Caching strategies commonly used in J2EE development

1、 What is cache? 1. Cache is a special memory subsystem of cache memory, in which frequently used data is copied for fast access. 2. Any structure between two kinds of hardware / software with large speed difference and used to coordinate the data transmission speed difference between them can be called cache

2、 Cache classification 1. System architecture diagram based on Web Application

2. Cache can exist at different levels of the system architecture in order to speed up access

3、 Operating system cache 1. Disk cache provided by the file system: the operating system will put the frequently accessed file contents into memory and managed by the file system. 2. When an application accesses disk files through the file system, the operating system reads the file contents from the disk cache, accelerating the file reading speed. 3. Disk cache is automatically managed by the operating system, Generally, there is no need for manual intervention, but sufficient physical memory should be ensured so that the operating system can use as much memory as possible as disk cache to accelerate file reading speed. 4. Special applications have high requirements for file system disk cache, bypass file system disk cache, directly access disk partitions, and implement disk 5 and cache policies by themselves

4、 Database cache 1. Importance

2. Cache policy A. query cache

b、Data Buffer

5、 Application cache 1. Object cache

2. Query cache

3. Page caching A. function

b. Classification I. static dynamic page

2. Servlet cache

3. Page internal cache

6、 Web server side caching

7、 Browser caching based on AJAX