March 9 2nd Assignment-System integration knowledge

1. What are the characteristics of information system integration?

• Information system integration to meet user needs as the fundamental starting point

• Information system integration is not the choice and supply of equipment, more importantly, it has a high-tech engineering process, to the user needs to provide a comprehensive solution, the core is the software

• The final delivery of system integration is a complete system rather than a separate product

• System integration including technology, management and the morning and other work, is a comprehensive system engineering. Technology is the core of system integration work, management and morning activities are the guarantee of the successful implementation of system integration projects.

2. What phases are included in the development phase of the information System lifecycle:

• Master Planning Phase

• System Analysis Phase

• System Design Phase

• System implementation Phase

• System Acceptance Phase

  Note: The life cycle of information system can be divided into 4 stages: project, development, maintenance, extinction

3. Software engineering focuses on four types of maintenance, including the type and applicable conditions

• Corrective Maintenance: The SOFTWARE PRODUCT is delivered and modified to correct the problem found

• Adaptive maintenance: Modified after delivery to keep the SOFTWARE PRODUCT in a post-numbered or changing environment CAS continues to use

• Improved maintenance: Modified after delivery to improve performance and maintainability (50%~60%)

• Preventative maintenance: Modify after delivery to detect and correct potential errors in software products before they become actual errors

4.UML the characteristics

• Not a visual programming language, but a visual modeling language

• is a modeling language specification, is a standard representation of object-oriented analysis and design

• is not a process, nor a method, but allows any process and method to use it

• Simple and extensible with extended and proprietary mechanisms for easy expansion without modification of core concepts

5. software architecture, what are some common architectural patterns, and the pros and cons: 103

• Pipe/Filter Mode,

• Advantages: 1 The characteristics of "black box" and low coupling of high cohesion are embodied in each function module.

  2 The input/output behavior of the entire system can be viewed as a simple synthesis of multiple filter behaviors

  3 ) supports reuse of software function modules

  4 facilitates system maintenance, new filters can be added to existing systems and can be replaced by improved filters

  5 support for specific analysis such as throughput calculation, deadlock detection, etc.

  6 supports parallel operations, each filter can be completed as a separate task

  Cons: 1) usually result in a batch operation of the processing process

  2 requires the designer to coordinate two relatively independent, but still relational, data flows

  3 each filter may need to do its own data parsing and compositing work (such as encryption and decryption), resulting in degraded system performance and increased complexity of the filter implementation.

• Object-oriented mode

  Pros: 1) highly modular 2) package function for data hiding 3) inheritance provides a means of implementing code sharing 4) provides system flexibility to facilitate maintenance and expansion

  Cons: Calls between formations need to know the identity of the called object. If an object's identity changes, all objects that call the object must be notified, or the system may not function correctly

• Event-driven mode

  Pros: 1) Support software reuse, easy to implement concurrent processing 2) has good scalability, through registration can introduce a new build, without affecting the existing build. 3) can simplify customer code

  Cons: 1 The component weakens its own control ability to the system. When a component triggers an event, it is not possible to determine the other components in response to the event and the execution order of the individual components 2) is not a good solution to the data Exchange Problem 3) is a component of the system of the drain relationship becomes more complex

• Layered mode

  Advantages: 1) Help to decompose complex problems by function and make the overall design clearer 2) support system design step-by-step abstraction 3) with good scalability 4) support multiplexing

  Cons: 1 Not every system can be easily divided into layers; there is no unified, correct abstraction method for the division of the functions of a colleague. 2) Too many levels, system performance may degrade

• Knowledge Base Mode

• Client/server mode client/server,c/s, based on resource misalignment, is proposed for the realization of sharing.

  Advantages: 1) The client and the server are separated, allowing the network to distribute the operation; the development of the two can also be done separately 2) a server can serve multiple clients

  Cons: 1) The communication Dependence and network of client and server may become the bottleneck of the whole system operation; The client is overloaded, it is difficult to manage a large number of clients, the system performance is greatly affected 2) if the server and its interface definition change, then the client will make corresponding changes 3) two layer C/ S-mode is single-server and LAN-centric, which is difficult to extend to the WAN or the Internet. 4) data security is not good. The client program accesses the database service directly, making the security of the database compromised.

  C/S The model is suitable for distributed system, and in order to solve the client problem in C/S mode, the browser/server mode B/S is developed. In order to solve the service problem in C/S mode, the three layer (multilayer) C/s mode is a multi-layer application architecture. Various architectural modes are not mutually exclusive and can be used synthetically.
  

6. What are the characteristics ofWeb Services , what are the typical technologies, and what are their respective uses?

• Defines a loose, coarse-grained distribution calculation pattern that uses the standard HTTP (S) protocol to deliver XML representations and encapsulated content.

• Typical techniques include: Simple Object Access Protocol soap for conveying I-type milkshakes, Web Service Description Language WSDL for the service, unified description for registration of Web services, discovery and integration of UDDI, XML for data exchange

• Web The main goal of the service is cross-platform interoperability, where Web services is appropriate (1) cross-firewall (2) application integration (3) business-to-business integration (4) software reuse, where Web service is not appropriate (1) Single application (2) homogeneous application on LAN

7. Computer network knowledge, networked storage mode contains three patterns, what are the characteristics of each

• DAS Direct-attached storage, which is directly connected to a series of computers by the memory and the server

• NAS Network-attached storage is the connection of a storage device to a series of computers through a standard network topology. is a storage structure that is both powerful and flexible, with a focus on helping workgroups and departmental agencies address the need to rapidly increase storage capacity. NAS products are truly plug-and-play

• SAN Storage Area Network is a network storage technology using high-speed fibre Channel as transmission medium. In general, sans have extremely scalable, simplified storage management, optimized resource and service sharing, and high availability.

March 9 2nd Assignment-System integration knowledge