Memcache caching principle in PHP and its effect on cached data

With the development of the Internet and the rapid growth of data volume, caching technology is becoming more and more widely used. It can not only improve the access speed of the website, but also reduce the burden on the server. On the server side, Memcache, as a type of PHP caching technology, is widely used in access optimization of large websites. This article will introduce the principles of Memcache caching and its role in caching data.

1. The caching principle of Memcache

Memcache is a high-speed cache that improves the speed of data reading and writing by storing data in memory. In PHP, by using the Memcache extension, you can achieve fast reading and storage of data in PHP scripts.

The working principle of Memcache is as follows:

1. Data caching and reading

When the client accesses the data that needs to be cached, the Memcache client will first Query whether the data already exists on the cache server. If it exists, the cached data will be returned directly; if it does not exist, the Memcache client will query the data from the database and store it in the cache server.

2. The validity period of cached data

The validity period of Memcache’s cached data is set by the developer himself. When the validity period of cached data expires, the Memcache server deletes the data from the cache.

3. Handling when there is too much cached data

When there is too much cached data, the Memcache server can free up memory space by deleting expired and least-used cached data. Developers can also manually clear the Memcache cache to free up memory.

2. The role of Memcache in caching data

Memcache caching technology can greatly improve website access speed and reduce the burden on the server. The following is the role of Memcache in caching data:

1. Improve website access speed

Using Memcache caching technology can store commonly used data in memory and improve data access speed. The data access volume of large websites is very large. If data needs to be read from the database every time, it will seriously affect the speed of the website. Using Memcache caching technology, commonly used data can be cached in memory, improving data reading speed and responding to user requests quickly.

2. Reduce the burden on the server

When a large number of users access the website at the same time, it will cause excessive pressure on the server or even crash. Memcache caching technology can be used to store commonly used data in memory, reducing the burden on the server and improving the stability and reliability of the website.

3. Quickly restore data

In the event of server downtime or failure, by backing up and restoring cached data, you can quickly restore data and improve system availability. Using Memcache caching technology, data can be backed up to other servers to prevent data loss.

4. Data sharing

Memcache caching technology can realize data sharing. Multiple applications can share the same Memcache cache server to improve data utilization. It can store some commonly used data into memory and realize data sharing between multiple applications.

Summary:

To sum up, Memcache caching technology is a high-speed cache that can store commonly used data in memory, improve data reading speed, and reduce the burden on the server. Using Memcache caching technology can improve website access speed, increase website reliability and stability, and realize data sharing and other functions. In actual applications, Memcache caching technology needs to be optimized according to actual conditions to achieve the best results.

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