I. Overview
1. Concept of middleware
With the rapid development of computer technology, a variety of applications need to be transplanted between various platforms, or a platform needs to support multiple applications and manage multiple application systems, soft, hardware platforms, and application systems. Requireability and efficient data transfer or conversion, so that the synergy of the system is guaranteed. These, there is a need to construct a soft and hardware platform, and the software system that provides support for the upper-level application software, while the middleware is pregnant in this environment.
Since the middleware technology is in the development process, it is currently not exactly definition.
Comparative popular definitions are: Middleware is a separate system software or service program that distributed applications share resources between different technologies. The middleware is located on the client / server operating system, manages computing resources and network communication.
As can be seen from the definition of the middleware, the middleware is a class of software, not a software; middleware not only implements interconnect, but also interconnects between applications; the middleware is based on distributed processing, The network communication function is particularly emphasized in the definition.
2. Middleware characteristics and advantages
Usually, the middleware should have the following features: to meet the needs of a large number of applications; run in a variety of hardware and OS platforms; support distributed computing, providing interactions with transparency across network, hardware, and OS platforms Function; support standard protocols; support standard interfaces.
Programmers use a large number of APIs provided by calling middleware to realize the communication of heterogeneous environments, enabling complex operating systems and network protocols in the heterogeneous system.
The middleware provides connection services between clients and servers that have standard program interfaces and protocols. For different operating systems and hardware platforms, they can have a variety of implementations that meet the interfaces and protocol specifications.
Since the standard interface is important for mutual transplantability and standard protocols for interoperability, middleware has become a major part of many standardized work. For application software development, middleware is more important than operating system and network services, the program interface provided by the middleware defines a relatively stable high-level application environment, regardless of how the bottom-level computer hardware and system software are replaced, as long as the middleware Upgrade updates and keep the interface definitions of the intermediate pieces are unchanged, and the application has almost no modification, which protects the company's major investment in application software development and maintenance.
Middleware is an independent system software or service program, distributed applications share resources between different technologies. Middleware software manages communication between client programs and databases or early application software.
Middleware plays a role in distributed customers and services, such as transaction management, load balancing, and web-based calculations.
Using these technologies help to reduce the burden of application software developers, make them more mindful when using existing hardware devices, operating systems, networks, database management systems, and object models to create distributed applications. Since the middleware can protect the investment of the company, ensure the relative stability of the application software, to achieve the application software function expansion; the simultaneous intermediate parts are largely simplified a complexity of the distributed processing environment consisting of different hardware, so it The emergence is increasingly attracting attention.
The world famous consulting agency THE STANDISH GROUP summarizes the top ten advantages of the middleware:
(1) Application development: The Standish Group analyzes the proportion of business logic programs, application logic programs and basic procedures in 100 key applications; business logic programs and application logic programs account for 30% of total programs, while The basic procedure accounted for 70%, and one of the traditional senses can save 25% to 60% of the application development fees. If the application is combined with a new generation of middleware products, the application development costs can be saved to 80%.
(2) System operation: There is no application system using middleware, its initial funds and operational costs are more than double more than the application system of the same size. (3) Development Cycle: The development of basic software is a time-consuming work. If you use standard commercial intermediates, it can shorten 50% to 75% of the development cycle.
(4) Reducing the risk of project development: Research shows that the failure rate of the key application system development project without the use of standard commercial intermediates is higher than 90%. Enterprise's own development of built-in foundations (middleware) software is not compensated, and the total expense of the project is even twice, even more than ten times.
(5) Reasonable use of funds: With standard commercial intermediates, companies can easily add new functional modules from or outside or outside of the existing or legacy system, and seamlessly collections them with the original. Relying on standard middleware, you can change your old system to change your face into a new Internet / Intranet application system.
(6) Applications: Relying on standard intermediates to combine existing applications, new applications, and purchased business components together for application collection.
(7) System maintenance: It is necessary to mention that the self-development of the base (middleware) software is to pay very high cost. In addition, the expenditure of the basic (middleware) software for self-developing is required for development costs. 15% ~ 25%, the maintenance expenses of the annual application also requires about 10% to 20% of the total cost of the project. In general, purchase of standard commercial intermediates only 15% to 20% of the maintenance fees, of course, the specific price of middleware products should be based on the quantity of the product and which manufacturer.
(8) Quality: Based on the basic (middleware) software platform based on enterprise self-construction, each additional new module is added to the foundation (middleware) software. The standard middleware is clear and specified in the interface. Standard Middleware Standardization Modules can effectively guarantee the quality of application system and reduce maintenance expenses in new and old system.
(9) Technology innovation: The frequent innovation of the company's basic (middleware) software platform is extremely difficult to achieve (not practical). To purchase standard commercial intermediates, the development and changes in technology can be assured that the middleware manufacturers will grasp the technical direction and conduct technological innovation.
(10) Increase product attraction: Different commercial intermediates offer different functional models, reasonable use, allowing your app more easily add new performance forms with new service items. From another perspective, reliable business middleware also makes the company's application system is more perfect and more.
Specifically, the middleware shields the complexity of the low-rise operating system, so that the program developers face a simple and unified development environment, reduce the complexity of the programming, and focus on their own business, do not have to be procedures Dressing in different system software, thereby greatly reduces technical burden.
The middleware brings to the application system. It is not only the development of the development, the development cycle is shortened, and the workload of the system is also reduced, and the workload of the system is also reduced, and the overall computer overall cost is reduced. The STANDISH GROUP survey shows that due to the use of middleware technology, the total construction cost of the application system can be reduced by about 50%. Today, in the development of the network economy, today, from the middleware, it is not just IT manufacturers, IT users are also the winner, and it is more grasped winners.
The middleware is a new level of basic software. Its important role is to integrate application software on different operating systems in different operating systems. It is the operating system, the database management system itself cannot be can't do with one of the overall coordination of a sky. This role of the middleware, after the continuous development, making it used in the application software, saving a lot of manpower, financial investment. 3. The application areas and classifications of middleware
With the development of computer software technology, middleware technology has also matured, and there are different levels, different types of middleware products. The middleware can be divided into six categories according to the Idc classification method. Data Access Middleware, Remote Process Calling Middleware, Message Middleware, Trading Middleware, Object Middleware, etc.
Data Access Middleware: It is an intermediate member to establish a data application resource interoperability, and the database implementation of the joint or file system implementation of the intercourse;
Remote Procedure Call Middleware: Through this remote process call mechanism, programmers write client applications, which can call the procedure on the remote server;
Message Middleware: Used to block the characteristics between various platforms and protocols, communicate with each other, implement the cooperation between applications;
Trading Middleware: A environmental platform for ensuring transaction integrity and data integrity in distribution and heterogeneous environments;
Object Middleware: In distribution, heterogeneous network computing environments, various distribution objects can be organically combined, complete the fast integration of the system, and implement object reuse.
At present, many manufacturers at home and abroad have developed their own middleware products, including the world's largest independent middleware manufacturers, as well as IBM, ORACL E and Microsoft, HP, Sun, etc. have also been involved in e-commerce. Part.
Object-oriented middleware is the product of object technology and distributed computational development. The industry generally believes that object-oriented is the mainstream direction of future intermediate parts. It provides a communication mechanism that transmits object requests in transparent distribution computing environments. And these objects can be located local or remote machines.
Object-oriented standards originally only one, that is, CORBA (public object requesting agency architecture), which is developed by many manufacturers including BEA, IBM, Oracle, Sun and Sybas E, which form a huge CORBA Alliance. power. Later, Sun launched an enterprise JavaBeans (EJB), which has improved CORBA with the program model of yourself. The appearance of Microsoft COM (Component Object Model, Component Object Model) makes more standards in the object-oriented middleware market, so that object-oriented middleware products actually form two standards, one is Microsoft COM, one is Javabeans.
From a macro look, the middleware can be divided into 3 categories:
Data classes: Used for data access, utilization, and value, such intermediates are used to construct data-centered applications.
Treatment class: Connect the various applications or processes distributed on the network node to form a unified distributed application.
Distributed components: support component applications, future application development, current competition is fierce.
We divide the middleware into 12 kinds. Details are as follows:
Number of kinds of advantages and disadvantages 1 Database system product management database connection, abstract network protocol. The database vendor is generally provided by a database vendor or a multi-database middleware to provide database vendor's product function and better performance. The products independent of database vendors are used in multi-database environment to reduce Oracle Net8Sybase Netlib, Protocol Services INTERSOLV Sequelink Client 2 Data Inventory Access API supports programming for data stocks, and stored procedures. The OO database is an OO programming language, such as Java / C provides an access to ODMG interface database vendors to support access to all databases, and thus suitable for writing OLTP applications. ODBC or JDBC is more suitable for the environment IBM DB2 CLIORACLE NET8, CALL INTERFACROSOFT ODBC, OLE DBODI'S PSE 3 data migration, converted to data deployment, conversion, and information value. Often as part of the data warehouse solution allows completely different packets and legacy applications to work together, but you need to establish a synchronization service such as time, data preferred, and integration, and resource equality IBM Data PropagatorSyBase Replication ServerPlatinum Infopumpd2k Tapestry 4 RPC) Make the process of calling the remote and the same locally. Calling processes are abstrained in the coded process in the called process, the code is abstracted, and only all the Server is online. Not suitable for mobile or Internet Application DCE-RPC (Microsoft uses it in the DOM) Borland EnteraNet RPC 5 Simple asynchronous message Simple is message sending and receiving, sometimes extending to reliable delivery, intelligent route and name service require high performance asynchronous Communication applications are very useful. However, all Server online PeerLogic PipesMomentum XIPC Oriental Technology Tonglink 6 Application level message queue is a simple message middleware extension, adding queues, offline processing capabilities, reliable delivery and release subscriptions such as distributed processing In the way, event-driven, etc., suitable for e-commerce, mobile users, workflow, or other environments Tibco Rendenousibm MQ Seriesmsms MSSAGE Queueevel8 Falconmq Oriental Tong Technology Tonglink / Q Tsinghua North America TH - MT 7 Application Coordinator is usually the application The extension of the level message queue adds many tools to establish integrated applications that are suitable for event services, effectively saving integrated time, especially for application packages or workflow products Vitria Velocitiactive Software, ActiveWeboboboldon Prosperpneon Neonettsi Mercator 8com / DNA Microsoft distributed components Platform, making business applications more expandable and manageable from COM, which is the mainstream products in the component market. It is also necessary to add reliability MS, COM, DCOM, COM MS MS MSMG standard for enterprise applications, connect distributed objects into a logically unified overall industrial organization, which can be used by ORB. Implementation to improve interoperability Iona OrbiXborland / Visigenic, Visibrokeribm ComponentBrokerbea Iceberg Oriental Technology Tongbroker 10 Transaction Monitor for developing real-time OLTP applications, for managing transactions, shared resources have proven to build OLTP applications Effective means.
Usually non-object-oriented, Apibea Tuxedoibm TX Series Oriental Technology Tongeasy Tsinghua North America JavaSt 11 Application Server For Internet, intranet, and other distributed component applications, providing the complete environment of the server component and the transaction monitor, It's just object-oriented, supporting components, standard Apinetdynamicsibm Compont - BrokernetScape Kivaracle App. Ser Eastern Tong Technology TongWeb Tsinghua North American WebFirst 12 Workflow / Application Integrated hodgepodge, combined workflow and application development technology such as messaging and distributed components To make it easy to automatically use the components, Script applications, and the work is integrated, integrated with documentation and email LSS Flowmanibm FlowMarkAction, Technologies, Actionworksvitria Business AgiTi 2, Middleware Technical Specification 1.DCE System
DCE is an abbreviation of the Distrbute Computing Environment distributed computing environment, which is developed by Open Software Fondation, and now this organization is called Open Group.
The DCE consists of multiple components that work together, they are: Remote Process Call (RPC), Local and Global Directory Services (CDS and GDS), Security Services, DCE Threads, Distributed Clock Services (DTS), and Distributed Files Service (DFC). Threads, RPCs, CDS, security services, and DTS components are often a security core, and is a component necessary for any DCE environment, and DTS is optional. In the DCE environment, management tools for managing these components are also included.
DCE is called a middleware or a technology that has its ability to exist independently, but is bundled in a vendor operating system or is integrated by a third party supplier.
2.DTP model
The DTP model is a software structure proposed by the X / Open organization, which allows multiple applications to share resources provided by multiple resource managers and have the ability to coordinate global things.
X / Open is an independent, global open system organization, which has been supported by most of the world's largest information system suppliers, which is fundamentally, anything to standardize the open system, from the viewpoint of calculation How to make users get greater benefits.
The X / Open's DTP model consists of 5 basic modules:
Application (AP): The boundary used to define things and determine the action that makes up the operation.
Resource Manager (RM): If a database or file system is used to access files.
Listing Manager (TP): Assign things identified, monitoring the processing of things and is responsible for the completion of things and the recovery of coordination of things failure.
Communication Explorer (CRM): Controls communication between or between the two matters or two matters.
The X / Open model between the five modules defines the interface specifications between such modules and modules:
Application-Explorer has existed some X / Open specifications, such as SQL and ISAM; TX interfaces are defined between the application - Listing Manager; between the Trading Manager - Resource Manager The XA interface is defined; there is three interfaces between the Trading Manager - Communication Explorer; there is 3 interfaces between the application-Communication Explorer: TXRPC, XATMI and CPI-C; in communication resource management The XAP-TP interface is provided between the underlying communication protocol provided by the operating system.
3.corba
Corba is an abbreviation of Common Object Request Broker Architecture. It is abbreviated as a public object request agency structure. It is developed by the International Object Management Organization OMG. This organization is an international organization. It is founded in 1989. It has now included in manufacturer and software developers. More than 800 members, the purpose is to provide a public framework for the development of application software in distribution and constructed computer environments, so that the development of the software is object-oriented and can be reproducible, portable, and operability. See Section III below for other functions of CORBA. 4.j2ee
J2EE is an abbreviation for Java 2 Platform Enterprise Edition, a multi-layer application mode structure system. The entire specification is proposed by Sun Company, which separates the business logic from the system service function and the user interface, placed between the two layers of the client layer and the application infrastructure, is the most widely used web-oriented application. System structure specification. See Section III below for other functions of J2EE.
5. Internet related technical specifications
Web (World Wide Web) is a networked information resource that relies on three mechanisms that make this information resources can face the vast users.
1) A unique naming mechanism, positioning the resources, such as: URI.
2) A communication procedure to access these named resources on the Internet, such as: http.
3) Mix the text to better drive these information resources, such as HTML.
Uri (Universal Resource Identifier) Global Resource Identification, a naming mechanism, which will be divided into 3 parts of a resource on the Internet: the name of the communication method for accessing resources, such as http, ftp; saved resources The name of the machine, such as: www.sohu.com; the name of the resource itself is to access the path to these resources. HTTP (Hypertext Transfer Protocol is a communication procedure for application layers for distributed, mutual collaboration, and hybrid media. Using this procedure, in addition to obtaining information in the information system, you can also perform a data query, update the front end and perform information.
HTML (Hypertext Markup Language) is a publishing language that provides the author with such a function: including title, text, table, list, list, list, etc. in the publication of the author; after pressing the mouse, by mixing text Link lookup text; with the remote service to create a table for information to perform information, booking, booking, and ordering products; directly containing separate pages, video data and sound information, etc. in the document.
These specifications are the foundation of Web technology. In addition to these technical specifications, there are also some norms that are also very important. Its use is to realize data exchange between enterprises and enterprises through Web. These specifications are XML, SOAP, UDDI, and WSDL.
Vxml (Extensible Markup Language) Improves the web function by providing more flexible and more easily received information identification methods. XML is called scalable labeling language, it is not like HTML is a single, pre-defined language, XML is a language for describing other languages, using XML, you can define your own, not type Limited, other types of documents.
SOAP (Simple Object Access Protocol is a lightweight procedure for exchanging information in a distributed environment without a control center. It consists of XML, consisting of four parts: an envelope, defined what information and how to process it; a set of encoding rules, a representation of the application defined data type; a group represents a remote Process calls and responses are rules, and a set of bundling modes, this way is used to exchange information using low-level communication procedures. SOAP has the possibility of combining with other rules. UDDI (Universal Description, Discovery and Integration) is a specification that is used for web services to register with web-based information. UDDI is also a public accessible collection of such specifications. This specification is provided by the content of a company's Web service, so that other companies can discover these services. Web services are the next development direction of Web technology, which allows programmable to be placed on the web, others can access in a distributed manner.
WSDL (Web Service Description Language) is a set of XML format network service descriptions that contain endpoint operation information for document or process messages; operations and messages are first abstracted, then bundled into specific network procedures and message formats for Define endpoints, associated specific endpoints are combined into the abstract endpoint (service). WSDL can bundle with SOAP, HTTP GET / POST, and MIME.
Third, the mainstream middleware technology platform focuses on and compares the three mainstream middleware technology platforms to deepen the readers to deepen the technical understanding of middleware.
1. Platform currently supports server-side middleware technology
Taking the current mainstream distribution calculation technology platform, there are mainly OMG CORBA, Sun's J2EE and Microsoft DNA 2000. They are all platforms that support server-side middleware technology development, but they have their own characteristics, which will be set forth below.
(1) OMG CORBA
The CORBA distribution computing technology is the public object requesting agency system specification based on the distributed objects of the distribution objects submitted by many open system platform vendors based on many open system platform vendors.
CORBA distribution computing technology is the system specification technology supported by most distributed computing platform manufacturers, with a full range of models, advanced, independent system platforms and development languages, and has been widely formed. Standard. The COBRA standard is mainly divided into 3 levels: objects request agency, public object services and public facilities. The bottom layer is the object request proxy ORB, specifies the definition of distribution objects (interface) and language mapping, communication and interoperability between objects, is the "soft bus" in the distribution object system; there are many public services to the ORB. It is possible to provide a wide range of services such as concurrent services, name services, transaction (transactions) services, security services; the top-level public facilities define the component framework, providing services that can be used directly to business objects, specifying business objects The agreement rules needed to work effectively. Currently, CORBA-compatible distribution calculation products have ended, including middleware manufacturers' ORB products, such as BEAM3, IBM Component Broker, product launched by liberal objects, such as Ionaobix and Oocobacus, etc.
The recent development of the CORBA specification increases the characteristics, service quality control and CORBA Component Model facing the Internet.
Internet integration features include a firewall (FireWall) and Naming Service, which defines the URL naming format for IIOP transmission. Service quality control includes an asynchronous message service capable of quality control, a set of request schemes for real-time CORBA and fault tolerance CORBA for embedded systems.
Corba CCM (CORBA Component Model) is based on the CORBA specification (after version 2.3) that supports PoA, it is developed based on the current specifications of the EJB. The CORBA component model is a server-side middleware model specification for the development and configuration of distributed applications, which mainly includes the following three items:
a, abstract component model to describe the structure of the server-side member structure and inter-component interoperability;
B, component container structure to provide general components operating and managed, and support integration of system services such as security, transaction, persistent status;
c, the configuration and packaging specifications of the component, CCM uses package techniques to manage components, multilingual version of executable code and configuration information, and make specific contents of the component package and XML-based document content standards.
In summary, CORBA is characterized by large, interoperability and openness. The disadvantage of CORBA is a large and complex, and the technology and standard updates are relatively slow, and the time of the COBRA specification is very short from 1.0 upgrades to 2.0, and the release of the release is relatively slow. It is not a lot in specific applications.
(2) Sun's J2EE
In order to promote Java-based server-side application development, Sun has launched Java2 technology and related J2EE specifications at the end of 1999. J2EE's goal is to provide platform-independent, portable, supported and accessible access, and safe, based on Java-based Develop server-side middleware standards.
In J2EE, Sun gives a complete Java language-based development-oriented application specification, where J2EE supports RMI and IIOP, while the constructor of server-side distributed applications, including Java servlet, JSP (Java Server page), EJB and other forms to support different business needs, and the Java application has the characteristics of "Write Once, Run Anywhere", so that J2EE technology has developed rapidly in the field of publishing computing .
J2EE simplifies the components expandable, which is the complexity of component server-side applications, although DNA 2000 is the same, but the biggest difference is that DNA 2000 is a product, J2EE is a specification, and different manufacturers can realize their own J2EE specification. Products, J2EE specification, is a numerous manufacturers to develop, it is not unique to Sun, and it supports cross-platform development, and many large distributed computing platform manufacturers have publicly supported J2EE compatibility technology.
EJB is part of the Java-based server-side component specification J2EE, which is launched by Sun, has been widely developed since J2EE is launched, and has become standard technologies for application server. SUNEJB technology is based on the local components of Java Bean, developing application components for server-oriented distribution applications. It is based on Java language, providing a reuse of Java binary bytecies. EJB gives the system's server-side distribution component specification, including the interface specifications of components, component containers, and standard specification content such as component packaging, component configuration, and the like. The introduction of EJB technology makes it possible to use Java based component-based development server-side distributed applications. From the perspective of the multi-layer structure from the enterprise, EJB is the middleware technology of the business logic layer. Unlike JavaBeans, it provides the ability to transaction, since the three-layer structure is proposed, the intermediate layer, the business logic layer, is a handling transaction The core, separated from the data storage layer, replaced most of the storage layer. From the perspective of distributed calculations, the EJB is the basis for distributed technology like CORBA. Providing communication means between objects. From the perspective, EJB and Servlets, EJB and Servlet, JSP become a new generation of technical standards, and the Bean in EJB can be divided into session beans and entity beans, former maintenance sessions, the latter handled transactions, now servlet is responsible for the client Communication, access EJB, and return the results to the client through the JSP generation page. The advantage of J2EE is that the mainstream of the server market is still a large machine and UNIX platform, which means that "WRITE, RUN Anywhere" can be configured to include any server, including Windows platform, with Java development components. Go in the environment.
(3) Microsoft DNA 2000
Microsoft DNA 2000 (Distributed Internet Applications) is Microsoft to extend the distribution calculation model, and the new distribution calculation architecture and specification that is extended after the distribution calculation model, and the retrofit BACK OFFICE series server-side distribution.
On the server side, DNA 2000 provides applications for ASP, COM, Cluster, etc. Currently, DNA2000 has huge advantages in technology structures. On the one hand, since Microsoft is an operating system platform manufacturer, DNA 2000 technology has been strongly supported by the underlying operating system platform; on the other hand, due to the extensive application of Microsoft operating system platform, the number of application development manufacturers supporting the system platform has many times, so In practical applications, DNA 2000 has been adopted and supported by many application developers.
DNA 2000 integrates today's most advanced distribution calculation theory and ideas, such as transaction, scalability, asynchronous message queues, clusters, and more. DNA enables development of server components that can be based on Microsoft platforms, such as database transaction services, asynchronous communication services, and security services, are provided by the underlying distribution object system. DCOM / COM / COM camp headed by Microsoft, from DDE, OLE to ACTIVEX, etc., provides the basis of middleware development, such as VC, VB, Delphi, etc. Support DCOM, including OLE DB, new data inventory, With the release of Windows2000, Microsoft's DCOM / COM / COM technology, on the basis of the DNA2000 distribution computing structure, a new distributed component application model is displayed. First, the components of the DCOM / COM / COM still use a common COM (Component Object Model) model. COM initially serves as a Microsoft desktop system, mainly for local OLE applications, but with the release of Microsoft Server Operating System NT and DCOM, COM has extended component technology to distribute applications. DCOM / COM / COM will extend it to a business logic middleware for a server-side distribution application. With COM related service facilities, such as load balancing, memory database, object pool, component management and configuration, etc., DCOM / COM / COM combines COM, DCOM, MTS's functionality, forming a concept, strong Component application architecture. Moreover, the DNA2000 is a single manufacturer's distributed object component model, and developers use the series of development tools provided by the same manufacturer, which is more attractive than a combination of many developments. However, it is insufficient to depends on Microsoft's operating system platform, and thus does not work on other development system platforms (such as UNIX, Linux).
2. Correlation comparative analysis
At present, there is a similar and comparable distributed component, which is similarly and comparable distributed components, which is the CORBA CCM (Corba Component Model) technology, and the EJB (Enterprise JavaBean) technology and COM / COM / DNA 2000. DCOM / COM technology.
For the above three distribution computing platforms, this paper uses the industry commonly used practices to analyze the following three aspects:
Integration: Integration is mainly reflected in the basic platform support for application interoperability. It requires distribution on different machine platforms and operating systems, all kinds of business applications generated by different languages or development tools must be integrated to form a unified enterprise computing framework. This integration framework must be based on the network and have integration capabilities for legacy applications;
Availability: The software component technology required to require must be mature technology, and the corresponding products must also be mature products, which can operate stable, safe and reliably in critical enterprise applications. In addition, since the database plays an important role in the enterprise calculation, the software component technology should be able to closely integrated with database technology;
Scalability: The integrated framework must be scalable to coordinate different design patterns and implementation policies, which can be cut according to the needs of enterprise calculations, and can quickly respond to market changes and development trends. Protect your investment by ensuring the reusability of current applications.
The following table gives the comparison results of the above three mainstream distribution computing platforms from three aspects of integration, usability, scalability.
Although these three platforms have different historical backgrounds and commercial backgrounds, their own focus and characteristics are, in fact, there is also a lot of exchange and complementarity.
Fourth, middleware is the basic software for realizing e-commerce
The essence of e-commerce is to communicate and coordinate a variety of computer systems in the distribution environment, thereby opening a new business operation mode. Network communication, especially Internet technology, is the communication foundation of e-commerce, and business information between management and transmission systems, coordinating the intermediate management service system of various systems processing modules, is the key to ensuring the success of e-commerce applications. E-commerce application servers, universal business gateways, payment gateways, communication platforms, and security platforms, unified into the scope of the e-commerce middleware architecture. From a technical point of view, e-commerce will consist of Internet / Intranet technology, traditional IT technology, and specific business processing. However, the establishment of the system will face many new problems, including application systems can be established quickly, can adapt to large users, high-processing requirements, can provide high efficiency, high reliability, high availability, etc. Key tasks The requirements can not meet safety needs, and so on.
These issues are only not enough to rely on simple Web technology. Currently used Web technology is due to the early premature information release, there is a number of problems that visit bottlenecks, difficult to expand, low efficiency, and safety, and cannot meet the needs of e-commerce. In order to solve these problems well, it is necessary to plan a whole application framework based on the low-level technology of Web, and provide a support platform for the development, deployment and management of Internet applications, and can solve the above various problem. This has developed into a widely adapted standard support layer, which is an infrastructure, which is actually based on Internet-based middleware, which is the application server.
At the same time, since the company does not cross the business, it must be combined with the traditional application system, and therefore also integrates the web application and traditional applications through the middleware to achieve complete e-commerce.
In this case, the e-commerce application should contain the following levels:
● Browser: This is the channel to enter e-commerce.
● E-commerce application platform: Provide electronic commerce different application types of build tool software, such as online stores, network payment, virtual communities, etc.
● E-commerce exchange platform: Interior of various business systems related to e-commerce within the integrated enterprise, external connection business partners, such as banks, suppliers, customers, distribution structures, and complete data conversion between different business systems and Whole.
● E-commerce base platform: Concurrent access to a large number of Internet customers, enabling application developers to quickly develop flexible and variable e-commerce applications, putting information systems and business activities into the Internet as soon as possible.
There is no in the e-commerce exchange platform and the e-commerce base platform, there is no intermediate. It can be said that there is no intermediate that cannot support today's web application.
E-commerce middleware architecture is a key component of e-commerce applications, regardless of the distribution of e-commerce applications, what database system is used, through which interconnects and interoperabilities of e-commerce applications It is the problem that the e-commerce middleware architecture first needs to be solved. In terms of communication, e-commerce middleware architecture should support various communication protocols and communication service modes, transmit various data content, data format translation, traffic control, data encryption, data compression, etc., in the core of the electronic commerce middleware architecture, Solve the name service, security control, concurrency control, reliability and efficiency guarantee; in terms of e-commerce application development, it is necessary to provide rich development interface based on different platforms, support popular development tools and heteroanifier connection standards; In terms of management, the configuration, monitoring, tuning of the electronic commerce middleware architecture itself is solved, providing guarantees for ease of use of e-commerce applications.
Second, there are various requirements for the e-commerce middleware architecture for different web applications. For workflow applications, the information, information, response status are required to be delivered to another according to conditions and conditions, and the information, and the online transaction is handled, and the distributed data consistency is required, and the operation is not stopped. For a data acquisition system, it is necessary to ensure reliable transmission, etc. 5. The middleware is in line with the trend of software development.
Software Component technology is born under the inspiration of large industrial production. It is a development trend of software technology cross-century. Its purpose is to thoroughly change software production methods, fundamentally improve the efficiency and quality of software production. Improve the success rate of developing large software systems, especially commercial systems. With software components, the application developers can assemble applications for different fields and functions in different areas. The multiplexing software has always been the dream of the entire world software industry. The software component is achieved to achieve this dream pointing out a practical road, and the middleware is a form of component software. Middleware abstracts typical application modes, application software makers can develop based on standard forms, making software components into possibly, accelerating the process of software multiplexing. Therefore, the middleware is inherent in line with the inherent law of software development.
The middleware is a trend of software technology development, known as the fastest growing software variety, strong in recent years, of course, this is also supported by the market on the middleware. There is no doubt that middleware is becoming new technology and economic growth points in software industry.
