Question: How to Use Memcached in PHP?

Answer

Memcached is an open-source, high-performance, distributed, and in-memory caching system. It is used to speed up dynamic web applications by reducing the database load. In this answer, we will discuss how to use Memcached with PHP.

Prerequisites

Before proceeding, make sure that you have installed the Memcached server and the PHP Memcached extension on your system. You can install the Memcached server on Ubuntu using the following command:

sudo apt-get install memcached

To install the PHP Memcached extension, run the following command:

sudo apt-get install php-memcached

Connecting to Memcached from PHP

Once you have installed both the Memcached server and the PHP Memcached extension, you can connect to Memcached from PHP using the Memcached class provided by the PHP Memcached extension.

Here's a simple example of how to connect to a Memcached server and store a value in it using PHP:

// Create a new instance of the Memcached class
$memcached = new Memcached();

// Add a server to the pool
$memcached->addServer('localhost', 11211);

// Store a value in Memcached
$memcached->set('key', 'value', 3600);

In the above example, we first create a new instance of the Memcached class. Then we add a server to the pool using the addServer method. The first parameter to this method is the hostname of the Memcached server, and the second parameter is the port number (11211 is the default).

Finally, we store a value in Memcached using the set method. The first parameter to this method is the key under which to store the value, the second parameter is the value to store, and the third parameter is the expiration time (in seconds).

Retrieving Values from Memcached

To retrieve a value from Memcached, you can use the get method of the Memcached class. Here's an example:

// Retrieve a value from Memcached
$value = $memcached->get('key');

if ($value !== false) {
    echo "The value of 'key' is: " . $value;
} else {
    echo "'key' not found in Memcached";
}

In the above example, we retrieve the value of the key 'key' from Memcached using the get method. If the key exists in Memcached, its value will be returned, otherwise the value false is returned.

We then check if the value returned by get is not equal to false. If it is not equal to false, we print the value, otherwise we print a message indicating that the key was not found in Memcached.

Conclusion

In this answer, we have discussed how to use Memcached with PHP. We have looked at how to connect to a Memcached server, store values in Memcached, and retrieve values from Memcached.