Large Web site Technical architecture Read NOTE 2

Large Web site Technical architecture Read NOTE 2

The second major reading of the second article of the architecture, read the instantaneous response, the high performance of the site, foolproof, the site's high-availability architecture, never-ending, web site of the scalability of the architecture.

Website performance is an objective indicator, can concretely reflect the response time, throughput and other technical indicators, but also subjective feelings, and feel is a specific participant related to the subtle things, the user's feelings and engineers feel different, different user experience is different. Website Performance testing is the premise and foundation of performance optimization, and is also the inspection and measurement standard of performance optimization results. There are different standards for website performance in different viewing angles, and there are different optimization methods. For some software engineers, when it comes to website performance, it's usually different from what users say. The main concern of developers is the performance of the application itself and its related subsystems, including response delay, system throughput, concurrency processing power, system stability and other technical indicators. The main optimization methods are using cache to speed up data reading, using clustering to improve throughput, using asynchronous messages to speed up request response and peaking, and using code optimization to improve program performance. Operators are more concerned with infrastructure performance and resource utilization, such as network operator bandwidth capability, server hardware configuration, data Center network architecture, server and network bandwidth resource utilization. The main optimization means are the construction optimization backbone network, the use of cost-effective custom server, the use of virtualization technology to optimize resources. This number also reflects the load characteristics of the system in terms of the number of simultaneous requests that the system can handle, and for the Web site, the number of concurrent users, that is, the number of simultaneous users submitting the request. and Web site concurrent users corresponding to the number of online users, the current number of users of the site and the number of users of the site system, the total number of users may access the system, for most sites is the number of registered users, the number of comparative relationship is: Site system users more than the number of online users of the site more than the number of concurrent users. At the beginning of the website product design, product managers and operators need to plan the number of users of the website system at different stages of development, and based on this, the number of online users and the number of concurrent users is estimated according to the product characteristics and operation means. These indicators will become an important basis for system non-functional design. In reality, often see some web sites, especially e-commerce sites, marketing staff cheerfully to play advertising discounts and promotions, users will be excited to buy, the results of activities just beginning, because the number of concurrent users more than the maximum load and slow response, impatient users constantly refresh the browser, resulting in a higher number of system concurrency, Finally, the server system crashes, and the user's browser displays and ends. In this case, it is possible that the site is not sufficiently prepared for technical preparation, or it may be that the operator mistakenly evaluates the number of concurrent users caused.

Review the development history of the website architecture, the history of Web site architecture is a constant to add a server to the site.  As long as the engineer can add new machines to the Web site's server cluster. As long as the newly added server can linearly improve the overall service processing capability of the website, the site does not have to worry about growing users and access.

Large web site technology architecture Read Note 2