"Large Web site Technology architecture: Core Principles and Case analysis" combined with demand collection system analysis

Read the "Large Web site Technology architecture: Core Principles and Case analysis," chapters V, combined with "Hebei Province, the major technology demand collection system", listing examples of the use of the analysis of usability and modifiable tactics, the above content is written into a 1500 words about the blog to explain your point of view.

Read the "Large Web site Technology architecture: Core Principles and Case analysis," The fifth chapter, the availability of a certain understanding, usability measurement and assessment. Have a certain understanding of the highly available Web site architecture. Internet companies are increasingly using PC-class servers, open-source databases and operating systems, which cost-effectively reduce availability, especially server hardware devices, and low-cost commercial-grade servers are a big probability event in a year, while those hard-to-read, high-intensity, regular drives The probability of damage is higher. Different business products are deployed in different server clusters. Every time a Web site is published, the service needs to be shut down and the system redeployed, the whole process equivalent to server downtime.

Since load balancing actually plays a high-availability role in the application layer, it is more than enough to provide services on only one server, even if there is very little access to an application, but if you need to ensure that the service is highly available, you must deploy at least two servers and use load balancing technology to build a small cluster. Session replication, session binding, the use of cookies to record the session, session server has a new understanding.

High-availability software quality assurance, in the site operation and maintenance practice, in addition to network, server and other hardware failures caused by the system availability risk, but also from the software system itself risk. Monitoring and collection of data. After reading the Internet to understand that not all services can be called asynchronously, for the acquisition of user information such calls, the use of asynchronous way to extend the response time, not worth the candle. An application that must confirm that the service invocation succeeds before proceeding to the next step is also not suitable for asynchronous invocation.

The sixth chapter introduces the scalability architecture of the Web site system, the most important technical means is to use the server cluster function, by constantly adding servers to the cluster to enhance the overall processing capacity of the cluster. "Stretched" means that the size of the site and the size of the server are always expanding. The scalability of the site design classification has a certain understanding of the functional differences between the two have a certain understanding, a class is based on the physical separation of functions to achieve scaling, a class is a single function through the cluster to achieve scaling.

Scalability for the application of the algorithm is still a lot of, consistent hash algorithm is the core theory of distributed cache. The CAP principle is to choose to harden the availability and scalability of the distributed storage system, and to some extent abandon consistency. I have a lot of shortcomings in the understanding and use of algorithms, and the understanding of algorithms is still very narrow. Through the Internet to understand that large sites are always partially using DNS domain name resolution, the use of domain name resolution as the first level of load are very means, that is, the domain name resolution of a group of servers is not the actual Web server, but also provide a load-balanced internal server, this set of internal servers to load balance, The request is distributed to the real Web server.

The seventh chapter introduces the extensible architecture. The extensibility architecture of the website: the ability of the system function to be continuously expanded and improved in the case of minimal impact to existing systems. Scalability is the ability to continuously expand and enhance the system's functionality with minimal impact on existing systems. The core idea is modularization and reducing the coupling between modules. The modules are deployed in a distributed, independent module that is physically decoupled from the modules on separate servers.

For the technology demand collection system, in the usability, the error detection, in the data operation and system operation can be limited reminders to avoid errors, report filling format, information input, authority allocation and so on, the system to monitor, to return to the error, to ensure the normal operation of the system, to avoid the generation of errors.

In the modifiable, tightly grasp the low cohesion high-coupling core idea, the system layer, even if errors can be at different levels of the timely modification, to make the best solution.

For the technology demand Collection system architecture, there are a lot of programs to understand the learning place, will learn more.

Large Web site Technology architecture: Core Principles and case studies combined with demand collection system analysis