3.9 Second Assignment

Chapter III Information System Integration Professional technical knowledge

First, the information system integration of the salient features:

1. Basic starting point: to meet user needs;

2 . Not only equipment selection and supply, but also has high-tech content of the engineering process, to provide users with comprehensive solutions, the core is software;

3. The final deliverable is a complete system;

4. including technical, managerial and commercial work, is a comprehensive system engineering. Technology is the core of system integration work, management and business work is the guarantee of successful implementation of the project.

Second, the information system development phase includes: overall planning stage, system analysis stage, system design stage, system implementation stage, system acceptance stage.

Third, the type of software maintenance:

1 , Corrective maintenance: Modifications made after the delivery of the SOFTWARE PRODUCT to correct the discovery of the problem.

2 , serviceability: Modifications made after delivery of the SOFTWARE PRODUCT to keep the SOFTWARE product in a changing or changing environment that can continue to be used.

3 , perfect maintenance: Modifications made after delivery of software products to improve performance and maintainability.

4 , preventative maintenance: Modifications made after delivery of software products to detect and correct them before potential errors in software products become actual errors.

Iv. Unified Modeling Language (UML) features

1 , not a visual programming language, but a visual modeling language.

2 , is a kind of modeling Language Specification description, is an object-oriented analysis and design of a standard expression.

3 , not a process, nor a method, but allows any process and method to use it.

4 , simple and extensible, with extended and proprietary mechanisms that are easy to scale, without the need to modify core concepts.

5 , providing support for advanced concepts emerging in object-oriented design and development, such as collaboration, frameworks, patterns, and components, emphasizing reuse of architectures, frameworks, schemas, and components in software development.

6 , and the best software engineering practice experience integration.

Several common architectural patterns and their main advantages and disadvantages

1 , pipe/filter mode. Main advantages: High cohesion, low coupling.

2 , object-oriented mode.

Typical applications are component-based software development.

Key advantages: Highly modular.

Disadvantage: Calls between objects need to know the identity of the called object. If an object's identity changes, you must notify all objects that call the object. Otherwise the system may not function properly.

3 , event-driven mode

Rationale: A component does not invoke a procedure directly, but instead triggers one or more events.

Key Features: The event's trigger does not know which artifacts are affected by the event. It is not possible to assume the order in which the artifacts are processed, or even what procedures are called, and typical systems that use event-driven patterns include a variety of graphical interface tools.

4 , layered mode

Typical applications are layered communication protocols, such as the Iso/osi seven-tier network model.

Main advantages: The complex problem according to function decomposition, so that the overall design clearer.

Main disadvantages: (1) Not every system can be easily divided into layers, at the same time, the division of the functions of each layer does not have a unified, correct abstract method. (2) The number of levels is too large, system performance may be degraded.

5 , Knowledge Base mode

The typical application of Blackboard systems is the field of signal processing, such as speech and pattern recognition.

Blackboard system mainly consists of three parts: knowledge source, blackboard data structure and control.

6 , client/server mode (CLIENT/SERVERC/S)

Powerful data manipulation and transaction processing capabilities.

C/S mode is suitable for distributed systems. In order to solve the problem of client in C/S mode, the development has formed ( browser/server browser/server,b/S) mode ; to solve C/ S-mode server-side problems, the development of a three-layer (multilayer) C/S mode , that is, multi-tier application architecture.

Vi. WEB Services Technology

(i) Typical technologies for Web services

1 , Simple Object Access protocol for passing information (ACCESSPROTOCOL,SOAP)

2 , Web Service Description Language for describing the service (webservices description language,wsdl)

3 , unified Description, Discovery, and Integration (UDDI) for the registration of Web services

4 , XML for data exchange

( II) The primary goal of Web services is cross-platform interoperability, which is appropriate for use with Web serevices:

1 , cross-firewall, 2, application integration, 3, business-to-business integration, 4, software reuse.

In some cases, Web services can also degrade application performance. Scenarios where Web services are not suitable for use:

1 , stand-alone application, 2, homogeneous application on LAN.

Seven, network storage mode

1 , direct attached storage (DAS): A direct connection between the memory and the server, typically through standard interfaces, such as small computer system interfaces. Das products mainly include tapes, tape libraries, and optical storage products.

2 , network-attached storage (NAS): is the storage device connected to a series of computers through a standard network topology, such as Ethernet. NAS is a storage structure that has both a strong storage capability and considerable flexibility, with the focus on helping workgroups and departmental agencies address the need for rapid capacity increases. is true Plug and play.

3 , Storage Area network (SAN): A networked storage technology that uses (high-speed Fibre Channel) as a transmission medium. Sans have extreme scalability, simplified storage management, optimized resource and service sharing, and high availability.

3.9 Second Assignment