Read "Large Web site Technology architecture: Core Principles and Case studies" chapters v Chapter

Read "Large Web site Technology architecture: Core Principles and Case studies" chapters V, combined with our system, to analyze how to increase the corresponding functions, improve the system usability and ease of use.

These three chapters focus on the usability, scalability and scalability of the site.

　　

High-availability architectures are foolproof. It is almost impossible to ensure that a site is always fully available. We measure site availability through a magical digital 9来, using fault points to assess site availability. Usability indicators are important indicators of site architecture design, Web site availability can be seen, touch, and technology, operations, related to the performance of the parties are closely linked. A typical web site design follows the basic layered architecture model i.e. the application layer, the service layer, the data layer. The application layer is responsible for the specific business logic processing, the service layer is responsible for the provision of reusable services, the data layer is responsible for data storage and access. The site's availability architecture is designed to take into account downtime caused by actual hardware failures, as well as downtime due to site upgrade releases. Highly available service policies include tiered management, timeout settings, service demotion (shutting down non-core services), and so on. Highly available data is the most valuable asset, and the means to ensure high availability of data storage are primarily data backup and fail-over conversion mechanisms. Data backup can achieve complete data persistence, the invalidation mechanism is to ensure that the system is available. Ensuring that the site is highly available, foolproof, is a difficult process and requires more effort.

For our system, friendly interface style, simple and convenient operation, reasonable structure layout, good hints are necessary, to improve ease of use is very helpful. The table design needs to provide the user the good visual effect, reduces to the operator to bring the visual fatigue, the operation hint should be easy to understand, uses the accurate appropriate language. Three-level menu implementation algorithm to the time complexity of the standard, display fast, no wait.

The usability index of the website is an important index in the design of the website architecture, the external is the service promise, the internal evaluation index. So, a highly available website architecture is what a company needs to have. Among the many factors that affect the usability of the website, hardware failure is the norm, and the main purpose of the high-availability architecture design of the website is to ensure that the service is still available, the data is still saved and can be accessed when the server hardware fails.

High-availability applications. The first is the failover of the stateless service through load balancing, which simply means that when a server in a cluster of multiple servers goes down, the load Balancer server discovers the server through a heartbeat detection mechanism and then sends requests to that server to the other servers on the cluster. The second is the application server cluster session management, under the cluster environment, Session management of the main means are: 1.Session replication, so that each server in the cluster to save all users of the session information; 2.Session binding, that is, the use of load-balanced source address hash algorithm to bind the session to a specific server, to ensure that the session always in this Server, but once the server that holds the session goes down, then all the sessions on that server are gone, so few sites use this algorithm. 3. Using cookies to record the session, this is easy to use, high availability, but there are some drawbacks to limit 4. Session server, the use of independent deployment session server cluster Unified management session, application server every time the session, access to the session server.

　　

Read "Large Web site Technology architecture: Core Principles and Case studies" chapters v Chapter