Introduction To Memcached Basics

What is Memcached?

Memcached is an open-source, distributed memory caching system that is used to speed up dynamic web applications by alleviating database load. It works as a key-value store where data is stored in RAM, making it easily accessible, resulting in faster retrieval times compared to fetching data from a database.

How Does Memcached Work?

Memcached operates by storing data in memory (RAM) using a simple key-value pair format. When an application needs to retrieve data, it first checks if the data is available in Memcached. If it is found, it is returned to the application. If not, the application retrieves it from the database, stores it in Memcached for future requests, and then returns the data.

This process significantly reduces the number of database queries, which enhances application performance, especially under high load conditions.

Key Features of Memcached

High Performance: Memcached can handle millions of requests per second for small objects.
Simple API: Memcached provides a simple and easy-to-use API for developers.
Scalability: It can be easily scaled out by adding more servers to the pool.
Flexible Data Storage: Supports various data types, such as strings, objects, etc.
Open Source: Memcached is free to use and has a large community supporting it.

Basic Commands

Memcached provides several commands for storing and retrieving data. Here are some of the basic commands:

set - Store a value in Memcached.

set key value [flags] [expiration]

get - Retrieve a value from Memcached.

get key

delete - Remove a value from Memcached.

delete key

Example Usage

Here is a simple example of how to use Memcached in a PHP application:

PHP Code Example:

<?php
// Create a new Memcached instance
$memcached = new Memcached();
// Add server(s)
$memcached->addServer('localhost', 11211);

// Set a value
$memcached->set('username', 'john_doe', 300); // Expires in 300 seconds

// Get the value
$username = $memcached->get('username');
echo $username; // Outputs: john_doe
?>

Conclusion