Distributed cache is mainly used in high concurrency environment to reduce database pressure, improve system response speed and concurrent throughput. When a large number of read and write requests flood the database, the disk processing speed and memory is obviously not the same magnitude, so before the database with a layer of cache, can significantly improve the system's responsiveness and reduce the database pressure. Because of the limited memory resources and load carrying capacity of a single machine, and the large use of local caches, the same data can be stored in multiple nodes, resulting in a significant waste of content resources, thus generating a distributed cache. In large Web sites, caches are primarily used to store hotspot data to relieve database stress or to save application context-sensitive information. For example, a session server cluster in a large web site is built using a distributed cache.
Distributed Cache system-Definition