CMS Architecture and the standard three-tier three-tier client / server architecture is the basic corresponding. CMS three-tier architecture, there is nothing difficult to understand the content, are some common-sense things. It corresponds to a system each layer structure of the essential elements: interaction (interaction), action (manipulation) and storage. These three are:

Layer - to deal with user interaction and exchange.

Business logic (business logic) layer - process the user the information they need.

Database layer - stored all the data processing system.

Figure A visual representation of the CMS in the three-tier architecture. Figure A shows the layers are located on different machines, in fact, multiple layers can exist on the same computer, but their distribution in more than one computer in the CMS system can be better load distribution.

Figure A

Picture this topic are as follows:

CMS three-tier architecture

CMS n-tier architecture

In short, CMS n-tier architecture is the architecture of the CMS in all three layers into multiple layers, as shown in Figure B. Decomposition of the layer is to make the benefits of better coordination of the various layers to increase system performance; same time, this also makes the system distributed in more computers, thus reducing the system as a result of too many designated computer time-consuming bottleneck to improve the system load.

Figure B

Picture this topic are as follows:

CMS n-tier architecture

What layer?

While that level is not necessarily more important than the other layers, but it almost got all the glory - because it is the only CMS user can see the layers. This layer is responsible for the work of CMS and user interaction.

Layer actually consists of two parts: the Web client and Web server. Web client resides on the user's computer, usually used to accept the Web browser form (form). Web server host address in the Web, is used to generate dynamic Web pages and composition of the CMS system form.

Web client and Web server-side through the "request - response" way to communicate with each other. Web client makes a request to the Web server, Web server, according to a response.

Web client uses the HTTP request type. Such as:

GET / index.html HTTP/1.0User-Agent: Mozilla/4.0 (compatible; MSIE 5.0; Windows NT) Host: www.contentmgr.comWeb servers respond using the HTTP response. For example: HTTP/1.1 200 OKServer: Microsoft-IIS / 5.0Date: Thu, 12 Jul 2002 19:19:52 GMTConnection: Keep-AliveContent-Length: 1270Content-Type: text / htmlSet-Cookie: ASPSESSIONIDQQQGQGDC = MOFPDBPCPNIBACIBDCIOFCCL; path = / Cache-control: private ... </ BODY > HTML embedded Web server for a response, the response to indicate what the browser shows the contents of; JavaScript is used to achieve the basic functions of the client. Recently, other technologies such as Java applet, and ActiveX components began to pop up, but the Web server's response in the first issue, the vast majority, or in HTML, this includes the server for the notice issued by the client beyond what HTML technology to take over behind the implementation of the process response.

What is the business logic layer?

Repeat business logic layer of functionality into a single server (three-tier architecture), also can be distributed to multiple servers (n-tier architecture). Business logic layer include the following three parts:

Access (access and save) the database layer of data.

Obtain data from that layer.

Perform the necessary operations and / or processing data.

Business logic layer to get data from the database layer, that layer based on the data processing needs. Business logic layer also provides access to the data layer and database layer according to the needs of its processing.

CMS business logic layer of the many logic and the other two layers of the transfer (interfacing) related. In Microsoft.NET, because ADO.NET,. NET remoting and Web servers to help, most of the complexity of this logic are reduced. With. NET after, the logic level of the most complex logic that is used to calculate the transaction and processing data task was (with C # 或者 Managed C + +).

What is the database layer

Database layer name tells us what its mission is; It is used to deal with CMS data. A less interesting place is that it's data storage and retrieval is not limited to the database. It can be a single or a series of flat file (flat file), may be the XML format. However, the data often still exist in the database. Database