA to create and integrate applications defined by MDA. OMG and its members have always approved the value of interoperability with other standards (such as platforms and languages with all rights). OMG created a COM / CORBA interoperability standard in 1995 and expands it in 1997, and also designed and established Corba and Java, XML synergy. MDA will continue to define interoperability of intermediates and will provide tools to accelerate and automate this process. This will bring benefits to users because he will find its own application to support multiple middleware platforms. How does the MDA make the cross-platform interoperability possible? Whenever a new MDA specification or application is created, and other specifications, and interoperability of the service are already included in the design. In MDA, the basic description of each service, tool, and application is a platform-independent model. In the platform-independent model environment, architects can specify the application to the needs of the service, tools, and other applications, and use it as part of the model. Based on these models, the MDA tool automatically generates program implementations for connecting different intermediate platforms. What services are available in the MDA environment? OMG organization members know the need to be scalable services for companies or distributed computing across the Internet. For CORBA, the answer to the same problem is Corbaservices, which has been defined and available. In MDA, it has given a new name - a general in-depth service (Pervasive Services). Because each service is implemented to ignore the platform it run, a cross-platform bridge generated by MDA can serve any applications and client program services that require their capabilities. In MDA, OMG will quickly define 4 services: Directory Services * Service (SECURITY SERVICES) * Security Services * Distributed Event and Notification Services Other services, For example, it is recommended for services such as the Corba Services list, which will be added when needed to make the MDA environment has integrity. How will the field related software and standards benefit from MDA? MDA has many advantages for industrial software, so that some Domain Task Forces of Omg have begun to use MDA to write their standards, even if MDA has not become an official standard. In order to benefit a industry, a standard must be used by a large number of companies. Standard with specific technical bindings Because the inability to compatibility of the platform will bring trouble to large-scale promotion work. Sometimes the problem may be serious than this: In some industries, some architectures are very excellent, but the standards that are officially adopted have not been applied, because it is just written for a particular platform, and this platform is only Very few companies are used. MDA completely clears this obstacle. In MDA, each standard functional description makes it unrelated to implementation techniques, and its architecture is also possible to generate interoperable code implementations on a variety of platforms. This allows an industry to define their business logic functions and behavior as a PIM and then generate PSMS and various platform implementations. How does MDA and Microsoft .NET and Sun One? How to compete? MDA works at a level different from .NET and One. .NET and ONE are platforms owned by individuals, aiming at specific applications. The MDA is a model-driven software architecture that works above any middleware platform hierarchy including .NET and ONE.
