Web site scalability:
No need to change the hardware and software design of the site, only you can expand or reduce the service processing capability of the site by changing the number of servers deployed.
The traditional banking system, from the outset clearly designed to know a large site architecture, large-scale systems, are generally put money to build the hardware.
The Internet system, the business is relatively new, many while exploring the development side, a start can not plan out their size, can not have so much money to develop a large-scale system, not to a certain point and then re-create a system, only can cross the river by feeling the stones, the road began large-scale evolution of their systems from a low-cost PC servers.
In this gradual evolution, the most important technology is to use server clusters to enhance the processing power of the entire cluster by continuously adding servers to the cluster.
This is the scalability of the system architecture of the site, as long as the technology can do a linear relationship between added to the cluster server processing power and the number of clusters, this means that the site can continue to upgrade their scale.
Not only can stretch, shrink may also need to add the machine when such big promotion, after the big promotion, the machine can be reduced, the release of resources and cost savings.
Website is not necessarily big, not necessarily the big development, but must be scalable, highly available, high performance.
6.1 site architecture design flexibility
Scalability site is divided into two categories:
1, according to the function to achieve physical separation stretching, different service server deployments, provide different functions
2, single function achieved by stretching the cluster, multiple servers within a cluster deploy the same service, provides the same functionality.
6.1.1 physical separation to achieve different functions telescopic
Physical separation
Longitudinal separation (stratification after separation): partial separation of different business processes deployed on, for system scalability
Laterally separated (after separation operations segmented): separation of different service modules deployed, for system scalability
Lateral separation particle size can be very small, or even a key pages deploy a separate service, such as the electricity supplier for the site very important product detail page, shop page, search a list of pages, each page can be deployed independently, specialized maintenance.
6.1.2 single function achieved by stretching cluster size