Introduction to Memcached

Memcached is a distributed memory data caching system commonly used to improve the performance of dynamic web applications. Its main function is to cache hot data from databases or APIs in memory, thereby accelerating access to these data. Memcached was created by Brad Fitzpatrick in 2003 and was originally developed to address the scalability issues of his website LiveJournal. It was first developed and maintained by Danga Interactive and later became an open source project for Memcached. Currently, Memcached is maintained and supported by an open source community. Memcached is suitable for application scenarios that require frequent reading and modification of data, especially in large-scale distributed systems. It is widely used in fields such as database caching, content distribution networks (CDNs), and session management in web applications. The advantages of Memcached include: 1. High performance: Due to the data being stored in memory, the read and write speed is very fast. 2. Distributed architecture: By adding more Memcached servers, storage capacity and access performance can be expanded to achieve horizontal scaling. 3. Easy to use: Memcached provides a simple key value interface, making it very easy to integrate into existing applications. 4. Cross platform support: Memcached can be used in multiple operating systems and programming languages. The drawbacks of Memcached include: 1. No persistence: As data is only stored in memory, data will be lost after system restart or crash. 2. No Data integrity protection: Memcached does not provide security functions such as data encryption and access control, and needs to provide data security and integrity protection by other means. The technical principle of Memcached is based on the distributed Hash table. It distributes data across multiple Memcached servers and determines which server the data should be stored on by hashing its keys. The client will also use the same hash algorithm to locate the server where the data is located and perform data access. From a performance analysis perspective, Memcached's read and write operations are very fast because the data is stored in memory and does not require disk IO operations. By adding more Memcached servers, storage capacity and access performance can be further improved. However, due to the fact that data is only stored in memory, Memcached has a high demand for memory, so sufficient memory resources need to be configured according to the actual situation. The official website of Memcached is: https://memcached.org/ Summary: Memcached is a high-performance distributed memory data caching system suitable for scenarios where data is frequently read and written in large-scale distributed systems. It has the advantages of high performance and ease of use, but lacks data persistence and security protection. Through the technical principle of distributed Hash table, Memcached realizes fast data access and scalability.