A brief analysis of 5,6,7 of "large Web site Technology architecture: Core Principles and Technical analysis"

These three chapters highlight the high availability, scalability, and scalability of the site architecture.

The 5th chapter mainly describes the high availability of the website architecture. It is almost impossible to ensure that a site is always fully available. The industry uses a number of 9来 to measure site availability, using failure 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. For the company, usability is related to the survival of the site, and for individuals, usability is related to personal performance promotion. So to ensure that the site is available, any heavy and long way.

For the system we are designing, as far as usability is concerned, I think I can add a feature that can be recovered after deletion. Create a new log feature to make it easier for users or designers to find the site's flaws. Then, as far as ease of use is concerned. I think the first thing to do is to optimize the JavaScript code for the interface. Ensure the accuracy of the code. and make it faster to process.

The 6th chapter mainly discusses the scalability of the Web site architecture, the so-called site architecture scalability, that is, do not need to change the site's hardware and software design, simply by changing the number of servers deployed to expand or reduce the site's service processing capacity. To achieve the scalability of the Web site, the key technology is how to build a good server cluster. To achieve a good goal, it is required each time the expansion and reduction of the server, the impact on the entire site is minimal. The CAP principle is to choose to harden the availability and scalability of the distributed storage system, and to some extent abandon consistency. The CAP principle is important to the design of scalable distributed systems and improperly caters to a wide variety of needs, which can make design difficult to sustain. Our system has a large amount of statistical data. Our site can be modified at any time, such as the release of new features, it is necessary to close the original application on the server, re-deployment of new applications, the entire process requirements do not affect the user's use. To minimize the impact on users, publishing scripts are typically used to complete a publication. After rigorous testing, software deployment to the server or the problem, the main reason is that the test environment and the online environment is not the same, so when we publish the site, we have to publish the test code to the pre-release machine, verify that the system is not a problem before the official release.

A Web site with a well-scaled architecture design is always in front of business development, ready for business to handle more access and services, and when business is needed, simply deploy and implement a simple deployment of a server, and the technical team can rest assured.

As far as our system is concerned, there are not too many users to access. So the scalable design here does not do too much elaboration.

The 7th chapter mainly discusses the extensibility of the Web site architecture, the so-called extensibility, refers to the existing system to the smallest of the circumstances, the system function can continuously expand or enhance the ability. Performance in system infrastructure stability does not require frequent changes, less reliance and coupling between applications, and agile response to demand changes. We want the site architecture to be extensible. The development of low coupling is a necessary condition. Low-coupling systems are easier to extend, low-coupling modules are easier to take, and a low-coupling system design makes development and maintenance easier and more manageable. Large Web sites typically use distributed Message Queuing to reduce the coupling of the system. And the use of distributed services to build a reusable business platform. In the use of the database, using a NoSQL database that supports the columnfamily structure, when creating a table, you only need to make a columnfamily name, no need to make a field, you can write the data again, in this way, the data table can contain millions of of the field, Use the application data structure to scale freely. At query time, you can query by specifying the name and value of any field.

A Web site with a scalable architecture that enables faster development of new products. The efficiency of development is greatly improved.

As far as our own systems are concerned, the design of extensibility is primarily to make each file function single. That is, a file is only responsible for one function. and encapsulate it individually in a class. So that we need what function, directly call the encapsulated class can. It not only improves efficiency. and make our source code more orderly.

A brief analysis of 5,6,7 of "large Web site Technology architecture: Core Principles and Technical analysis"