Middleware Learning--initial knowledge

This is the time to learn the contents of the middleware, and from this article we begin to learn about middleware content.

Development Overview

Before learning middleware knowledge, we first understand the development of software development technology, from the software development technology step by step development of the middleware technology, and now we begin to introduce the development of software development technology.

1. Host-based Systems

Host-based systems are only the beginning of the hardware and program composition, this time the program has not been divided into operating systems and applications, after a long period of development, people slowly found that the program has a stable component that is the calculation of resource management This part, people according to the stability of the program can also be said to be a common ingredient, This part of the common component is the operating system, people from the program generated the operating system and separate the application.

2. Two-layer client/server system

at the end of the host-based system has evolved into hardware, operating systems and applications now it's two tiers CS The initial state of the system, the two-tier CS The development of the system, people from the application to find the common elements of the program is data management, in this case, people from the application of the database management system has been separated from the application software.

3. Three-tier (n - tier) architecture

two-storey CS The system finally developed into hardware, operating system, database management system and application, which is already N layer architecture of the initial state, people from the application software to discover the common elements of the program is the network resource management, in this case, people from the application software generated from the application server middleware and separated the business logic (component).

at this point the system N layer architecture, mainly divided into hardware, operating system, database management system, Application Server (middleware), Business logic (component) , Web The presentation layer.

Because of the diversity of operating system, complicated network programming, management, complex and changeable network environment, the consistency problem brought by data dispersion processing, performance and efficiency, security, etc., the common problems to be faced by application software are refined and abstracted, and a reusable part is formed on the operating system. Reusable for thousands of applications. The idea of this technology finally formed the middleware software.

Why use middleware

Middleware is in the middle of operating system software and user's application software. There are four reasons why we use middleware mainly: usability, performance, data integrity, control ;

Ease of use in other words, using middleware can be used to shield the differences of network hardware platform and the heterogeneity of operating system and network protocol, so that application software can run smoothly on different platforms.

Performance on the middleware load balancing, connection management and scheduling has played a big role, so that enterprise-class application performance has been greatly improved to meet the demand for the critical business.

Data integrity refers to the use of middleware to transfer data, data can not easily be lost and duplicated, data format is not easily destroyed.

Control is a layer of software between the middleware operating system and the application system, which provides support for the development, deployment, operation and management of distributed applications, and provides services for distributed system requirements: Remote method invocation, transaction, load Balancing, failback, security, etc. can be done well.

Middleware in the operating system, network and database, the application of the lower layer of software, the overall role is to be in their own upper layer of application software to provide a running and development environment, to help users flexible and efficient development and integration of complex application software is the development, deployment, operation and management of distributed applications to provide support.

What is middleware

Middleware is a kind of basic software, in the operating system (or network protocol) and distributed applications, thereby shielding the operating system (or network protocol) differences, to achieve the interoperability between distributed heterogeneous systems.

At present, the middleware has not formed a unified definition, the more recognized IDC definition is:

Middleware is a kind of independent system software or service program, the Distributed application software uses this software to share resources among different technologies, the middleware is located on the operating system of the client server, and manages computing resources and network communication.

Middleware should have two key features: first for the upper layer of the Application layer service, this is a basic condition, in addition, it must be connected to the operating system level, but also maintain the operational state, with such two characteristics can be called middleware.

We have further introduced the concept of middleware,

Middleware is a kind of software, not a software

Middleware not only interconnect, but also interoperate between applications

Middleware is based on distributed processing software, the most prominent feature is its network communication function

Middleware is a common service between the platform (Hardware and operating system) and applications, i.e. middleware = platform + communication

Middleware working mechanism

Middleware is an API -defined distributed software management framework with strong communication capability and good scalability. Applications on the client need to obtain certain data or services from somewhere on the network, which may be in an operating system server that is running and different from the client. the part of the client / Server application that is responsible for finding the data simply accesses a middleware system by invoking the middleware API . A data source or service is found in the network by the middleware, which transmits the customer request, reorganizes the reply information, and finally sends the result back to the application's task.

PostScript

Knowledge about middleware This article is introduced here, the next article we continue the knowledge of middleware.

Middleware Learning--initial knowledge