Comparison of C / S Structure and B / S Structure Technology Characteristics
The so-called B / S structure is only installed to maintain a server (Server), and the client uses a browser (Browse) running software, the browser / server structure.
The advantage of the B / S structure is that the maintenance is convenient, and it can reduce the overall cost. The client runs the software, just like we usually browse the web, there is a browser (usually IE5.0), do not need to install other software. And the software can be run through the telephone line. All software of the B / S structure is all maintained, and the upgrade work is only performed on the server, and the client can get the latest version of the software.
Compared to the C / S structure, although the C / S structure is greatly improved, it is very important than B / S, shortcomings, and insufficient compared to B / S.
First, B / S is greatly reduced by the maintenance work of C / S. Each client of the C / S structure must be installed and configured. If a company has a total of 50 client sites using a C / S structure software, then when this software is very small, the system maintainer must make such maintenance; The server is updated to the latest version; uninstalling the original software of the client, install a new version, then set, the most terrible is 50 times that the client's maintenance work must be repaired. If some of these clients are in another place, the system maintainer must also run to the place to uninstall, install, and set up. If a client, forget to make such maintenance, the client will encounter the inconsistency of the version and cannot work. And the B / S structure, the client does not have to be installed and maintained. If we replace the software of the C / S structure of the previous enterprise to the B / S structure, we look at the software upgrade, how the system maintainer maintains: System Maintenance as long as the server upgrades to the latest version. Other clients, just log in to the system, it is already the latest version of the software.
Second, B / S relative to C / S can reduce the overall cost, and C / S software is generally two-layer structures. And B / S is three-layer structure. In the two-layer structure, the client accepts the user's request, the client is requested to the database service, the database service is submitted to the client, and the client calculates the data (may involve calculation, summary, statistics, etc.) and will result Present it to the user.
In the three-layer structure, the client accepts the user's request, the client proposes a request to the application service, the application service gets data from the database service, the application service calculates the data and submits the results to the client, and the client is presented to the results user.
The difference between the two structures is that the client participates in the two-layer structure, and the client does not participate in the operation in the three-layer structure, just a simple receiving user request, showing the last result. Since the client in the three-layer structure does not need to participate in the calculation, the computer configuration requirements for the client's plan computer computer configuration requirement are relatively low.
In addition, since the application service to the client only transmits the final result, there is fewer data, and the telephone line can be trusted. The C / S two-layer structure is used, using telephone lines as transmission lines may be accepted because the speed is too slow. The configuration of B / S using the three-layer structure can be to improve the configuration of the server and reduce the configuration of the client. This increased only one server (application service and database service can be placed in the same computer computer), while the reduction is the price of dozens of client machines. It has reducing the role of overall cost.
1 C / S Structure and B / S Structure C / S Structure B / S Structure Adopt Intranet Technology Applicable to LAN Environments Adopt Internet / Intranet Technology Applicable to WAN Environment Connecting User Number When User Quantity Increased performance significantly decreased support Many customers can dynamically configure the web server application server based on the traffic to ensure that the system performance clients must install the application client only the standard browser system extension maintenance complex system extension maintenance simple code can be reused, and the object-oriented technology code can be used. Reusstability development costs less development cycle is less developing cycle longer. Any commercial application has three major categories. The first class and the user's interaction related human-machine interface is how the user uses the application. Such tasks may be called the computing process and program processing flow completed by the second class presentation. The second class and the application is related to the application logic layer Application Logic. The last type of query update and data management of the data The mainstream technology known as the data resource layer Data And Resource2 C / S structure The mainstream technology developed in the early 1990s is that the client / server mode Client / Server is referred to as the C / S mode it is. Complete application is distributed On the client client and server server, it represents the layer and the application logic layer to the client data resource layer distribution to the server. The client completes a certain computing task and performs a certain service service or by a certain protocol and interface and server communication request to complete a certain service service or Data is required. The C / S system is suitable for small or medium-sized local area network environments. The C / S mode development system uses a lower development cycle in cost than B / S mode but there are many restrictions. First, the database system is Each user creates a connection connection when the number of users increases. The performance will be significantly declining, especially when more than a critical point, the entire system performance will drop sharply to an unbearable level. Secondly such systems are not suitable for use in a wide area network environment LAN environments for medium or small-scale, certain remote users can also be connected. Thirdly, their application logic is difficult to rewrite the change of usual application logic means rewriting the client's end code and needs to update all client programs so large scale. Deploying C / S apps will bring a lot of system management problems, although the C / S mode development system uses a lower development cycle in cost, short-term shortcomings in B / S mode but since the C / S mode described above. To develop programs with strong scalability, there is a very difficult 3 B / S structure characteristic based on the B / S mode three-layer architecture to distribute the layer application logic data resource layer into different units. Representation The dynamic page of the browser and the web server constitutes a receiving user's processing request and handed over Use the server Application Server.
